Improving
the Drive Clutch Assembly in a Cub Cadet
- This page was last updated 8/31/08. (Click Refresh.)
- Improving International Harvester's "Original" Cub Cadet (belt-to-clutch-drive) Clutch Assembly (Updated 11/24/08)
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On the direct-drive Cub Cadet, power from the engine is transferred to the transaxle through the clutch assembly and driveshaft. If the clutch is worn or if stock (OEM) parts are used, the clutch may slip and little power or torque will be transferred, especially if pulling with a big engine in a fast gear. Remember: towards the end of the track, if the tires don't spin or the engine bogs down, then the clutch will slip or something elsewhere will possibly twist or break.
Depending on the class your tractor is going to pull in and engine size/modifications, there are many variations in which clutch/driveshaft design and carrier/axles to use. Listed are the weakest to the strongest:
- For the driveshaft material, there's mild steel, stress proof steel, chrome-moly steel and stainless steel.
- As for the clutch, there's the single OEM Cub Cadet fiber clutch disc with a stiffer pressure spring, a single aluminum clutch disc, also with a stiffer pressure spring, double OEM Cub Cadet clutch discs with a stiffer pressure spring, the metallic clutch disc with a stiffer pressure spring, multiple clutch discs (Vogel) with a stiffer pressure spring, VW clutch/pressure plate/flywheel, etc.
- And as for the carrier and axles, there's the OEM Cub Cadet heavy duty one-piece carrier with either coarse or fine spline axles, OEM Cub Cadet's (MTD) two-piece fine spline carrier and axles, Ford Pinto carrier and axles, Chrysler's 7-1/4" carrier and axles, and Ford's 8" carrier and axles.
Using Quality Driveshaft Material Is Important!
Most driveshafts are likely to
break at the second roll-pin hole, just in front of the throw-out (clutch
release) bearing. Because that's where the most vibration usually occurs.
They also break just behind the pressure spring,
in front of the pillow block bearing, due to temporary frame twisting (narrow
frames) when pulling. If this happens, it's best to install a
split locking collar. Mainly what makes a driveshaft
break at 4,000+ rpm is either poor workmanship, poor quality material,
out-of-balance rotating parts, 
lack
of a center support bearing (pillow block bearing) near the center of the
driveshaft and/or severe "flexing" of the tractor's frame (only with a big
engine that's in a narrow frame tractor). If quality driveshaft material
is used, and if the rotating parts are precision balanced and if a carrier
bearing is also installed (above 4,000 rpm. The factory setting of maximum
rpm for virtually all small gas engines, including all of Kohler engines
is 3,600), the driveshaft could possibly last the life of the tractor. Even
when used in high-performance conditions.
Remember, in the direct-drive Cub Cadet, the entire clutch/driveshaft assembly rotates the same speed as the engine. For reliability in a highly modified tractor that turns well above 4,000 rpm, the driveshaft must be made of quality, solid hardened steel that can resist torsional twist. Such as 1144 stress-proof steel, heat-treated 4140 chrome-moly steel or 304 alloy stainless steel.
- Mild steel (cold rolled; 45,000 p.s.i. strength; about the same as OEM material) cost the least, and can be safely used in a basic stock tractor with an engine that's limited to 4,000 rpm or for non-pulling applications. It's obviously easy to bore holes through.
- Stress-proof steel is heat-treated, which makes it very strong (95,000 p.s.i. strength, which is about twice stronger than OEM driveshafts). It'll flex with slightly out-of-balance rotating parts at high rpm then return to its original straightness when the speed is reduced. It's easy to bore holes through.
- Heat-treated chrome-moly steel is another quality material to use. It comes in various hardnesses; from 60,000 to 100,000 p.s.i. strength. It's somewhat easy to bore holes through.
- 304 alloy stainless steel is much more rigid than any of the above metals (130,000 p.s.i. strength) and works excellent for use as driveshaft material. It requires a little more effort to bore holes through.
If you bought a clutch-drive Cub Cadet garden tractor with no driveshaft assembly and would like to know the length of the driveshaft and measurements of where the roll-pin holes are to be drilled, details and measurements are as follows: (Click the links below Ê to see what each tractor looks like. Compliments of http://www.geocities.com/jluckeycub)
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For all narrow frame Cub Cadet (models
70,
71,
72,
73,
100,
102,
104, 106,
122,
124 and
126), the driveshaft
is 18-3/16" long. NOTE è If your
tractor is equipped with a creeper drive unit, the driveshaft is 13-1/2"
in overall length. The roll-pin hole for connecting to the input shaft on
the creeper drive (#4 hole in drawing) is located at 13.250". Creeper unit
driveshafts are 13-1/2" long. Starting from the very front of the shaft...
- #1 roll-pin hole is located at 1.125".
- #2 roll-pin hole is at 2.255" or 2.630" with double clutches, using a 125" thickness center plate. If using a 3-puck metallic clutch disc, like the one that Midwest Super Cub sells, the 2nd hole will need to be drilled at 2.305".
- #3 roll-pin hole is at 9.250" or 9.625" with double clutches (using an 1/8" thickness center plate), or install a split locking collar here instead of drilling the 3rd hole.
- For a creeper drive unit, the #4 hole is located at 13.250".
- And the #5 roll-pin hole is located at 17.9375". When using a 3" aftermarket coupler (used in pulling competition to allow easier changing of the top pinion gear in the reduction housing without removing the driveshaft), make the driveshaft 1-3/4" shorter. The driveshaft needs to be 16-7/16" in length and the 4th roll-pin hole drilled at 16.1875".
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For the wide frame Cub Cadet models
86,
108 and
128 with
a solid mounted engine and solid rear coupler, the driveshaft is 1" longer
than the narrow frame models, which is 19-3/16" long. Creeper driveshafts
are 14-1/2" long. Starting from the very front of the shaft....
- The #1 roll-pin hole is located at 1.125".
- #2 hole is 2.255" or 2.630" with double clutches, using a .125" thickness center plate. If using a 3-puck metallic clutch disc, like the one that Midwest Super Cub sells, the 2nd hole will need to be drilled at 2.305".
-
#3 roll-pin hole is 9.250" or 9.625" with double clutches (using an 1/8"
thickness center plate), or install a split locking collar here instead of
drilling the 3rd hole. But the #3 hole can be located at a maximum of 9"
if you want the OEM spring to apply slightly more pressure on the clutch
disc. Or use a 5/8" long steel spacer or the OEM retainer cup (protective
sleeve) that originally comes on the driveshaft.
NOTE è Some wide frame clutch assemblies have a spacer with a grease fitting in it behind the throw-out bearing and some didn't. When rebuilding the clutch for yard work, this spacer can be reinstalled to lubricate the movement of the throw-out bearing on the driveshaft and then drill the 3rd hole at 10.500". Or for pulling purposes only, leave out the spacer and drill the 3rd hole at 9.250". - For a creeper drive unit, the #4 roll-pin hole is located at 14.250".
- And the #5 roll-pin hole is located at 18.9375". When using a 3" aftermarket coupler, make the driveshaft 1-3/4" shorter than stock length. The driveshaft will need to be 17-7/16" in length and the 4th (last) hole is drilled at 17.1875".
-
For the wide frame Cub Cadet models
800,
1000 and
1200 with
an ISO mounted engine and rear flexible coupler, the OEM driveshaft is 19-1/8"
long with use of the OEM equipped 5/8" diameter steel ball (IH design) and
19-3/4" long with the pointed end (MTD design). If your tractor is equipped
with a creeper drive unit, the driveshaft is 14-3/8" in overall length. Starting
from the very front of the shaft the roll pin locations are as follows:
- #1 roll-pin hole is located at 1.125".
- #2 roll-pin hole is at 2.255" or 2.630" with double clutches, using a .125" thickness center plate. If using a 3-puck metallic clutch disc, like the one that Midwest Super Cub sells, the 2nd hole will need to be drilled at 2.305".
-
#3 roll-pin hole is at 9.250" or 9.625" with double clutches (using an 1/8"
thickness center plate), or install a split locking collar here instead of
drilling the 3rd hole. But the #3 hole can be located at a maximum of 9"
if you want the OEM spring to apply slightly more pressure on the clutch
disc. Or use a 5/8" long steel spacer or the OEM retainer cup (protective
sleeve) that originally comes on the driveshaft.
NOTE è Some wide frame clutch assemblies have a spacer with a grease fitting in it behind the throw-out bearing and some didn't. When rebuilding the clutch for yard work, this spacer can be reinstalled to lubricate the movement of the throw-out bearing on the driveshaft and then drill the 3rd hole at 10.500". Or for pulling purposes only, leave out the spacer and drill the 3rd hole at 9.250". - For a creeper drive unit, the #4 roll-pin hole is located at 13.250".
-
And the #5 roll-pin hole is at 18". When using a 3" aftermarket coupler,
make the driveshaft same as the one for models 86, 108 and 128. (17-7/16"
in length and the 4th (last) hole is drilled at 17.1875".)
NOTE è This particular driveshaft use an OEM equipped 5/8" diameter steel ball on the end (rear) that presses against and swivels on the input shaft in the transaxle when the clutch pedal is depressed. Be sure to apply grease on the ball to prevent wear when reinstalling the driveshaft. If the ball is not used, and a solid coupler is installed, the engine must be mounted solid.
NOTE è If tractor is equipped with ONE rubber disc, the coupler will need to be 2-7/8" long. The roll-pin holes are located .375" from each end, or 2.500" from the other hole.
NOTE è If tractor is equipped with TWO rubber discs, the coupler will need to be 3.25" long. Roll-pin holes are located .375" from each end, or 3" to the other hole.
NOTE è When using a 3" aftermarket coupler, make the driveshaft 1-3/4" shorter than stock length. The driveshaft will need to be 17-7/16" in length and the 4th (last) hole drilled at 17.1875".
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For the model 582 Cub Cadet...
- The driveshaft in the 582 models made by IH (tractors that's red in color) are 19-1/8" long with use of the OEM equipped 5/8" diameter steel ball and 19-3/4" long without the ball. This particular driveshaft use a 5/8" diameter steel ball on the end (rear) that presses against and swivels on the input shaft in the transaxle when the clutch pedal is depressed. Be sure to apply grease on the ball to prevent wear when reinstalling the driveshaft. If the ball is not used, and a solid coupler is installed, the engine must be mounted solid.
- The driveshaft in the 582 models made by MTD (tractors that's yellow and white in color) are 19-3/4" in overall length. It has a 30º pointed end that fits into, presses against and swivels on the input shaft in the transaxle when the clutch pedal is depressed. Be sure to apply grease on the pointed end to prevent wear when reinstalling the driveshaft.
-
Each of the 582 OEM driveshafts have 6 roll-pin holes and use a flexible
joint on the end. Starting from the very front of the shaft, the #1 roll-pin
hole is located at 1.125", #2 hole is 2.250" (or 2.625" with double clutches),
if using a 3-puck metallic clutch disc, like the one that Midwest Super Cub
sells, the 2nd hole will need to be drilled at 2.305",.#3 hole is at 9.125"
(or 9.500" with double clutches, or install a split locking collar instead
of drilling the 3rd hole); #4 hole is at 10.500"; #5 hole is at 13.0625"
and the last hole (#6) is at 17.750".
NOTE è When using the 3" aftermarket coupler, the driveshaft needs to be 18" in length and the 4th hole drilled at 17.750".
NOTE è If your 582 tractor is equipped with a creeper drive unit, the driveshaft is 14-3/8" (IH) and 14-7/8" (MTD) in overall length. The roll-pin hole for connecting to the input shaft on the creeper drive (#5 hole on the shaft) is located at 13.0625".
NOTE è Some 582 clutch assemblies came with a spacer behind the throw-out bearing that have a grease fitting in it and some didn't. When rebuilding the clutch for yard work, this spacer can be reinstalled to lubricate the movement of the bearing on the driveshaft and drill the 3rd hole at 10-1/2" or for pulling purposes, toss the spacer and drill the 3rd hole at 9-3/8".
-
And almost every model of the spread frame Cub Cadets (that's made by IH
and MTD) are hydrostatically driven. If converting one of these tractors
into a clutch drive, the driveshaft will need to be 19-3/16" long (same length
as the IH wide frame models). The roll-pin holes are located in the same
locations as the ISO-mounted engine wide frame tractors.
Exception: the driveshaft in the spread frame models 1050 and 1535 Cub Cadets with an ISO-mounted engine and rear flexible coupler, the driveshaft is 21-1/2" long. Starting from the very front of the shaft, the #1 hole is located at 1.625", #2 hole is 2.750", #3 hole is 12.500" (or install a split locking collar instead) and the #4 hole is at 20.750". But the #3 hole can be located at 11-3/4" (3/4" forward) if you want the spring to apply slightly more pressure on the clutch disc. For connecting the driveshaft directly to the input shaft on the transaxle with a short tubular coupler, the shaft needs to be 22" long, and drill the #4 hole at 21-3/4". Be sure to install a set of my solid motor mounts, too. (For more information, please scroll down. Ê)
NOTE è If your model 1050 or 1535 tractor is equipped with a creeper drive unit, the driveshaft is 17-3/8" in overall length. The roll-pin hole for connecting to the input shaft on the creeper drive (#4 hole in drawing) is located at 16.125".
NOTE è Some wide frame clutch assemblies have a spacer with a grease fitting in it behind the throw-out bearing and some didn't. When rebuilding the clutch for yard work, this spacer can be reinstalled to lubricate the movement of the throw-out bearing on the driveshaft and drill the 3rd hole at 10-1/2" or for pulling purposes, leave out the spacer and drill the 3rd hole at 9-3/8" or at the same location in the OEM driveshaft.
NOTE: The above measurements are for a driveshaft with a single (1/4" thickness) clutch disc, and with a short tubular coupler on the rear of the driveshaft with the transaxle bolted to the frame in the stock location with factory drilled holes. Add 3/8" to the #2 and #3 holes if using a double-disc clutch set up.
If you're doubtful about the length of a particular driveshaft, to determine the exact length, measure between the end of the crankshaft threads to the input shaft on the transaxle (or creeper drive box), and then subtract 1/4". This will allow an 1/8" clearance on each end. Return to previous paragraph Ê
Advertisement:
If you need a quality steel driveshaft or coupler, please contact
me, Brian Miller, at A-1 Miller's Small Engine &
Specialty Shop (1501 West Old Plank Rd., Columbia, Missouri. 65203 |
Phone: 1-573-875-4033). Please call any day between 12 noon and 8:00 p.m.
Central time, and please be patient because I stutter. Fax: 1-573-449-7347.
You can also contact me through Yahoo! Messenger:
 Each driveshaft comes with
1/4" roll pin holes drilled and chamfered in the stock locations with the
exception of the 3rd hole which is optional for use with a split locking
collar. (3rd hole is optional for use with a split locking collar).
NOTE: These particular driveshafts are made to
order. When ordering, please specify the model of Cub Cadet you have and
possibly the exact length. I also make driveshafts for hydrostatic drive
Cub Cadets. By the way - these are not CNC machined.
I fabricate these manually on my milling machine.
Driveshafts for IH Hydrostatic Drive Cub Cadets -
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When to use a Split Locking Collar on the Driveshaft -
The
only reason a locking collar is needed behind the
pressure spring is for competitive pulling
and when the engine turns at very high rpms. When a pillow block bearing
is used to stabilize the driveshaft (prevent wobble) at very high rpms, the
collar prevents the driveshaft from breaking [when a hole is drilled for
the 3rd roll pin] and when or if the driveshaft flex under pulling strain.
If a stock engine will never run above 4,000 rpms, then a locking collar
shouldn't be needed on the driveshaft.
Note: when using a stainless steel driveshaft, the locking collar may slip rearward [when the clutch pedal is fully depressed] because stainless steel is very hard material and it has a "slick" surface. Sometimes using two collars will slip also. So to prevent the collar(s) from slipping, install flat washers behind the collar and in front of the pillow block bearing so the pressure will against the bearing and the bearing will hold the collar in position. And a locking collar will grip mild or stress proof steel with no problems. Return To Previous Paragraph
Advertisement:
| If you need a two-piece
clamp-on 5/8" i.d. shaft collar as mentioned and pictured above, please contact
me, Brian Miller, at A-1 Miller's Small Engine &
Specialty Shop (1501 West Old Plank Rd., Columbia, Missouri. 65203 |
Phone: 1-573-875-4033). Please call any day between 12 noon and 8:00 p.m.
Central time, and please be patient because I stutter. Fax: 1-573-449-7347.
You can also contact me through Yahoo! Messenger:
|
Do this only if the
front axle has been moved forward -
On the narrow frame Cub Cadets, if the front axle has been
moved forward, reinforce the frame rails where the engine mounting holes
are to reduce normal high-rpm engine vibration travel that could lead to
both frame and driveshaft breakage. To do so, stiffen the frame rails where
the engine mounting bolt holes are by welding two 1/4" thick steel plates
under the frame. Longer engine mounting bolts must be used, too. The reason
for this is because when the front axle center support is moved, the remaining
frame material isn't thick enough to hold up to the engine vibration.
For
the spread frame models with the ISO (rubber) motor mounts, replace the rubber
mounts with a set of my solid steel motor mounts or remove the rails and
fabricate a minimum 1/4" thick plate steel, set it at the right height and
weld it to the frame. But the engine mounting holes and oil drain plug hole
must be properly located (centered) and drilled in the plate first.
Return To Previous Page
How to remove the driveshaft/clutch assembly from a Cub Cadet:
- Remove the engine. The 3-pin clutch drive plate remains on the engine and it slides out of the driveshaft and clutch disc when the engine is removed.
- Unfasten the clutch release lever from the frame and the adjusting rod.
-
There's a roll-pin in the tubular or flex arm coupler that fastens onto the
input shaft in the transaxle. Remove it by using a 1/4" roll-pin punch and
a medium sized hammer.
NOTE: This particular roll pin is kind of hard to access from underneath the tractor, especially if it's narrow frame model. So the way I do it is I drill a 1" diameter hole on top of the frame in direct alignment with the pin, which makes it a lot easier to access. After I remove the pin and rebuild the clutch assembly, upon reinstallation, I use a socket in this hole to fasten a hardened steel 1/4" diameter [grade 8 or an Allen head] bolt in the coupler.
And for cosmetic reasons, I
cover up the hole with a chrome plated metal hole plug.
Sometimes the pounding will bend the input shaft when driving out the
roll pin. If this happens, the input shaft will need to be straightened (and
hope it doesn't break later because the metal has been weakened) or a good
used one will need to be installed. This is why I suggest to everyone that
a hardened steel 1/4" bolt should be used in the coupler because if they
ever need to remove the driveshaft again, removing a bolt would be a lot
easier than driving out a stubborn roll-pin, plus it'll be easier on the
input shaft.
- The driveshaft assembly then slides out of the tractor.
How to Disassemble the Clutch Components from the Driveshaft -
To disassemble the clutch components from the driveshaft, first place the front pressure plate hub on slightly open jaws of a bench vise and then use a 1/4" roll pin punch and a medium size hammer to drive out the roll pin. Then the pressure plates, clutch disc throw-out bearing and pressure spring should all slide off the driveshaft.
Coupler Dimensions -
NOTE: The overall length of these couplers is for better stability and
less vibration on the driveshaft and input shaft.
Narrow & Wide Frames1-3/8" long x .626" i.d. Roll-pin holes located at .375" from each end, and 1" to the other hole from the first hole. |
 |
Models 800, 1000 & 1200If tractor is equipped with ONE rubber disc, the coupler will need to be 2-7/8" long. The roll-pin holes are located .375" from each end, and 2.500" to the other hole from the first hole. If tractor is equipped with TWO rubber discs, the coupler will need to be 3.25" long. Roll-pin holes are located .375" from each end, and 2.875" to the other hole from the first hole. |
 |
3" Coupler / Model 5823-1/2" long x .626" i.d. Roll-pin holes are located at .375" from each end, and 3.125" to the other hole from the first hole. |
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NOTE: Many pullers convert the hydro models 109, 129, 149 and 169 (wide frames, solid mounted engine) and models 1250, 1450 and 1650 (wide frames, ISO-mounted engine) into a clutch-driven tractor. All that's needed are the clutch assembly with the hanger bracket for the release lever and a complete transaxle out of a model 86, 108 or 128 or models 800, 1000 or 1200 gear drive Cub Cadet. You'll need to install a set of my solid motor mounts if the tractor originally has rubber motor mounts, too. You'll also need the braking mechanism out of a wide frame Cub Cadet so the brakes will work.
|
Or
instead of making the above coupler, remove the rubber disc(s) and install
a nut that's made for 7/16" bolt between the two T arms, then fasten them
together with a couple of grade 5 bolts. See the picture to the right. This
would be better than the rubber discs. This is just as strong as a one-piece
coupler, and it cost a lot less. And be sure to install a set of solid motor
mounts, too.
Advertisement:
| If you need a coupler, please contact me, Brian Miller,
at A-1 Miller's Small Engine & Specialty Shop
(1501 West Old Plank Rd., Columbia, Missouri. 65203 | Phone: 1-573-875-4033).
Please call any day between 12 noon and 8:00 p.m. Central time, and please
be patient because I stutter. Fax: 1-573-449-7347. You can also contact me
through Yahoo! Messenger:
|
|
 Your worn OEM Cub Cadet coupler
repaired for $15.00 each, plus shipping.
I bore it and then install a steel sleeve for a snug fit on the driveshaft and input shaft. By the way - these are not CNC machined. I fabricate these manually in my lathe and on my milling machine. |
 Stock- and custom-length
couplers. Made of tough 3/16" wall 4140 chrome-moly steel. Any length up
to 6-1/2".
NOTE: Custom length couplers are made to order. When ordering a custom length coupler, please specify model of Cub Cadet, overall length and roll pin hole locations. By the way - these are not CNC machined. I fabricate these manually in my lathe and on my milling machine. |
 3" aftermarket
coupler. This particular coupler is used in the model 582 and in pulling
competition to allow easier changing of the top pinion gear in the reduction
housing without removing the driveshaft. With roll-pin holes drilled.
Made of tough 3/16" wall 4140 chrome-moly steel. $20.00 each, plus
shipping.
By the way - these are not CNC machined. I fabricate these manually in my lathe and on my milling machine. |
|
It's important that the roll-pin holes to be drilled centered in the driveshaft and coupler!
To accurately locate
and center roll-pin holes in a driveshaft and coupler is with the shaft or
coupler clamped in an aluminum angle in the slot on the table of a vertical
milling machine that has an electronic digital readout (DRO). But first center
the slot with the center of the spindle in the milling machine, then lock
the cross travel in position.
The correct way to drill the
holes for the roll-pins is to start with a 1/4" spotting (stubby) drill bit
to make a dimple (because a long drill bit will skate or wobble around on
the metal), then drill the holes with a longer 15/64" drill bit and then
finish enlarging the holes with a long 1/4" drill bit. Doing this will
ensure that the holes will be exactly 1/4" in diameter and not be too large
for the roll-pins. Then finish off each hole by chamfering them with
a 3/8" drill bit (in a drill press) so the roll-pins will go into each hole
easily.
Actually, for any size roll-pin, it's best to first bore the hole 1/64" smaller than the desired roll-pin size. Then finish drilling the hole with a .010" smaller drill bit than the actual roll-pin diameter.
NOTE - If a hole was [accidentally] drilled slightly too large for a roll-pin, a metric roll-pin that's slightly larger in diameter could possibly be used instead or a small spring-type roll-pin that's driven inside a larger one could probably be used also. Doing this would be better than wasting quality driveshaft material. The driveshaft wouldn't be weakened that much because of the slightly larger hole(s) either. Also, the slot in the rear pressure plate may need to be widened slightly with a flat file to accommodate the larger pin. Return Ê
Use quality spiral (or coiled) roll-pins for the job to prevent the possibility
of breakage. Spiral roll-pins are much stronger than the "spring" type roll-pins.
And all Cub Cadet driveshafts require the spiral roll-pins. Also, use a
quality-made 1/4" roll-pin punch tool to remove the roll-pins. And whenever
a roll-pin is removed, one end will probably get "mushroomed" or flared out.
Making reinstallation almost impossible. So before reinstalling used roll-pins,
bevel one end (grind to a dull point) to make the installation easier.
Advertisement:
 If you need some heavy duty replacement spiral (or coiled)
roll-pins for your driveshaft or 3-pin drive plate, please contact me, Brian
Miller, at A-1 Miller's Small Engine & Specialty
Shop (1501 West Old Plank Rd., Columbia, Missouri. 65203 | Phone:
1-573-875-4033). Please call any day between 12 noon and 8:00 p.m. Central
time, and please be patient because I stutter. Fax: 1-573-449-7347.
You can also contact me through Yahoo! Messenger:
|
For pulling applications, rubber motor mounts (and the flexible coupler at the rear of the driveshaft) absorbs horsepower, which must be transferred to the rear tires for full power to the track. The rubber motor mounts will also cause the engine to vibrate excessively at high rpms. Plus, with normal use of the tractor, rubber motor mounts could cause the flexible 3-pin drive plate and/or the driveshaft to eventually break. If a tractor that has rubber motor mounts and a flexible coupler is going to be used for pulling competition, definitely install some metal motor mounts.
Advertisement:
If you need a set of solid steel motor mounts, please contact me,
Brian Miller, at A-1 Miller's Small Engine & Specialty
Shop (1501 West Old Plank Rd., Columbia, Missouri. 65203 | Phone:
1-573-875-4033).Please call any day between 12 noon and 8:00 p.m. Central
time, and please be patient because I stutter. Fax: 1-573-449-7347. You can
also contact me through Yahoo! Messenger:
 Details include:
|
If the adjusting rod in your tractor is badly worn or if you bought a Cub Cadet without one, then here's the dimensions to make your own:
For all narrow frame Cub Cadets:
Start with a 3/8" diameter steel rod that's 10-1/2" in total length. The
3/8-24 NF threads are 4-7/8" in length. Install a nut on the threads for
the compression spring. Do not drill a hole for a cotter! (This will weaken
the rod, which could cause it to break.) The hole for the pedal return spring
is 5/32" in diameter. The long part is 9-3/8" to the inside of the bend.
The short part is 7/8" to the inside of the bend. NOTE: Heat the rod with
an acetylene torch to make the 90º bend. Because cold bending
may cause the metal to crack at the bend.
For the wide frame Cub Cadets:
Start with a 3/8" diameter steel rod that's 13-1/2" in total length. The
3/8-24 NF threads are 3-1/2" in length. Install a nut on the threads for
the compression spring. Do not drill a hole for a cotter! (This will weaken
the rod, which could cause it to break.) The hole for the outer cotter pin
is 5/32" in diameter. The inner cotter pin hole is also 5/32" in diameter
and located 1/2" from the first hole. The long part is 11-5/16" to the inside
of the bend. The short part is 1-13/16" to the inside of the bend. NOTE:
Heat the rod with an acetylene torch to make the 90º bend. Because
cold bending may cause the metal to crack at the bend.
Also, install the compression spring over the threaded end of the adjusting rod. The compression spring holds the release lever forward to take pressure off the throw-out bearing.
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If you bought an IH Cub Cadet, but didn't get the aluminum hub adapter or the 3-pin clutch drive plate with it (most people will let them go with the engine, when they sell just the engine), but want to fabricate these yourself, then the dimensions of these two parts are as follows:
-
Overall o.d. is 3" and overall height is 1.800".
- Center mounting hole is either 3/8" or 5/8" in diameter. This depends on what size the bolt or stud is on the end of the crankshaft.
- Diameter of the large hole (for the hub in the drive plate to fit into) is 1.500" i.d.
-
The bolt circle of the four 1/4" bolt holes is 2.1875". (This
is for the 1/4-20 NC bolts that secures the drive plate to the hub.) For
extreme accuracy, precision balance of the rotating parts and for safety
purposes, these holes must be drilled initially with a spotting or center
drill (to prevent skating) exactly 90º apart at a 1.09375" radius with
the hub clamped in a super spacer or indexing fixture (with a 3-jaw
self-centering scroll chuck) that's fastened on the table of a vertical milling
machine.
- The center of the 1/4" diameter solid steel pin that "locks" the hub to the flywheel , it measures 1.125" from the center of the hub to the center of the pin.
- And definitely use a thick steel flat washer in the center of the hub that measures 5/8" i.d. x 1.500" o.d. x 1/4" thick to secure it to the flywheel and to prevent from breaking the center of the hub.
By the way - The OEM aluminum clutch drive hub have been known to hold up well even in a highly modified garden pulling tractor as long as the original 1/4" thick x no less than 1-1/4" o.d. flat washer is installed under the flywheel nut or bolt, and using hardened 1/4" bolts with split lockwashers to fasten the drive plate to the hub. What makes the hub break is running out-of-balance clutch parts and/or mostly not installing the large flat washer as described above under the nut or bolt. Otherwise, they're pretty tough.
The dimensions of the solid OEM 3-pin drive plate are as follows:
-
The
outside diameter of the center hub (which fits inside the aluminum hub adapter)
measures 1.499" and is 7/8" in total length. (Length of hub includes thickness
of plate.) The step part is 1-3/8" in diameter. The step part is the same
depth as the thickness of the plate. Center hole in the hub is .875" i.d.
- The OEM plate measures .104" thick x 6" in diameter. For durability, and to make it more rigid (for pulling purposes, in other words), the plate could be made of either 1/8" or 3/16" thickness steel, depending on engine power output. (If you're going to fabricate it yourself, you might as well make it as tough as possible.) Center hole in the plate measures 1-1/4" i.d.
- The bolt circle for the three drive pins is 5.125".
- Each drive pin is 3/8" in diameter and measures 1.500" in length (when measured from behind plate to the end of pin).
- The bolt circle of the four 1/4" bolt holes (the ones that secures the drive plate to the aluminum drive hub adapter) is 2.1875".
- The hole for the pilot bushing is .875" i.d.
- And the bronze pilot bushing itself measures 5/8" i.d. x .877" o.d. x 7/8" in length.
- For precision accuracy, precision balance of the rotating parts and for safety purposes, with the plate (or center hub) clamped in a super spacer or indexing fixture (with a 3-jaw self-centering scroll chuck) that's fastened on the table of a vertical milling machine, the clutch pin holes must be drilled initially with a center or spotting drill (to prevent skating) exactly 120º apart for 3 drive pins and 60º apart for 6 drive pins at a 2.5625" radius. See chart below Ê.
- EXCEPTION: Models 800, 1000 and 1200 use rubber motor mounts. This means that the center hole in the plate will need to be made 1.500" in diameter. The four 1/4" bolts will center it on the aluminum drive hub. You'll also need to use a special made swivel pilot bushing in the drive hub, (to which is an OEM Cub Cadet part).
Degree Increments for a Super Spacer or Indexing
Fixture with a 3-Jaw Self-Centering Scroll Chuck -
(This chart also comes in handy for drilling 5 holes in axle flanges,
installing trigger screws in the trigger disc for the crank trigger ignition
and other projects. NOTE: Seven holes isn't shown because 360 can't be evenly
divided by 7.) [Print this chart]
| Number of holes to be drilled -> | 1st |
2nd |
3rd |
4th |
5th |
6th |
7th |
8th |
9th |
| For 2 holes -> | 0º |
180º | |||||||
| For 3 holes -> | 0º |
120º | 240º | ||||||
| For 4 holes -> | 0º |
90º |
180º | 270º | |||||
| For 5 holes -> | 0º |
72º |
144º | 216º | 288º |
||||
| For 6 holes -> | 0º |
60º |
120º | 180º | 240º | 300º | |||
| For 8 holes -> | 0º |
45º |
90º |
135º | 180º | 225º | 270º | 315º | |
| For 9 holes -> | 0º |
40º |
80º |
120º | 160º | 200º | 240º | 280º | 320º |
If you're using an OEM 3-pin clutch drive plate, and the plate next to where the roll-pin bosses (or collars) are tend to get bent, well, to fix this..
-
Straighten the pins/bosses (or
collars) with a hammer the best you can. Place a clutch disc over the
pins to insure that they're properly straightened.
- Securely weld each boss (or collar) to the plate. Try to apply an even amount of weld around each boss for proper balance and to reduce vibration.
- True all rotating clutch parts, including the drive plate, in a metal lathe that has a 3-jaw self-centering scroll chuck.
If the bronze pilot bushing in your drive plate is worn excessively, then this means that the pressure plates are badly out of balance and/or there was no lubricating grease applied to the bushing upon installation. In either case, the pressure plates will need to be trued up in a metal lathe for proper balance and so they won't wobble. Don't forget to resurface them, too. IMPORTANT: When resurfacing pressure plates and to insure true flatness, use a lathe that's in good condition with very little wear on the ways!
Advertisement:
| If you need a heavy duty, quality-made all-steel clutch
drive plate, please contact me, Brian Miller, at A-1
Miller's Small Engine & Specialty Shop (1-573-875-4033). Please call
any day between 12 noon and 8:00 p.m. Central time, and please be patient
because I stutter. You can also contact me through Yahoo! Messenger:
|
|
| Reconditioned
OEM 3-pin drive plates - These come with a new bronze pilot bushing and if needed, new spiral roll-pins. $30.00 each plus shipping. (When available.) These and the drive plates I make are for the narrow frame and solid-mounted engine wide frame Cub Cadets. (Models 70, 71, 72, 73, 86, 100, 102, 104, 108, 122, 124, 126 and 128.) These models have the solid mounted engine, no rubber motor mounts. If you want to use either of these plates in an ISO-Mount tractor (models 800, 1000 and 1200), then a set of my solid motor mounts must also be installed. And I can't make a flexible 3-pin clutch driver. They're an OEM Cub Cadet dealer item only. |
Hardened steel drive pins for my heavy duty drive plates and MTD's drive
plate. $10.00 each, plus shipping.
|
 Heavy
Duty, All Steel Clutch Drive Plates!Fabricated 3- or 6-pin, 3/16" plate thickness. Heavy duty, 1/3 thicker and 80% stronger than OEM; recommended for pulling tractors running unlimited rpms using a single or a double-disc clutch setup. Weighs under 2 lb.
NOTE: Three additional holes must be drilled in the clutch discs to match the location of the six drive pins. These precision made, high quality drive plates come with an installed new bronze pilot bushing and hardened steel studs (bolts) as drive pins. By the way - these are not CNC machined. I fabricate these manually in my metal lathe and on my milling machine. |
|
| Convert YOUR model 800, 1000 or 1200 3-pin clutch drive plate
to a solid plate: $50.00, plus return shipping. NOTE: Tractor requires
solid motor mounts also.
|
|
 Heavy Duty,
All Steel Clutch Drive Plate for when the engine is reversed in a Cub
Cadet!
Fabricated 3- or 6-pin, 3/16" plate thickness. Heavy duty, 1/3 thicker and 80% stronger than OEM; recommended for pulling tractors running unlimited rpms using a single or a double-disc clutch setup. Weighs about 3 lbs.
I can also make a heavy duty 3- or 6-pin clutch drive plate with a 1", 1-1/8" or whatever size you may need steel hub welded on it, so the hub can be mounted on the crankshaft, and the pilot bushing will be part of the drive plate, and not the crankshaft. I charge $90.00 each, plus shipping. NOTE: Three additional holes must be drilled in the clutch discs to match the location of the six drive pins. These precision made, high quality drive plates come with a new bronze pilot bushing (you install) and hardened steel studs (bolts) are installed as drive pins. And a 3/4" hole MUST be drilled into the end of the crankshaft for the pilot bushing. By the way - these are not CNC machined. I fabricate these manually in my metal lathe and on my milling machine. |
|
Resurfacing and Trueing Up Worn and Warped Pressure Plates -
For any clutch disc to hold well and to prevent slippage, both pressure plates must be perfectly flat and free of wear. Definitely have the pressure plates resurfaced in a metal lathe (with a 3-jaw self-centering scroll chuck) that has a sharp bit (preferably a new one). IMPORTANT: When resurfacing the pressure plates, and to insure true flatness, use a lathe that's in good condition with very little wear on the ways! And if the clutch disc is worn, but still reusable, have it resurfaced in the lathe as well. Chances are, the clutch disc is worn to match the wear on the pressure plates. For best clutch adhesion, it must be flat against flat for 100% clutch-to-pressure plates surface contact. But if you need a new clutch disc, the OEM Cub Cadet part number is 761-3002. (Sandwiched steel plate with asbestos lining.)
Warped pressure plates will allow a single or even double clutches to slip. They warp due to overheating and normal wear. When they get warped, they don't have full contact with the entire surface of the clutch disc. Whenever a new clutch disc is installed, rather if it's an OEM one or made of aluminum, the pressure plates should always be resurfaced and trued up in a metal lathe (with a 3-jaw self-centering scroll chuck). New OEM pressure plates are always stamped in a press and not machined in a lathe. This means they're not as flat or turn as true as ones that's been machined in a lathe. Therefore, if new or used pressure plates are going to be used for pulling, first have the outer edge trued up and then have the clutch contact area resurfaced in a metal lathe (with a 3-jaw self-centering scroll chuck). Resurface it all the way to the center of the hub. But don't remove too much metal! This will weaken them and could cause them to become concaved (bowl shaped or collapsed in the center), especially when used with an extremely stout pressure spring. Remove just enough metal so they clean up.
New OEM pressure plates are 3/16" (.188") thick. On the average, approximately .005" of metal is removed from the face of each pressure plate after it has been resurfaced. Removing this much metal won't weaken the plates whatsoever, even when used with a very stout pressure spring. IMPORTANT: When resurfacing the pressure plates, and to insure true flatness, use a lathe that's in good condition with very little wear on the ways!
With both pressure plates properly resurfaced, the single OEM fiber clutch, with 4-1/2" diameter pressure plates, has a total disc to plate contact area of 17.7 square inches. When doubled (as in double clutches including the 4-1/2" diameter center drive plate), it has a total contact area of 36 square inches. This is why double clutches hold so well in pulling. It's the same as using a bigger clutch. And it'll have even more contact area with 4-5/8" diameter pressure plates!
The aluminum disc on the other hand (as described in this web site), has a total contact area of 29.8 square inches. You may look at this disc and ask, "where's the friction material?" Well, the aluminum itself is the friction material. A single aluminum disc will adhere to (grip) steel a lot better than a single Cub Cadet OEM fiber clutch disc and it lasts a long time. (Some pullers have been using the same aluminum disc for 6 years!) Both of these type of clutches (the single aluminum and OEM clutch disc), when used with a stock Cub Cadet pressure spring (for stock classes) or a cultivator spring kit (for heavier tractors and high-horsepower classes), has been proven to hold very well in pulling, even in a highly modified 50+ c.i. garden tractor. If everything is machined, precision balanced, installed and adjusted correctly, the aluminum or double-disc clutch system including the driveshaft could possibly last the life of the tractor. Even when used in high-performance conditions.
If you want to fabricate your own pressure plates for a Cub Cadet, here's
the dimensions:
- First of all, the OEM pressure plates are made of 100% mild steel. But the plate can be made of stainless steel for heat resistance, less warping, and it works best for "slipping the clutch."
- Plate: 3/16" thickness and 4-1/2" diameter, but can be made a maximum of 4-5/8" diameter for more clutch disc contact. If you're going to fabricate them yourself, you might as well make them as large as possible.
- Hubs: length is .540" (NOT including thickness of plate), 1.375" in diameter.
- Drill a 1/4" [roll-pin] hole in the hub for the front pressure plate so it can be fastened to the driveshaft. The hole must be located .270" (half the length of the hub).
- Machine a 9/32" wide slot [for the roll-pin] .500" deep in the hub for the rear pressure plate so it can slide back and forth against the roll-pin for clutch engagement/disengagement.
-
Weld the hub to the plate in
two places. (See animated drawing above.) Then chuck the hub in a metal lathe
(with a 3-jaw self-centering scroll chuck). IMPORTANT: When resurfacing
the pressure plates, and to insure true flatness, use a lathe that's in good
condition with very little wear on the ways! Machine the plate until
it's perfectly round, and bore a .626" center hole. Remove from the lathe,
place it in a super spacer or indexing fixture with a 3-jaw self-centering
scroll chuck on a vertical milling machine table and cut the slot in the
rear pressure plate hub. Use a machine vise to accurately drill the hole
in the front pressure plate hub.
Save the Hubs!
If the discs in your pressure plates are heavily rusted, worn too thin or warped badly and resurfacing them in a lathe didn't do any good, instead of making two entirely new pressure plates, what you could do is remove the center hub from each disc with a hydraulic press and then reuse them to make two new pressure plates. This would save from having to fabricate a couple of new hubs.
Advertisement:
 If you need your pressure
plates professionally resurfaced and trued up, I can do them for $5.00 each
(plus return shipping). Please contact me, Brian Miller, at
A-1 Miller's Small Engine & Specialty Shop
(1501 West Old Plank Rd., Columbia, Missouri. 65203 | Phone: 1-573-875-4033).
Please call any day between 12 noon and 8:00 p.m. Central time, and please
be patient because I stutter. Fax: 1-573-449-7347. You can also contact me
through Yahoo! Messenger:
I can also rebuild your heavily rusted or damaged pressure plates for
$20.00 (plus shipping) each by welding your center hub into a new disc, then
resurface and true them in my metal lathe. My rebuilt pressure plates are
guaranteed to be between 4-1/2" to 4-5/8" in diameter, too!
|
But
if you'd prefer to have some new, one piece billet pressure plates, contact
Making the Aluminum Clutch Disc Engage Smoothly -
The OEM Cub Cadet cushion spring (as it is called in the early/narrow frame Cub Cadets) or teaser spring (as it is called in the later models/wide and spread frame Cub Cadets) goes between the rear pressure plate and throw-out bearing. It's purpose is to allow the rear pressure plate to move forward and gently press against the clutch disc without having a "jerky" clutch. It can be replaced with a steel spacer, and a lockwasher can be installed between the pressure plates (dead center of the clutch disc) for even smoother clutch engagement, especially when using an aluminum clutch disc with a heavy pressure spring. Do not use the lockwasher between the pressure plates if using the stock OEM pressure spring.
If the aluminum clutch disc doesn't engage smoothly, remove the 5/8" lockwasher from between the pressure plates and then install a thick flat washer, then the 5/8" lock washer and then another thick flat washer (so they'll all total to about 3/8" in height with the lockwasher uncompressed) in place of the teasing spring.
For a narrow frame tractor, the steel spacer will need to be 3/8" in length. For a wide frame, it's 5/8" long or use the OEM retainer cup (protective sleeve) that originally comes on the driveshaft.
If a retainer cup or "protective sleeve" is not used, sometimes the teaser
spring will become destroyed or distorted from normal use or by the extreme
pressure from a very stiff pressure spring.
To
prevent this from happening and to help the clutch(es) to engage more smoothly,
first replace the teasing spring with a piece of heavy wall round steel tubing
that measures 7/8" o.d. x 1/2" long x 41/64" i.d. Then install an ordinary
zinc-plated 5/8" i.d. split lockwasher between the pressure plates, dead
center of the clutch disc(es). The order of installing the clutch parts goes
like this: it's pressure plate, lockwasher, pressure plate, spacer, throw-out
bearing and then pressure spring. The lockwasher does two things - it acts
like a spring, which forces the pressure plates apart, it provides smooth
clutch engagement and it'll help to prevent the possibility of the clutch
disc from "grabbing" upon take-off. In addition, the spring-like action of
the lockwasher will expand the pressure plates when the clutch/brake pedal
is fully depressed so they will release from the clutch disc. Doing this
will guarantee that the clutch will engage smoothly and release every time.
So when reassembling a clutch assembly, don't install the cushion/teaser
spring. Instead, install the spacer and lockwasher as described above. You'll
be glad you did.
NOTE: If you're using an OEM fiber clutch disc or an aluminum clutch disc with an OEM pressure spring, then there's no need for the lockwasher and steel spacer. Just install the teasing spring and the clutch will engage smoothly without slipping.
NOTE: With the clutch fully engaged, sometimes air will get trapped between the pressure plates, which will at times create a vacuum seal and the clutch won't want to release easily. To keep this from happening, drill a 3/16" hole through one of the pressure plates close to the center so air can be relieved from within the center of the clutch disc.
How to Fix a "Sticking" Cub Cadet Clutch (when it won't release) -
Before reassembling the clutch, apply a light film of grease on the driveshaft where the rear pressure plate slides back and forth. If this was already done, and it still won't release, an ordinary 5/8" split lockwasher (made of zinc plated steel) may need to be installed between the pressure plates to spread (or force) them apart when the clutch pedal is depressed. Also, while the rear pressure plate off the driveshaft, make sure it doesn't bind on the shaft or on the roll pin. If it does, smooth the driveshaft or widen the roll pin slot slightly with a file. And it'll be a good idea to drill a small hole near the center of the pressure plates to relieve the air that gets trapped between the pressure plates.
Advertisement:
 If you need a 5/8" split
lockwasher and a steel spacer to replace the teasing spring, please contact
me, Brian Miller, at A-1 Miller's Small Engine &
Specialty Shop (1501 West Old Plank Rd., Columbia, Missouri. 65203 |
Phone: 1-573-875-4033). Please call any day between 12 noon and 8:00 p.m.
Central time, and please be patient because I stutter. Fax: 1-573-449-7347.
You can also contact me through Yahoo! Messenger:
|
If the 3/8" diameter OEM support pin that goes through the
clutch release lever is worn, this part should be replaced with an angled
pin. What wears the OEM pin (and release lever and bracket holes) is because
the pin is round. If the clutch parts are out of balance, or even slightly
out of balance, and as the engine runs with the clutch fully engaged, engine
vibrations causes the pin to spin in the bracket and lever, causing the pin
itself and bracket holes to wear. By replacing the round pin with an "L"
shaped angled pin, it can't spin. Therefore, the parts will last longer and
the clutch adjustment will remain the same for a longer time. (I think
IH Cub Cadet should have originally installed an angled pin in their tractors.
But then again, they probably didn't plan on their tractors being in use
30-40 years later.)
Advertisement:
| If you need a 3/8" diameter
"L" shaped angled support pin for the clutch release lever, please contact
me, Brian Miller, at A-1 Miller's Small Engine &
Specialty Shop (1501 West Old Plank Rd., Columbia, Missouri. 65203 |
Phone: 1-573-875-4033). Please call any day between 12 noon and 8:00 p.m.
Central time, and please be patient because I stutter. Fax: 1-573-449-7347.
You can also contact me through Yahoo! Messenger:
|
Saving a Used Throw-Out (Clutch Release) Bearing -
If
a used throw-out bearing is still pretty much "tight," but sounds noisy or
"rattles" when you spin it by hand, it could be saved from further wear by
pumping it full of automotive chassis lube. The same can be done to a new
bearing to insure that it will last a long time. (I've done this many
times when I rebuild clutch assemblies and have never had one complaint!)
The fresh grease will help keep the balls within the bearing lubricated and
cool, preventing them from further wear. But if the bearing is badly worn
or if you're in doubt about doing this, install a new one. (Cub Cadet part
# 741-3056)
When assembling the clutch components, never install the throw-out bearing
on the driveshaft backwards! Install it with the collar (the center part
that sticks out) towards the clutch disc.
How To Save A Used Throw-Out Bearing:
-
Drill a 3/32" hole in the grease/dust seal on the back side of the bearing.
- Wash the entire bearing in cleaning solvent until the rollers are free of the drill cuttings and dirt on the inside. It's clean when the sound changes when it's spun by hand and when it spins more freely.
- Use compressed air to blow dry the entire bearing, including the inside. But don't spin the bearing with the air! Doing this could further damage the bearing!
- Using either a chainsaw bar tip grease gun or a needle grease injector (resembles a hypodermic syringe) that attaches to a grease gun, pump the bearing through the drilled hole until it's full of grease. Turn the bearing 180º and pump it again. It's full when the grease starts to ooze out of the dust seals.
- Wipe the grease from around the hole with a clean rag and apply a dab of RTV adhesive silicone sealer (clear color) over the hole. The bearing is now good for another 10,000 miles!
The same procedure above can be done to many types of used precision, high-speed sealed roller bearings, besides just throw-out bearings. And for anyone who's ever wondered about this, when the clutch/brake pedal is fully depressed, the throw-out bearing moves back 3/8" on the driveshaft.
By the way - the throw-out bearing used in the model 582 is different than other models. It's an ordinary sealed high speed ball bearing with a sleeve pressed into it. It measures .780" i.d. x 1.850" o.d. x .550" wide. The number is 6204R5 and 180204. These are not Timken numbers. They will need to be cross-referenced.
Always install a pedal return spring, rather you think your tractor
needs one or not.
Don't
just install a cotter pin in place of it. A short, stiff, expansion spring
with a hook on each end off an old suspension-bed frame works perfect as
a pedal return spring. The size is approximately 3/4" diameter x 2-1/8" in
overall length.
There are no adjustments for the pedal return spring. It's job is to prevent the release lever from making connect with a throw-out bearing when the clutch pedal is fully disengaged. The pedal return spring attaches from the adjusting rod that runs from the release lever back to the bell crank that's on the clutch/brake pedal shaft. This shaft goes crossways through the frame of the tractor. It is very important that the tractor have a pedal return spring to prevent wearing of the throw-out bearing against the release lever (it will wear, too) while the clutch pedal is fully disengaged and the tractor is in operation.
If a pedal return spring is not installed or if the operator "rides the clutch" when pulling or when the tractor is in operation (keeping one's foot on the clutch pedal at all times), this will cause the throw-out bearing to spin the same speed as the engine, wearing it out prematurely. This will also wear the release lever as well. So making the proper adjustment and not "riding the clutch" will help the throw-out bearing last a very long time. The return spring connects from the hole in the end of the adjusting rod to a hole in the crossmember in the tractor's frame. NOTE: It may be somewhat difficult to get the end of the spring in the hole because of the tension, but it can be done, and it must be done. (I do it all the time with my Vise Grips and a little leverage from my trusty small prybar.)
No part of the release lever should make contact with the throw-out bearing when the clutch is fully engaged. If it does, and with the engine running, the driveshaft will spin the throw-out bearing, causing it to wear prematurely. In other words, the throw-out bearing will turn the same rpm as the engine. Therefore, there must be approximately .050" of clearance between the release lever & throw-out bearing. To determine this distance, adjust the nut on the adjusting rod that's on the release lever until there's about 9/32" of clearance between the pedal arm & pedal stop. And if your tractor doesn't already have one, definitely install a spring on the adjusting rod to the crossmember that's between the frame rails so the pressure will be taken off the bearing. Return To Previous Paragraph
Advertisement:
| If
you need a pedal return spring, please contact me, Brian Miller, at
A-1 Miller's Small Engine & Specialty Shop
(1501 West Old Plank Rd., Columbia, Missouri. 65203 | Phone: 1-573-875-4033).
Please call any day between 12 noon and 8:00 p.m. Central time, and please
be patient because I stutter. Fax: 1-573-449-7347. You can also contact me
through Yahoo! Messenger:
|
Information About the Pressure Spring -
If a light-weight tractor with a governed engine (up to 4,000 rpm) is going to compete in the stock class(es), it's okay to use the stock OEM Cub Cadet pressure spring with the aluminum clutch disc or possibly the OEM fiber clutch disc. A good used stock OEM pressure spring and a new OEM spring should measure no less than 6-1/2" in uncompressed length. The compressed length is 5". If a spring has been used on a driveshaft with an overheated or burned-out throw-out bearing, it's best to replace it. And if the pressure plates have been resurfaced (IMPORTANT: When resurfacing the pressure plates, and to insure true flatness, use a lathe that's in good condition with very little wear on the ways!), but the clutch still slips in the heavier classes with a stock spring, a 3/4" long steel spacer can be installed so the stock spring will apply more pressure or perhaps a cultivator spring kit may need to be installed.
For the pressure plates to grip the clutch disc(s) firmly, the pressure spring must be a stout one. The Cub Cadet pressure spring has about 250 psi of pressure and will probably not hold well in a pulling tractor. Therefore, a field cultivator spring, made by New Holland (part # PECP1511A1) or AGCO (part # EP1511) that's available at some farm implement dealers works excellent with the aluminum disc or double OEM clutches. This spring measures 7/8" i.d. x 1-3/8" o.d. x 14" long. It will need to be cut in half, with the cut end squared up. A sleeve, made of 41/64" i.d. x 7/8" o.d. x 4-1/4" long steel tubing must be placed in the center of the spring to prevent out-of-balance wobble. Don't use PCV, plastic or aluminum tubing. The spring will wear anything that's softer than steel. A large flat washer will need to be used on each end of the spring, too. The other half of the spring can be used for another clutch assembly. Each half of the cultivator spring has about a 500 psi rating, which is more than enough for use with an aluminum disc or double OEM clutches. (Meaning if the pressure plates are machined and trued up correctly, an aluminum disc or the double clutches won't slip with the cultivator spring.) Also, the cultivator spring isn't large enough in the outside diameter to interfere with the steering box. And the tension of the cultivator spring is easy on the clutch adjusting rod/linkage and your leg muscles! It's ideal for small kids to use. Return To Previous Paragraph
Advertisement:
 If you're thinking of
using a cultivator spring kit for your Cub Cadet clutch, please contact me,
Brian Miller, at A-1 Miller's Small Engine & Specialty
Shop (1501 West Old Plank Rd., Columbia, Missouri. 65203 | Phone:
1-573-875-4033). Please call any day between 12 noon and 8:00 p.m. Central
time, and please be patient because I stutter. Fax: 1-573-449-7347. You can
also contact me through Yahoo! Messenger:
New cultivator spring kit. 7" long x 1-3/8" o.d. x 7/8" i.d. $25.00 each, plus shipping. Used OEM Cub Cadet pressure springs. - $3.00 each. (Not recommended for pulling.) |
Use ALUMINUM as Clutch Disc Material!
NOTE: If an aluminum clutch disc is used in a high rpm tractor, I found they won't work as well because after a while the aluminum will get galled, and the clutch could become "grabby." The aluminum disc works better in a stock tractor with the engine running at a maximum of 4,000 rpms. Therefore, a double fiber clutch disc set up with a cultivator pressure spring may to be installed.
Instead of using a single OEM fiber material clutch disc, what one could do to prevent clutch slippage (and to save some weight from using a double clutch disc setup) is to fabricate and install a single piece of medium hardness (6061 alloy) or harder machined aluminum to serve as a clutch disc. With resurfaced pressure plates (IMPORTANT: When resurfacing the pressure plates, and to insure true flatness, use a lathe that's in good condition with very little wear on the ways!) and perhaps a stiffer pressure spring, aluminum should grip and hold up well even when used in a 50+ c.i. garden pulling tractor. When acquiring some aluminum, make sure that it's perfectly flat. Because if it's bent or warped, even slightly, it won't work. And when having a metal supply store cut off a piece of aluminum for you, tell them that you want it saw cut, and not sheared, chopped or sliced off. Because chopping aluminum will warp it, rendering the piece useless as clutch material. By the way, the OEM sandwiched steel fiber clutch disc and an aluminum clutch disc weighs almost the same; about 10.6 ounces each.
The aluminum clutch disc works best for low rpm stock engines. I use the aluminum clutch disc in my stock pulling tractors and the double OEM-fiber clutches in my higher horsepower tractors. I haven't had any problems with my clutches.
Fabricate the aluminum piece in a metal lathe (with a 3-jaw self-centering
scroll chuck). (See below Ê for instructions
on how to do this Ê) Make it the
same dimensions as the OEM clutch disc, except make the center hole 1-1/8"
to clear the 5/8" i.d. split lockwasher. This is a direct replacement for
Cub Cadet's OEM fiber clutch disc. If you don't have an OEM clutch disc to
measure or copy the pattern off of, the dimensions are as follows:
- Thickness is 1/4".
- Overall diameter is 6".
- Center hole is minimum 1-1/8"
- Bolt circle diameter for the three holes is 5-1/8".
Because a single, lightweight aluminum clutch disc is used, there's no need to install three extra studs in the 3-pin drive plate (see below Ê). But definitely have both pressure plates resurfaced as described above. IMPORTANT: When resurfacing the pressure plates, and to insure true flatness, use a lathe that's in good condition with very little wear on the ways! Depending on the size of engine and weight of tractor, the aluminum clutch disc requires a tougher driveshaft along with perhaps a cultivator spring kit. Or, in a stock tractor, you could get by using the OEM pressure spring. And install a center support bearing to prevent driveshaft wobble above 4,000 rpm. Also, if the pressure plates are properly resurfaced and if medium grade hardness aluminum is used, the aluminum won't excessively wear or melt onto them. If harder material (7071) aluminum is used, it's best to use a stiffer pressure spring, like the 800 lb. one that various aftermarket garden pulling tractor dealers sell.
There's two ways to make an aluminum clutch disc. Either use a 3-pin drive plate as a fixture to drill the holes into the aluminum, or machine an aluminum plate in a metal lathe (with a 3-jaw self-centering scroll chuck) and then with a vertical milling machine.
Here's one way to make an aluminum clutch disc:
- Acquire a square piece of perfectly flat 6" x 6" x 1/4" medium hardness (6061 alloy) or harder aluminum plate. Cut off the corners to get it as round as possible for less machining in the lathe. Use an OEM clutch disc as a templet.
- Temporarily remove the roll-pins from an OEM 3-pin clutch drive plate.
- Center the drive plate on top of the aluminum plate and using a drill press, drill three 3/8" holes through the aluminum so they'll perfectly match the roll-pin holes that's in the drive plate.
- After the drilling the holes, fasten the aluminum onto the drive plate using three 1-1/2" long x 3/8" diameter bolts. For perfect alignment, the unthreaded portion of each bolt must have contact with the aluminum.
- Chuck the hub of the drive plate in a metal lathe (with a 3-jaw self-centering scroll chuck) and machine the aluminum until it's perfectly round.
- With the drive plate still in the lathe, bore or drill a 1-1/8" hole in the center of the aluminum for the 5/8" lockwasher. Afterwards, remove the assembly from the lathe.
- Reinstall the roll-pins in the drive plate.
- Enlarge the holes in the aluminum disc to 13/32" for a "loose fit" on the 3 roll-pins in the drive plate.
- Fit the aluminum disc unto the roll-pins to check if it has a "loose" fit without binding.
Here's an alternative method how to make an aluminum clutch disc:
- Acquire a square piece of perfectly flat 6" x 6" x 1/4" medium hardness (6061 alloy) or harder aluminum plate. Cut off the corners to get it as round as possible for less machining in the lathe. Use an OEM clutch disc as a templet.
- Drill a 1-1/8" hole in the center.
- Chuck the center hole of the plate in a metal lathe that has a small, 4" diameter, 3-jaw self-centering scroll chuck.
- Machine the plate until it's perfectly round.
- Remove the aluminum disc from the lathe and clamp it in a super spacer or indexing fixture with a 3-jaw self-centering scroll chuck that's fastened on the table of a vertical milling machine.
- Drill 3 (or 6) 3/8" diameter holes at a 2.5625" radius exactly 120º apart for 3 drive pins and 60º apart for 6 drive pins. For precision accuracy, precision balance of the rotating parts and for safety purposes, with the plate (or center hub) clamped in a super spacer or indexing fixture (with a 3-jaw self-centering scroll chuck) that's fastened on the table of a vertical milling machine, the clutch pin holes must be drilled initially with a center or spotting drill (to prevent skating) exactly 120º apart for 3 drive pins and 60º apart for 6 drive pins at a 2.5625" radius. See chart above for the 3-pin drive plate.
- Enlarge the holes to 13/32" for a "loose fit" on the 3 roll-pins in the drive plate.
That's it! You now have a precision made, wobble-free machined aluminum clutch disc!
The biggest mistake a puller can make when launching a tractor is letting
the clutch out all of a sudden with the engine revved up. So when using aluminum
as a clutch disc (or any metallic clutch material), and when the tractor
is hooked to the sled, always remember to "slip" the clutch upon take-off.
To do this, first rev up the engine (a lot), and then slowly ease out
on the clutch pedal. Because an aluminum clutch disc may not "slip" at
low rpms, and because aluminum adheres to steel very well when under pressure,
if the pedal is let out all of a sudden with the engine revved up, and if
the tires don't spin, something could break or get damaged in the drivetrain
or transaxle. The 5/8" lockwasher that's placed between the pressure plates
will aide greatly in smooth clutch engagement/release and it lessens the
possibility of the clutch from "grabbing" upon take-off.
Advertisement:
| If you're thinking of using aluminum as clutch disc material for pulling
competition, heavy towing, garden plowing, pushing snow or just yard work,
please contact me, Brian Miller, at A-1 Miller's Small
Engine & Specialty Shop (1501 West Old Plank Rd., Columbia, Missouri.
65203 | Phone: 1-573-875-4033). Please call any day between 12 noon and 8:00
p.m. Central time, and please be patient because I stutter. Fax: 1-573-449-7347.
You can also contact me through Yahoo! Messenger:
And the lockwasher and steel spacer requires that a stiffer pressure spring, such as the cultivator spring kit, to be used so the lockwasher will collapse enough so the clutch will grip better. The lockwasher don't work well with Cub Cadet's OEM pressure spring. 6-1/2" diameter, 6-hole version of the above to replace the 4-puck metallic clutch disc (3/8" thickness) - $35.00 each, plus shipping. Or if you need your clutch assembly rebuilt or need some clutch parts as described in this web site, please contact me, Brian Miller, at: A-1 Miller's Small Engine & Specialty Shop (1501 West Old Plank Rd., Columbia, Missouri. 65203 | Phone: 1-573-875-4033). Please call any day between 12 noon and 8:00 p.m. Central time, and please be patient because I stutter. Fax: 1-573-449-7347. You can also contact me through Yahoo! Messenger:
The total for the single aluminum clutch setup listed above plus my labor is approximately $239.00, plus shipping. This price includes reusing some of your clutch parts. If I supply all of the parts, the price will be $324.00, plus shipping.
The total for the double clutch parts listed above plus my labor is approximately $300.00, plus shipping. This price includes reusing some of your clutch parts. If I supply all of the parts and labor, the price will be $385.00, plus shipping. |
New (6061 alloy; medium-grade
hardness) machined aluminum clutch disc kit with (3) 13/32" holes for the
3-pin drive plate. This is a direct replacement for Cub Cadet's OEM fiber
clutch disc. Comes with 6 holes and can be used with either a 3- or 6-pin
drive plate. Made of the highest quality aluminum available. The disc is
turned in my metal lathe and then the holes are precision-drilled in a super
spacer on my milling machine. Each aluminum clutch disc comes with a 5/8"
i.d. split lockwasher and a steel spacer to replace the cushion/teaser
spring. $35.00 each, plus shipping.
IMPORTANT - Both pressure plates MUST be resurfaced
(machined flat in a metal lathe) before using the aluminum clutch disc, or
severe slippage may result!
Fabricating a Double OEM Clutch Disc Setup -
This type of clutch setup has been in use for many years. It's been proven to hold very well even with a highly modified engine. So if you wish to install two OEM clutch discs (fiber material w/sandwiched steel) instead of using a single aluminum clutch, here are the details and items that are needed:
ü 5/8" diameter hardened steel [driveshaft] material (as mentioned earlier in this web page), cut to the exact length of the original shaft. The driveshaft in the early and later model Cub Cadets come in different lengths - 18-3/16" for the narrow frames and 19-3/16" for the wide and spread frames.
ü Two OEM Cub Cadet clutch discs. (Cub Cadet part # 761-3002)
ü
A
machined 1/8" thickness x 4-5/8" diameter steel plate with a 5/8"
diameter hole drilled in the exact center. This piece resembles a large
flat washer. See drawing. à
ü One half of a cultivator spring (with an inside spacer and two flat washers, as explained earlier in this web page È), for use as a pressure spring. Be aware if you choose to use the OEM pressure spring for pulling. It may not be strong enough (for your particular tractor) to keep the clutches from slipping.
ü
Two
1/4" diameter x 1-1/2" long grade 5 bolts
with lock nuts. These two 1/4" bolts lets the outer pressure plates drive
the center plate. They go through all 3 plates. The unthreaded portion of
each bolt must have contact with the center plate and both pressure plates,
for longer wear and a stronger hold.
ü Six 3/8" diameter x 3" long grade 5 or grade 8 bolts with matching nuts, lockwashers and flat washers. Or you can purchase a heavy duty, 1/4" thick 6-pin drive plate from me, Brian Miller. I fabricate and sell them for $60.00 each (plus shipping). Click here for more information.
ü
A 5/8" i.d. pillow block bearing with a cast iron housing for use as a center
support for the driveshaft. Don't use one with a stamped steel housing.
The housing will break due to normal vibration.
ü 
A
brace to mount the pillow block bearing to. Made of minimum 1/8" thickness,
1-1/2" x 1-1/2" x 10-1/4" long piece of angled steel. Dimensions of the brace
and where to drill the holes are in the drawing to the right.
Important! Before installing this brace in the tractor's frame,
first install the driveshaft with it connected to the transaxle, and then
bolt in the engine. This will guarantee that the pillow block bearing is
perfectly aligned (centered) with the driveshaft. And then weld or securely
fasten the brace to the frame. On the narrow frame Cub Cadets, the brace
installs from underneath the tractor. With the driveshaft in place and engine
installed and bolted down, hoist the front end of the tractor up and weld
the brace the frame rails.
Advertisement:
| If you need a pillow block bearing and a brace to mount the pillow
block bearing onto, please contact me, Brian Miller, at
A-1 Miller's Small Engine & Specialty Shop
(1501 West Old Plank Rd., Columbia, Missouri. 65203 | Phone: 1-573-875-4033).
Please call any day between 12 noon and 8:00 p.m. Central time, and please
be patient because I stutter. Fax: 1-573-449-7347. You can also contact me
through Yahoo! Messenger:
Vibrations from the engine travels through the driveshaft, causing it to "whip around" and possibly break at high rpms. That's why a center support bearing and brace is needed on the driveshaft.
|
ü A piece of 41/64" i.d. x 7/8" o.d. x 1/2" long steel tubing to replace the teasing/cushion spring.
ü Two ordinary zinc plated 5/8" i.d. split lockwashers. Don't use stainless steel or grade 8 lockwashers. They're too stiff for this purpose and won't compress as easily. It doesn't require much force to spread the pressure plates apart.
There are 4 steps in Fabricating a Double-Disc Clutch Setup
Step #1 - "Notch" the Release Lever and Relocate it's Bracket:
There are two options of doing this. Either way you choose to do it, you
will need to make room for the extra clutch disc and center drive plate.
Option #1:
Only on the narrow frame Cub Cadet, cut out the lower part of the clutch release lever so it'll clear the steering box, when the clutch/brake pedal is fully depressed.
- Remove the clutch adjusting rod and cut 3/8" off the threaded end. If this is not done, the rod will be too long and interfere with the rear clutch friction disc.
- Relocate the bracket that the release lever is connected to rearward 3/8". Or for a very stiff pressure spring, use a piece of minimum 3/16" thickness angled steel to fasten the bracket onto, and then weld the angled steel to the frame. Be sure the angled steel is located 3/8" further back than the original bracket was.
- Only on the narrow frame Cub Cadet, cut out a place in the frame so the release lever will clear it when the clutch/brake pedal is fully depressed.
- NOTE: The steel spacer that replaces the teasing spring can't be left out for double clutches because the longer studs (cut-off bolts) in the drive plate would hit the release lever when the clutch is engaged.
Option #2:
Instead of relocating the bracket and notching the lever, the engine mounting holes that's in the frame can be welded up, grind the weld flat and then drill some new holes exactly 3/8" forward (toward the front of the tractor) from the original holes. You'll also need a longer driveshaft, 3/8" longer to be exact. And you'll need to drill the #1 hole forward 3/8" and then drill the other holes same as in the original driveshaft.When using a deep sump oil pan, with the front axle in the stock position and when moving the engine forward, the axle pivot pin would interfere with the pan. For pulling competitively, the front axle would need to be moved as far forward as it'll go for better weight distribution. But if your club's rules don't allow the front axle to be moved forward, then a flat bottom oil pan can be used, and then the engine can be moved forward with no problems. Of course, half of the dipper on the connecting rod would need to be cut off, too.
Either the engine can be moved forward or the bracket moved rearward. Either way, one or the other will need to be relocated to accommodate for the extra clutch disc and center plate, and so the clutch will function properly.
Step #2 - Converting the "3-Pin" Clutch Drive Plate into a 6-Pin:
- Cut the heads off the 3/8" bolts. Bevel or smooth the cut ends.
- Remove the roll-pins from the 3-pin drive plate.
- Make exact measurements and then drill one (or two) new [3/8" diameter] holes between each original hole that's already in the plate. There will be six or nine (nine studs has more holding power) holes altogether. For precision, the holes should be drilled with the plate clamped in a super spacer or indexing fixture (with a 3-jaw self-centering scroll chuck) (if clamping the outer edge of the plate, be sure to true it up in a lathe [(with a 3-jaw self-centering scroll chuck)] first), that's fastened on the table of a vertical milling machine. Or you can purchase a heavy duty, 3/16" thick 3- or 6-pin drive plate from me, Brian Miller. Click here for more information.
- Drill new holes in the clutch discs to match all the holes in the drive plate. Again, for precision, the holes should be drilled initially with a center drill to prevent skating with each disc clamped in a super spacer or indexing fixture with a 3-jaw self-centering scroll chuck that's fastened on the table of a vertical milling machine.
- Install the 3/8" bolts, lockwashers, flat washers and nuts in the modified drive plate. Install the flat washers under the nuts on the back side of the plate and on both sides of the drilled out holes to help distribute the pressure of each bolt/stud in the plate.
- Check to see if the clutch discs fit onto the studs that's in the drive plate. They must match perfectly. But the clutches might fit tight because of the 3/8" studs and 3/8" holes.
- With the clutch discs fastened onto the drive plate, true up the outer edge of the drive plate and clutch discs in a metal lathe (with a 3-jaw self-centering scroll chuck). This is very important for precision balance and durability!
- Enlarge the holes in the clutch discs to 13/32" so they'll slide on the studs without binding.
Step #3 - Drilling Holes in the New Driveshaft:
- Remove everything from the old driveshaft.
- Lay the original shaft along side the new one. NOTE: If you have a tractor with no driveshaft and want to know the measurements of where the holes are to be drilled, click here or scroll up. È
-
Use a felt tip or paint marker to place a mark on the new shaft where the
#1 and #4 holes are in the original shaft. And then mark the #2 and #3 holes
exactly 3/8" further down on the new shaft in relation to where the
#2 and #3 holes are in the old shaft.
-
Drill
the holes in the shaft for the roll-pins. Or install a split locking collar
instead of drilling the 3rd hole. IMPORTANT!
click here
or scroll up È for details on the
correct way of drilling the holes for the roll-pins in the driveshaft. And
use only the OEM-quality coiled or spiral roll-pins! Because an ordinary
spring-type roll-pin may break. Click
here if you need to purchase some new coiled or spiral roll-pins.
Step #4 - Drilling Holes in the Pressure Plates and Center Plate:
- Place the 1/8" center plate between the two pressure plates with the center holes aligned. (Use a 5/8" diameter bolt to fasten all 3 plates together for drilling the two holes.) And check to make sure that the roll-pin hole and slot that's in the hubs are properly aligned!
- Mark where the two holes are to be drilled 2-1/2" apart and then drill each 9/32" hole in all three pressure plates at the same time, 90º in relation to the roll-pin holes and slots that's in the pressure plate hubs. This is so the two 1/4" bolts won't interfere with the installation or removal of the roll-pins in the driveshaft. Also, drilling 9/32" holes in the plates will allow the bolts to be loose enough so the plates can slide freely on the shaft without binding.
- Install a spiral-type roll-pin in the #3 hole in the shaft or install a split locking collar. Apply a thin coat of grease (automotive chassis lube) on the driveshaft (so the rear pressure plate and throw-out bearing can slide back and forth easily), and then install the large 5/8" i.d. flat washer, inner spacer tubing, pressure spring, the other large 5/8" i.d. flat washer, throw-out bearing, and then use the steel spacer to replace the teasing/cushion spring. IMPORTANT: But don't be too generous with the grease on the driveshaft! Some of it could sling off onto the pressure plates and clutch disc when the tractor is in operation, causing severe clutch slippage!
-
This step can be complicated and somewhat dangerous.
So be very careful when doing this because the pressure spring is under a
lot of tension!
Using
a typical hydraulic press, place the driveshaft front-end down in the press.
With the release lever laying across the lower beams, compress the pressure
spring, throw-out bearing and spacer, then slip a 1/4" diameter bolt in the
#2 hole in the shaft. Remove the shaft from the press.
- With the [front] end of the shaft clamped firmly in a soft-jaw bench vise (a couple of soft aluminum angle pieces when placed in the vise jaws works ideal to prevent marring the driveshaft), using a heavy brass hammer, drive the rear of the driveshaft forward to release the 1/4" bolt, and replace the bolt with the roll-pin in this hole. Remove the driveshaft from the vise and install the clutch release lever.
- Apply a thin coat of grease (automotive chassis lube) on the driveshaft (so the center plate, rear pressure plate and throw-out bearing can slide back and forth easily) and slide the pressure plates, center plate, 5/8" lockwashers and the two clutch discs on the driveshaft in their respective order. And then install the two 1/4" bolts in the pressure plates and center plate. IMPORTANT: But don't be too generous with the grease on the driveshaft! Some of it could sling off onto the pressure plates and clutch disc when the tractor is in operation, causing severe clutch slippage!
- Again, clamp the [front] end of the driveshaft firmly in the soft-jaw bench vise. And again, using a heavy brass hammer, drive the rear of the driveshaft forward so the roll-pin holes will be aligned with the hub in the front pressure plate and install the roll-pin in the #1 hole. Remove the driveshaft from the vise.
- Slide the pillow block bearing from the rear of the shaft and position it next to the 3rd roll-pin (or split locking collar). Because that's the closest you're going to get to the center of the driveshaft. Now install the rear coupler on the driveshaft using a spiral-type roll-pin.
- Install the assembled unit and the engine in the tractor. (The engine must be fastened down in the tractor for correct driveshaft alignment so the bearing in the pillow block will be properly centered with the crankshaft and the transaxle input shaft.)
-
Mount
the pillow block bearing on the angle steel brace. Before this brace is
welded to the tractor's frame, first install the driveshaft with it connected
to the transaxle, and then bolt in the engine. This will guarantee that the
pillow block bearing is perfectly aligned (centered) with the driveshaft.
And then weld the brace to the frame.
- After the pillow block bearing and angle steel brace are securely fastened in place, remove the engine and remove the 6-pin drive plate from the engine and then slide the 6-pin drive plate onto the clutches. Place the transaxle in gear. Depress the clutch pedal by hand, and at the same time turn the drive plate by hand to make sure that the clutches release and turn freely. If they don't, remove the clutch assembly and make adjustments as necessary. By the way - the 5/8" split lockwashers will hold the clutches kind of tight at first, but will lose some tension somewhat overtime.
- If the clutches do release freely, fasten the drive plate onto the engine and place a small amount of automotive chassis lube (grease) in the pilot bushing.
-
Use
a hardened 1/4" diameter [grade 8 or an
Allen head] bolt to fasten in the rear hole of the coupler where it connects
to the input shaft on the transaxle. Installing a bolt instead of a roll-pin
here makes it much easier to remove the driveshaft assembly in the future
if you ever need to. For the other holes in the driveshaft, use only spiral-type
roll-pins. Acquire a bolt with the length of the unthreaded portion (shouldered
part) the same length as the coupler, with the unthreaded portion having
contact with the coupler and shaft, for longer wear and a stronger hold.
And use an ordinary split lockwasher and nut to secure it in place.
NOTE: If the transaxle has been moved to the end of the
frame for improved weight distribution, instead
of making a new, longer driveshaft, you can use the present one by fabricating
an extended coupler made of .626" i.d. x 9" long heavy wall steel tubing.
Run the tubing about 1" up on the driveshaft for stability. The brake linkage
and shift lever will also need to be lengthened. And unless you have very
long legs, leave the operator's seat and fenders in their present
position.
-
Install
the pedal return spring to keep from wearing
out both the throw-out bearing and release lever. An extension spring from
an old bed frame with a hook on each end works ideal for this purpose. And
remember to never "ride the clutch." This means keep your foot off the clutch
pedal when pulling or operating the tractor. The return spring connects from
the hole in the end of the adjusting rod to a hole in the crossmember in
the tractor's frame. NOTE: It may be kind of hard to get the end of the
spring in the hole because of the tension, but it can be done. (I do it all
the time with my Vise Grips and a little leverage from my trusty small
prybar.)
- Finally, make the necessary clutch adjustment, which is supposed to be .050" clearance between the throw-out bearing and release arm. To set this clearance, turn the nut on adjusting rod so the clearance between the pedal stop and the clutch/brake pedal has 9/32" of clearance. And make sure that a small expansion spring is installed from the end of the adjusting rod to the hole in the cross member that's welded to the frame. This moves the release lever away from the throw-out bearing when the clutch is fully engaged so neither will wear. And adjustment of the clutch may have to be checked from time to time as parts wear.
NOTE: If your engine is so powerful that the single aluminum disc or the double OEM clutch setup slips, with a cultivator spring, then perhaps installing a stiffer pressure spring from Lakota Racing (http://www.lakotaracing.com/), Midwest Super Cub (http://www.midwestsupercub.net/), Nichols Performance (http://nicholsperformance-online.com) or Vogel Manufacturing Co. (http://www.vogelmanufacturing.com/) would help for superior holding power.
Using a Volkswagen Clutch Assembly in a Cub Cadet -
The third type of clutch that some pullers use is a Volkswagen clutch assembly (starter, flywheel, clutch disc, pressure plate and throw-out bearing and release lever) adapted to the Kohler crankshaft with a special-made tapered hub adapter. This type of clutch is made for the 1974 VW's and earlier with the air-cooled engine. They weigh more than the double clutch assembly as described above (about 22 lbs. lighter, less hub) and they hold extremely well even in a highly modified (50+ c.i.) garden tractor. Also, the VW flywheel, starter ring gear and clutch assembly requires the VW starter. An adapter that replaces the Kohler-type flywheel must be fastened onto the crankshaft for the VW flywheel to work. And the starter must be adapted onto the Kohler engine block with a special bracket. Vogel's Machine has crankshaft hub adapters to install a VW flywheel/clutch assembly for use on a Kohler engine. The VW clutch comes in two sizes, 180mm and 200mm, with the 180mm being the choice for garden tractor pulling. This type of starter and clutch assembly is losing popularity with pullers who run the 50+ c.i. garden tractors because of it's excessive [forward] weight.
Improving International Harvester's "Original" Cub Cadet (belt-to-clutch-drive) Clutch Assembly - (Updated 11/24/08) Top of page
The first Cub Cadet model made was the International Cub Cadet tractor, better
known as the Original. On these type of tractors, the power from the engine
is transferred from a small pulley onto a larger pulley by use of a V belt,
which act like a gear reduction. It's approximately a 1.6:1 reduction. This
means that engine torque is increased 1.6 times to the driveshaft because
the clutch/driveshaft assembly turns 1.6 times slower than the engine.
If the clutch holds well, but won't release at times, this means the sliding parts on the driveshaft are dry or the old grease has accumulated dirt and/or has "dried up," causing the parts to bind on the driveshaft. To repair this...
- Remove the clutch assembly from the tractor.
- Disassemble it completely.
-
Clean the parts and before reassembling the clutch components, apply a thin
coat of grease (automotive chassis lube) bronze bushing in the pulley,
on the splined slider and on the driveshaft itself where the moving parts
slide back and forth.
Don't be too generous
with the grease on the driveshaft! As the driveshaft spins, some of the grease
could sling off onto the pressure plates and clutch facings when the tractor
is in operation, causing severe clutch slippage!
- Be sure to take note of how the parts are installed for reassembly or refer to [click on] the drawing below. î
But if the clutch slips, doing the following should cure the
problem:
First, resurface the pressure plates on a flat belt or large disc sander. If the clutch discs (which is part of the pulley) aren't worn excessively, they can be sanded flat as well to match the flatness of the pressure plates. Just remove the raised places, no more. But if the fiber material is worn thin or if you have doubts that it won't grip well, then install new clutch facings on the pulley.
If the clutch material "peels off" or comes loose from the pulley, it can be reattached with Super Glue or any high-strength glue. As soon as the fiber material is glued on the pulley, place the clutch/pulley assembly between two thick flat steel plates to cover the entire fiber material and then place them in a hydraulic press and apply light pressure to squeeze out any air bubbles that may get trapped so the fiber material will have a stronger bond and lay flat. After the glue has dried, lightly sand the fiber material on a large flat sanding disc or belt sander to insure true flatness.
As far as I'm aware of, new clutch fiber material is not available from any source. I was lucky once to find some material that matched the original perfectly. Of course, I had to do some trimming so they'll fit. (I have no more of this material left.) I then attached the material as described in the paragraph above.
For even better clutch adhesion or "holding power," the OEM pressure spring can be replaced with a cultivator spring kit. Be sure to drill the 3rd hole to 1/4" and install a heavy spiral roll pin, too! Install a new bronze bushing in the throw-out bearing if it's worn. Then lubricate the throw-out bearing through the factory-installed grease fitting. Under normal use, the throw-out bearing needs to be lubricated once a year.
To reassemble the Original clutch assembly, first of all, I use my 12 ton hydraulic press to compress the pressure spring on all of the clutch assemblies that I rebuild. For the Original clutch assembly, everything reinstalls in the reverse order of removal. I slide the splined carrier against the throw-out bearing collar and then place the driveshaft in my press and compress the spring until the carrier is aligned with the roll pin hole. Then I install the roll pin. Then to install the pressure plates and clutch disc/pulley, I place the front of the driveshaft in my bench vice (with a couple of soft aluminum angled pieces placed in the vice jaws, of course) and then I drive the driveshaft forward with a heavy brass hammer until the roll pin can be driven in place for the front pressure plate.
With the clutch fully engaged, air is trapped between the pressure plates, which will at times create a vacuum and the clutch doesn't want to release easily. So to keep this from happening, drill a small hole through the front pressure plate close to the center so air can be relieved from within the center of the clutch disc.
NOTE! Above 4,000 rpms, bronze bushings will not last long under side-thrust. Therefore, it'll be a good idea to install two high speed sealed ball bearings in the clutch disc/pulley assembly. See the picture below for a better understanding.
Advertisement:
 If you need two quality,
high speed sealed ball bearings installed in your Original pulley/clutch
disc, please contact me, Brian Miller, at A-1 Miller's
Small Engine & Specialty Shop (1501 West Old Plank Rd., Columbia,
Missouri. 65203 | Phone: 1-573-875-4033). Please call any day between 12
noon and 8:00 p.m. Central time, and please be patient because I stutter.
Fax: 1-573-449-7347. You can also contact me through Yahoo! Messenger:
|
By the way, the reason the above tractor is called the "Original" is because they're the very first Cub Cadet garden tractor that International Harvester produced. They didn't have a model number because they were all built basically the same. That's why most folks nowadays call them the "Original" Cub Cadet.
Are "V" belt drive garden tractors competitive pullers?
A "V" belt will rob an engine of power simply because it must "rub" in the pulleys due to friction. Because that's how it gets its grip to transmit power. If you were to place the transmission in neutral with the engine at a slow idle on a belt drive mower/garden tractor, then release the clutch pedal, you'll notice that the engine will slow down some. The tighter the belt, the slower the engine will idle. That's why V belts are noisy on some older automobiles. And that's also why auto manufacturers nowadays use a single serpentine belt to drive all the power accessories. Serpentine belts robs an engine of less power and it helps to get better fuel mileage. Direct drive Cub Cadets use no belts in the drive train. This means no power loss whatsoever.
Although sometimes a belt drive tractor will do very well in the stock class(es), they tend to lag behind in the higher horsepower class(es). But if you really like your V belt tractor and want to be a competitive puller in the higher horsepower classes, you'll have to adapt your V belt garden tractor fenders, hood, grill, etc., onto a Cub Cadet frame and drive train.
But if you do run a belt-driven garden tractor for pulling (that's obviously going to be used in a stock class), the things I can suggest to keep the drive belt from slipping are:
- Make sure that the belt and pulleys are in good condition. Make sure there's no deep grooves wore into the drive pulley (the one on the engine).
- Make sure all pulleys are properly aligned.
- Install a stiffer spring on the idler pulley to tighten the belt more than what the factory intended for.
- As a last resort, attach a long lever onto the clutch pedal, so the operator can pull back on it to help tighten the belt even more.
To speed up your tractor some, use a slightly larger pulley on the engine and/or a slightly smaller pulley on the rear end. To slow it down, just do the opposite. And you may have to use a different length belt. Actually, it's best to use a garden tractor that has a variable speed drive. And the only place that sells gears for a Peerless transaxle is a Tecumseh Engine dealer. And there are no special Peerless gears made for pulling. The only alternative is to change the diameter of the pulleys on the engine and transaxle to change the ground speed of the tractor.
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