Modifying the IH & Early MTD Cub Cadet Transaxles for Heavy Use and/or Pulling Applications

Part 1 - Gearing a Cub Cadet Pulling Tractor

The reason to use the right gearing in a pulling tractor is to match an engine's ability to give the tractor momentum so it can pull the sled a little further down the track without sacrificing horsepower or increasing/decreasing torque at the rear wheels. In other words, if one pulls in a particular gear that is too fast, they increase the ground speed, but run out of horsepower in the end. If they pull in a gear that's too slow, they have plenty of power, but don't have the needed ground speed, meaning they may run out of traction at the end. The point here is to obtain a correct "balance" between an engines' power output and torque at its rear tires, which should result in a good pull every time.

The factory-installed gears that originally came in IH Cub Cadet transaxles (a transaxle is a combination of a transmission and rear axle as one unit) are 13 tooth 1^st gear, 16, 17 or 19 tooth 2^nd gear and 26 tooth 3^rd gear. The "tooth" count are the number of teeth on each upper gear. The 16 tooth 2^nd came out in the early 1960's, while the 19 tooth replaced it in later years.
NOTE: The model 100's used a 16 tooth 2nd gear in serial numbers 65458 through 96765. After that they went to the 19 tooth second. And a Cub Cadet having a factory installed 17 tooth 2^nd gear is rather rare. To find the gear ratio, always divide the number of teeth on the lower gear by the number of teeth on the upper gear. The mating upper and lower gears together have a total of 52 teeth. There are no exceptions. For example: 2^nd speed has 19 teeth on the upper gear and 33 teeth on the lower gear to equal 52 teeth total (19 + 33 = 52). And 3^rd speed have two 26 tooth gears, resulting in a total of 52 teeth (26 + 26 = 52). And so forth. Factory stock OEM gear ratios are as follows:

• 1^st speed ratio is 3:1 (lower gear has 39 teeth, upper gear has 13 teeth... 39 ÷ 13 = 3:1)
• 2^nd speed ratio is either 2.25:1 for a 16 tooth (lower gear has 36 teeth, upper gear has 16 teeth... 36 ÷ 16 = 2.25); 2.06:1 for a 17 tooth (lower gear has 35 teeth, upper gear has 17 teeth...35 ÷ 17 = 2.06) and 1.74:1 for a 19 tooth (lower gear has 33 teeth, upper gear has 19 teeth... 33 ÷ 19 = 1.74)
• 3^rd speed ratio is always 1:1 (upper and lower gears have 26 teeth each... 26 ÷ 26 = 1)
• The gear ratio in the reduction housing of the DIRECT DRIVE MODELS is 7:1 (lower gear has 84 teeth, top gear has 12 teeth... 84 ÷ 12 = 7)
• The gear ratio in the reduction housing of the BELT DRIVE MODELS ("Original" Cub Cadet) is 4.4:1 (top gear has 57 teeth, lower gear has 13 teeth... 57 ÷ 13 = 4.4)
• The ring and pinion gears have a 4.6:1 ratio (ring gear has 46 teeth, pinion has 10 teeth... 46 ÷ 10 = 4.6)

The number of factors to take into consideration when choosing the right gearing for a garden pulling tractor are:

The references listed below are for a tractor having sharpened tire tread and a healthy engine without a governor. And the following statements are meant only as a reference. Because when it comes to pulling competition, nothing is really certain.

Rule of thumb in having the proper gear ratios are as follows:

• For an 8hp pure stock engine with 26x12.00-12 tires and 13" hitch height, one could get by using just 1^st gear. As for the 8hp tractors with 23x10.50-12 tires and a 10" hitch height, one could pull a stock 16 tooth 2^nd gear (upper gear teeth count). But could probably pull with a slightly faster gear with narrower tires.
• For a 10hp pure stock engine with 26x12.00-12 tires and 13" hitch height, one could pull all the time in 1^st gear (but there is a chance of damaging the engine due to high rpms, if running without a governor). Or, one could possibly pull a 14-16 tooth 2^nd & 3^rd gear set. If the tractor is running 23x10.50-12 tires and a 10" hitch height, one could just pull a stock 19 tooth 2^nd gear.
• The 900 lb. built to the max stock 10hp and under (GTPOMMA class) with 26x12.00-12 tires and 13" hitch height can pull a stock 13 tooth 1st gear with a 13 tooth overdrive pinion, and custom 14 tooth 2nd with 15 tooth 3rd gear. This combination of 3 forward pulling gears will be an equivalent of a 14 tooth 1st, 15 tooth 2nd and 16 tooth 3rd.
• For a 12hp stocker with 26x12.00-12 tires and a 13" hitch height, one could get by all the time with a stock 16 tooth 2^nd gear, or installing a 15-17 gear set could work, too. As for 23x10.50-12 tires and a 10" hitch height, one could pull a 17-19 gear set.
• For a 16hp stocker with 26x12.00-12 tires and a 13" hitch height, a 19 tooth 2nd gear would probably do just fine. Or, installing an 18-20 gear set could work also. If it has a set of 23x10.50-12 tires and a 10" hitch, it could pull a 22-24 gear set.
• The 950 lb. 30 c.i. (12hp Super-Stock; NQS class) with 26x12.00-12 tires and 13" hitch height can pull a 18, 19 (replaces 1^st & reverse gears), 20 and 21 (2^nd & 3^rd) tooth combination 4 speed gear set.
• The 1050 lb. 16hp (37 c.i.; Missouri Super-Stock) with 26x12.00-12 tires and 13" hitch height can use a 20, 21 (1^st & reverse), 22 and 23 (2^nd & 3^rd) tooth combination 4 speed gear set.
• The 1050 lb. 16hp NQS Modified (50+ c.i.) with 26x12.00-12 tires and 13" hitch height can use a 23, 24 (1^st & reverse), 25 and 26 (2^nd & 3^rd) tooth combination (2^nd & 3^rd ) 4 speed gear set.

Remember, there's about a 600 rpm difference (reduction or increase) in gearing between one set of gears with a particular number of teeth and another set of gears with one tooth more or one tooth less.

The reason for a combination 2^nd and 3^rd speed gear set is to slow down the tires in 2^nd gear when pulling on a biting track (moistened, sticky surface), which will provide more traction and reserve engine power, because the tires probably wouldn't be able to spin as easily. With a slightly faster 3^rd gear, (faster than 2^nd gear, but slower than factory-stock 3^rd gear), would perform better on a hard, dry or loose track (which will allow the tires to spin more easily), will provide more ground speed without sacrificing engine power. So having a double gear set is better than pulling in just one gear all the time, which is either too slow or too fast.

OR, the stock OEM 10 tooth pinion gear can be swapped out with an aftermarket 13 tooth pinion gear and the large OEM reduction gear can still be used. This will increase the drive gears about 1 tooth. If you want your tractor to go faster, then both the pinion and reduction gears must be changed. See picture è To replace the reduction shaft/gear (small pinion gear), first pry out the oil seal, then remove the snap ring and then drive the shaft out from the rear of the housing with a hammer and 1/2" round steel rod. Be careful not to damage the needle bearing. After you install the new shaft, apply a thin bead of clear RTV silicone adhesive/sealant to seal the bearing in the rear of the housing. Or, to remove a pinion and not destroy any parts (seal, etc.) use a "slide hammer" and put an angle or channel steel to use as a lever. Using this method, you do not damage even the most stubborn pinion. You can reuse everything and don't have to worry about any leaks. No machine work is required when installing overdrive gears. Just remove the small upper pinion gear and the large lower gear and install the aftermarket gears. And when reassembling a Cub Cadet gear drive transaxle, there's no need to install any gaskets. Just use a thin bead of clear RTV silicone adhesive/sealant. By eliminating gaskets, silicone sealer "strengthens" the transaxle housings by securely "bonding" them together or having them make positive metal-to-metal contact, which keeps the bolts securely tight, plus the silicone fills in any imperfections between the two metals, eliminating oil leaks. If you want more gearing, check this out: http://nicholsperformance-online.com/page28.htm.

The Cub Cadet "Creeper Drive Unit" -

The Cub Cadet "creeper drive unit" is a 2-speed selective high/low gearbox. It's a small gearbox that mounts on the front of the Cub Cadet transaxle. When the lever is placed in LOW position (reduction speed; 2:1 ratio), all the gears in the transaxle are reduced by half, which means the tractor will move half its speed. When the lever is placed in HIGH position (1:1 ratio), the gears in the transaxle turn their normal speeds. Creeper drives are required when mowing heavy grass, plowing a garden, pushing snow or hauling heavy loads up a steep hill, doing all this especially with a small engine. The creeper drive unit was optional equipment that was offered by Cub Cadet. You can find one on eBay, but it may need to be rebuilt.

If your tractor didn't come with a creeper drive unit and you want to install one, here's how to do it:

1. Remove the driveshaft assembly.
2. Install the small gear onto the input shaft on the transaxle with a spiral roll pin.
3. Fasten the creeper gearbox to the transaxle.
4. Shorten your driveshaft where the groove is, or there's no groove, cut 5-1/2" off the rear.
5. Install the coupler on the driveshaft and reinstall the driveshaft in reverse order of removal.
6. Go here to learn more: http://cubfaq.com/creeper.html.

Your best bet to acquire a creeper drive unit would be to look on eBay (under keyword Cub Cadet) or post a want ad in my web site: FREE Advertisement Posting Page. And remember, when you do acquire a creeper drive unit, first make sure it's in good condition, and that you receive the splined coupler and all the hardware with it.

Although ordinary motor oil can be used, it's best to use heavy gear oil (SAE 90) when filling the creeper unit for long life and less wear on the parts. Go here if you need part numbers for the creeper drive unit: Creeper Drive parts for the Cub Cadet model 100. NOTE: Due to their age, some parts are no longer available for these units!

If you're using either old or new gears, it's always a good idea to install a locking bracket on the chassis (tractor frame) to hold the shift lever in position when pulling. If pulling in 2^nd gear only, the bracket can be made of 1/8" x 1" flat steel, or just use an adjustable yoke end. For pulling in 2^nd and 3^rd speed gears, make the bracket of 1/4" x 1" flat steel. Use a single 3/8" bolt (stud size) to fasten the bracket to the chassis. Measure accurately before fabricating and permanently installing!

Sometimes while the tractor is still hooked to the sled just after a pull, the clutch(es) on a Cub Cadet will refuse to release (with the clutch pedal fully depressed, of course) and at the same time the puller tries to force the shift lever into the neutral position, this may cause the transmission gears to become locked up.

If this has happened to your tractor, to fix this, first, you'll need to remove the entire transaxle or just move it back enough so you can remove the shifter cover. After that, use a large flat screwdriver to shift the gears into the neutral position. (That's when the slots in the shift forks [where the shift lever ball end fits into] are aligned.) Then, use a small hammer to bring the shifter forks back together so the shifter ball will fit snugly into them. Due to worn gears and pulling force, these slots will sometimes flare out on their own.

To replace a broken shifter fork, you'll need to first remove the rod that it attaches to. To do so, you must remove the transaxle from the tractor, remove the front gear reduction housing, remove the rear end cover and then use a long drift to drive the rod forward from the transaxle case. Be sure to place a finger over the hole so the small steel ball and spring won't pop out and possibly get lost. Reassembly is in reverse order of removal.

To prevent the gears from locking up again, first, make sure that the slots are properly aligned and they're not flared out. Then place a bead of weld on each side of the shift forks as shown in the picture to the right or above so they won't spread out again. The weld will prevent the slots from spreading again and also keep the clamp bolts from loosening.

And in high-torque engine tractors, the mainshaft (upper shaft) could also become twisted, resulting in total lock up of all the gears. Contact True Gear and Spline, Inc. for quality hardened gears, shafts, ring gears and other Cub Cadet transaxle components.

If the transaxle jumps out of reverse as soon as it strains a little, this means that the shift forks are bent and need straightening and welding OR the most likely the teeth on the reverse idler gear are worn. They get worn because some people won't bring their tractor to a full stop before placing the transmission shifter into reverse. Instead, they just jam it in gear and grind the teeth down. This is a common thing that happens to many transmissions, both tractors and automobiles. To replace the reverse idler, the entire transaxle must be completely disassembled. There is no other way to fix it.

By the way - all IH gear drive transaxles use the same shifter forks from the "Original" until MTD made the 3 piece aluminum case. And you use caution if using an aluminum case transaxle for competitive pulling. Aluminum don't have the strength that the cast iron ones does. When pressure is applied to the case (the gears pushing against each other under stress; the case is what holds the gears together), the aluminum case will sometimes crack or break.

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Machine Shop Services - Complete Cub Cadet transaxle repairs, gear changes and modifications. Labor is $200.00 & up. Parts are extra charge. Install custom gears in your Cub Cadet transaxle - $200.00 labor. Drill 5 new holes (on 4-1/2" bolt circle) in the rear axle flanges that originally have a 4 bolt pattern for use of 5 hole garden tractor wheels - $60.00 labor, for two flanges. Tap threads in drilled holes above for reversed bolts to serve as studs - $20.00 labor, for two flanges. Fabricated hub/flange like the one pictured to the right: $100.00 per pair, plus shipping. NOTE: The hubs and flanges that I make will slide on with little or no modifications. All I need to know are the diameter of the axle, width of the keyway, length of the hub, bolt pattern and spacing of the bolt circle. I can also accurately fabricate wheel hubs, axle flanges, drill Chevy wheel bolt pattern in Ford axles and etc. By the way - these are not CNC machined. I fabricate these manually in my lathe and on my milling machine. Please contact me if you're interested in any of the above services.
If your IH Cub Cadet shift lever is loose, has a lot of play or just feels "sloppy," and if you can't repair it yourself or find someone else to repair it, I can fix it for $25.00 labor, plus return shipping.	Hydrostatic Transmission Oil Filter: Fits Cub Cadet models 123 through 982, and some newer models with the same style hydro. Replaces Cub Cadet IH-395789-R2, 723-3014 & 923-3014. Dimensions: 3 1/2" o.d. x 3 3/4" height, Thread Size: 3/4-16 NF. Micron: 16. Made in USA. $12.00 each, plus shipping. Part # 19-6680 or 120-265
Used IH Cub Cadet coarse spline axle shafts w/wheel flange. These are in excellent condition, not twisted, bent or damaged. $20.00 each, plus shipping. [When available.] Used IH Cub Cadet Coarse Spline Differential Carrier Assembly. These are in excellent condition. [When available.] - Light duty one-piece carrier. Good for general yard use. Not for competitive pulling. Without ring gear: $40.00 each, plus shipping. With ring gear: $60.00 each, plus shipping. Heavy duty one-piece carrier. Good for competitive pulling. Without ring gear: $60.00 each, plus shipping. With ring gear: $80.00 each, plus shipping. OEM ring gear alone. (excellent condition) $25.00 each, plus shipping.	Oil seals for 1" diameter rear axle shafts. Fits Cub Cadet (except Original model) and other makes & models of garden tractors and garden tiller gearboxes. 1" i.d x 1-1/2" o.d. x 1/4" thickness. $1.80 each, plus shipping. New bronze bushings for IH Cub Cadet rear axle housings. For axle shafts. 1" i.d. x 1.125" o.d. x 1" long. $4.00 each, plus shipping. New needle bearings for IH Cub Cadet rear axle housings. For axle shafts. Free up some friction! 1" i.d. x 1-1/4" o.d. x 1" long. $4.00 each, plus shipping. E-clip for Cub Cadet coarse or fine spline axles. 5/8" i.d. (coarse) or 3/4" i.d. (fine) .25¢ each, plus shipping. Please specify which clip you need. Grade 5 bolts for use as wheel studs. (Install from back of wheel flange to serve as studs for wheels.) 7/16" diameter, fine thread (7/16-20 NF) x 1-1/4" long . $3.00 per set of 10, plus shipping. NOTE: Chrome-plated acorn-style lug nuts are available at most auto parts stores and on eBay. Be sure to get the ones with 7/16-20 NF threads. These particular nuts fit the 1970 and earlier Chevrolet (GM) cars and 1/2 ton trucks.
Creeper drive unit rebuilds: $75.00 labor, plus return shipping. Installation of new parts are extra charge.
Used OEM IH Cub Cadet 12 tooth input pinion shaft/gear - $40.00 each, shipping included. [When available.] New high quality, high speed precision ball bearing for Cub Cadet input pinion shaft/gear. Part # 6203-2RS/C3 EMC - $7.00 each, shipping included.

How to Replace a Broken Shifter Fork in an IH Cub Cadet Transaxle -

1. Drain the oil from the transaxle.
2. Remove the transaxle from the tractor and place it on a sturdy work bench or table.
3. Remove the rear cover.
4. Remove the large gear that's in the front gear reduction housing and remove the gear reduction housing itself.
5. Remove the shifter lever/top cover assembly.
6. Remove the shifter fork retaining bolt.
7. Rotate the shifter rail with pliers to unseat the poppet ball.
8. Using a bendable 3/8" steel rod, drive the shifter rod out of the transaxle housing forward and out of the housing. Be sure to hold your finger over the hole for the poppet bore to prevent the ball from flying out when the rail are being removed!
9. The shifter fork can then be lifted out.
10. Installation is in the reverse order of removal. Except use a 1/4" roll pin punch to depress the poppet ball so the shifter rod can be inserted.

How to Change the Gears in an IH Cub Cadet Transaxle -

To replace 2^nd and 3^rd speed gears, the entire transaxle must be removed from the tractor and completely disassembled. But first, when you get the replacement gears, stack them on top of each other, arrange them in the order they go in the transmission, to see if the centers match up. Align them perfectly, too. If in fact they do match up, mark each one to avoid confusion during the installation process. After doing that, you can drain the oil from the transmission, and then remove the transmission from the tractor. (By the way - the transaxle, completely assembled, weighs 150 lb. So if you have trouble lifting it by yourself, ask someone to help.) With the housing on a sturdy work bench, support it with wood blocks. Now, remove the reduction drive unit, then remove the rear cover. The rear differential unit (carrier assembly) must be removed first in order to replace the gears.

The procedure to remove the carrier assembly is as follows:

1. Drain the oil from the transaxle.
2. Remove the rear cover
3. Use a large flat screwdriver and hammer or two large flat screwdrivers to remove the E-clip snap rings from the inner ends of the axles and then pull the axles out of the housings.
4. Remove the axle housings
5. Remove the bearing flanges.
6. The carrier assembly can now be removed from the transaxle housing.

Exploded View of the IH Cub Cadet Differential Assembly

Exploded View of the IH "Original" Cub Cadet Differential and Shifter Assembly

To remove the differential unit, first remove the 3-bolt flanges from the housing. NOTE - identify the number and thickness of shims removed from the each side for aid in reassembly. And it may be necessary remove the side bearings from the differential case for ease of removal. Then remove the differential carrier from the case. To remove the carrier, remove the flanges on each side of the case, then carefully remove the carrier.

Now, remove the shift lever/top cover assembly. Remove the shift fork retaining bolts. Rotate the shifter rails with pliers to unseat the poppet balls. Using a long drift (or rod) from the differential end, drive out the shifter rails forward and out of the housing. CAUTION! Hold your fingers over the holes or insert a 1/4" roll pin punch into the poppet bores to prevent the balls from flying out when the rails are being removed!

Remove the bolts from the main shaft bearing retainer and bump the main shaft and bearing forward and out of the housing. The upper 1^st and 2^nd/3^rd sliding gears can be removed as the shaft is removed from the housing. Inspect the reverse idler gear for excessive wear or damage and replace it if necessary. Otherwise, the reverse idler gear doesn't need to be removed.

Remove the countershaft nut and bump the shaft rearward out of the housing. The lower gears and spacers can now be removed. Note the sequence of the spacers and gears for correct reassembly!

Correct Installation of Cub Cadet Gears and Spacers on Countershaft (Bevel Pinion)

Inspect all parts for wear, clean the housing and install the parts in reverse order of above.

NOTE - When installing a set of special-made 2^nd and 3^rd speed gear set (especially a 21 tooth and higher second speed gear), the shift fork and sometimes the lower (inside) front portion of the transaxle housing may need grinding for gear clearance and for the bottom 3^rd gear clearance, because the aftermarket lower 3^rd gear is wider than the stock one. After tightening the nut on the pinion shaft, rotate the shaft/gears by hand to check for noise, adequate clearance and smooth rotation before permanently installing! Also, before installing the shifter cover, shift all the gears by hand and check for correct bottom and top gear tooth alignment. Being the center part between the 2^nd and 3^rd aftermarket upper gears are larger in diameter, you'll probably need to grind out the center "U" shape of the shifter fork. Or if you wish, instead of grinding the original shift forks for clearance, you can order special-made shift forks that will clear the 21 tooth and higher gears from True Gear and Spline.

The bottom 2^nd and 3^rd speed aftermarket pulling gears are wider than the OEM gears. Therefore, the tapered spacer needs to be narrowed about .060"±. But measure the thicknesses of the OEM gears and aftermarket gears, and then subtract the difference from the tapered spacer. None of the other spacers needs to be narrowed. Doing this will properly align the bottom gears with the top gears, and it'll prevent pushing the pinion gear too far back, which will throw off the backlash in the ring and pinion gears. (The correct backlash of the ring and pinion gears is .003" to .005".) For accuracy and trouble free service, remove the metal from the spacer by chucking it in a small metal lathe (with a self-centering 3-jaw chuck). But do not grind on the lower gear itself! And because the lower 3^rd gear is larger in diameter than the stock one, slight grinding of inside the transmission case may be needed.

After completion, rotate the gears by hand using the input shaft with the shift forks in the neutral position, the gears should turn freely and there should be no strange sounds. Shift all the gears into position and look at the gear teeth mesh. They should be perfectly aligned. If one or two isn't aligned, then a couple of spacers are in the wrong place. And if there is a noise, the only two things that could be causing it is the shift fork(s) wasn't ground enough to clear the gears or the lower inside portion of the transmission housing to clear the lower 3^rd speed gear wasn't ground away enough.

And if you were wondering, ALL Cub Cadet transaxles are offset to the right when standing behind the tractor. They did this so the driveshaft will clear the steering box and so the driveshaft will be inline with the engine crankshaft centerline on the single cylinder Kohler engines.

Installing Three (3) forward pulling gears (with a working reverse gear) - (The two paragraphs below was written by Dan Floyd of Springfield, Missouri. His email address is: jeep30dhf@yahoo.com.)

Installing 3 forward pulling gears is exactly the same as the 4 gear setup with the exception of the reverse idler. You simply cut the opposite end from the spacer end of the reverse idler gear back approximately 1/4" and turn down the spacer end diameter a bit (to clear the gears). The reason for that is you will be moving the gear back towards the case of the transmission a bit. It is really very simple, especially if using the forks and spacers from Midwest Super Cub.

If you want to use your factory shift forks, you will only have to modify one. To do so, cut the forks off of the rail assembly and weld on new ones. I used a large, flat heat-treated washer with a side cut out to make one of mine after doing the first. Just place the gears in position with the rails in what gear it should be aligned the new fork. Tack weld it in place, then you can weld it on the bench to finish it. It isn't any big trick, no remachining the rails, no fancy gear grinding and no headaches. I did use an aftermarket spacer kit for the first transaxle I did. I kept the dimensions and made my own for the other installments. Their spacers let you use the original detents on the rails. Plain aluminum round stock can be used.

Listed below are the dimensions for making the spacers on a 3- or 4-speed Cub Cadet transaxle. Spacers listed in order going from the pinion bevel gear (lower shaft) towards nut: (Reverse gear - third or first - fourth gear, depending on gear selection.)

1st = spacer .350" thickness 2nd = gear reverse or first (depending on 3 or 4 speed) 3rd = spacer 1.220" thickness 4th = gear first/second (depending on 3 or 4 speed) 5th = spacer .073" thickness

6th = gear second/third (depending on 3 or 4 speed) 7th = spacer 1.220" thickness 8th = gear third/fourth (depending on 3 or 4 speed) 9th = original cone shaped spacer 10th = bearing, retainer and nut.

Installing Four (4) Forward Pulling Gears (with no reverse gear) -

The two forward gears that replaces the original 1^st and reverse gears installs pretty much the same way a custom set of 2^nd and 3^rd gears are installed. Except they install and operate in reverse of 2^nd and 3^rd gears. To install a set of four (4) forward gears, you'll need a set of special-made 4-speed shift forks and a 4-speed gear spacer kit (see pictures above or to the right) from an aftermarket dealer. To install the gears, the transaxle must be completely disassembled. Then you'll need to remove the reverse idler gear, shaft and boss. Take a torch and carefully cut the boss off, then use a die grinder to grind it smooth. Also grind the casting flash (ragged edges). You also may have to grind the case for gear clearance depending on the ratios that you choose. After all the grinding is done and the case has been cleaned, repaint the bare metal and let dry before reassembly. (Paint prevents oil from seeping through the cast iron case.) Make sure that the oil holes that feed the bearings are clear. You could replace the shift detent springs with the stiffer YELLOW springs.

Cross Sectional View of IH Cub Cadet Transmission

Exploded View of Cub Cadet Transmission Gears and Components

If your tractor sometimes "skips a gear tooth" in the transaxle when pulling, this is caused by the flimsy OEM stamped steel front pinion bearing retainers. They'll flex when placed under a load. What happens is the lower stationary gears on the pinion gear/shaft are being pushed forward from the pressure of the ring gear, causing the bottom gears to become misaligned with the top gears, which allows them to skip a tooth. This could also cause the ring and pinion gears to skip, breaking the ring gear.

To prevent "gear skipping" and possibly breaking a tooth off a gear or ruining the ring and pinion gears, you'll need to install a set of billet steel pinion bearing retainers on the bearing where the lower pinion shaft protrudes through the front of the transaxle case. You can get a new set of billet steel pinion bearing retainers from Midwest Super Cub (http://www.midwestsupercub.net/).

The "original" (belt to disc clutch drive) Cub Cadet had the rear end differential carrier installed with the spider gears on the right of the ring gear (viewed with the operator sitting in the seat). The transmission gears turns in the same direction as the engine.

On the later model (direct disc clutch drive) Cub Cadets, which utilize a gear reduction housing, IH installed the carrier in reverse. The spider gears are on the left of the ring gear. This made the transmission gears turn in the opposite direction as the engine. The early and later carriers, ring and pinion gears are identical and are made to do this.

You must "flip the carrier" if you want to use an engine when the crankshaft PTO end turns counterclockwise when it faces the transaxle. Otherwise, it'll have 3 reverse gears and 1 forward gear.

So if you want to install an engine that turns in the opposite direction on a Cub Cadet, it's safe to flip a carrier to make your tractor go forward in the forward gears. And the ring and pinion gears will still mesh with no problem.

Click here to see a Cub Cadet "Original" with a 9-Speed Transmission!

To vary the speed of a belt-driven tractor, one can choose between different size engine and transmission pulleys (and/or belts). If you want a little faster speed in any particular gear, install a slightly larger pulley on the engine PTO or a slightly smaller pulley on the transmission input shaft. If one wants their tractor to run a little slower though, just do the opposite. This will change the ratio in reduction between the engine and transmission.

This section explains how to strengthen the stock Cub Cadet differential carriers and axles, and also it explains how to machine two different automotive differential carriers and axles for installation into a Cub Cadet transaxle.

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.

The stock Cub Cadet differential carrier (the part that the ring gear is fastened onto) is made from inferior or weak cast iron material. This means that they're not suitable for extreme pulling competition. Most unprotected stock carriers will break when used with a 13" hitch height, sharpened 26x12.00-12 tires and especially when hooked to a very heavy sled.

What happens is this: when a tractor is pulling, and when the weight of the sled comes up on the tractor, force on the spider gears (side gears and differential pinion gears, the four angled gears that's inside the carrier) places extreme outward pressure on the differential carrier, causing it to explode without warning. To reduce the chances of this happening, read below. Also, if you're running a lightweight pulling tractor (900 lb. w/driver) with a hitch height that's below the center line of the rear axle (10" hitch height), and small diameter rear tires (23x10.50-12), you don't have to worry about a stock carrier or axles breaking. The transfer weight of the tractor won't be placing that much strain on them.

What is the maximum horsepower recommended with a stock Cub Cadet carrier?

I don't think that question has just one answer. Because it's not necessarily horsepower that breaks a stock IH Cub Cadet coarse spline carrier and axles. The combination of engine size and torque, gearing of the tractor, weight of the tractor, tire size, if the tires have cut tread or not, hitch height, weight of the sled and track conditions all play a part in rather if a stock carrier and axles will break or not. To put it plain and simple, a heavy tractor with 26-12.00x12 cut tread tires and a 13" hitch height that pulls in 1st gear on a biting track is murder on a stock carrier and axles.

Use a "Heavy Duty" One Piece IH Differential Carrier for Competitive Pulling -

Most IH Cub Cadets that originally came with a single cylinder engine have a thin cast iron carrier. These carriers are weak and have been known to break under pulling strain, even when "strapped."

But the carriers out of the IH Cub Cadet models 582, 782 and 982 (red color tractors with a twin cylinder engine) are made of thicker cast iron material, which makes them stronger than the early "thin" IH carriers. In most cases, these carriers will hold up under pulling with a stock engine. The early "thicker" carriers used coarse spline axles. But the newer "thicker" carriers used fine spline axles. When installed in a stock pulling tractor, the fine spline axles shouldn't twist and break. And the two-piece MTD fine spline carriers are much stronger yet.

Weld the Spider Gears Together to Strengthen the Stock Cub Cadet Differential Carrier -

A sure way to prevent a stock carrier from breaking is to weld the spider (side and pinion) gears together. A welded or "locked" rear end will definitely provide superior pulling traction. But on the other hand, the tractor won't be as maneuverable as one with a free-spinning rear end. This means it would require a large area just to turn it around. Also, some extra weight (approximately 10 lb.) may be required on the front of the tractor to control it while going down the track. If one does decide to weld the spider gears, the carrier won't need a strap. Because under pulling stress, the spider gears wants to push outward, causing the differential carrier to break. But if the gears are welded, they can't push outward and break the carrier. Just weld the teeth together so they won't rotate on each other. And there's no need to remove the carrier out of the rear-end to weld the spider gears. You can reach in through the rear of the housing and weld side, then rotate the carrier and weld the other side. It's that simple. Use mild steel welding wire or rod to securely weld the spider gears together. Use some kind of metal shield to keep the welding splatter off the ring gear teeth. NOTE - welding of these gears is permanent! It cannot be undone!

A word of caution before welding the spider gears: if there's inadequate weight on the front of the tractor, a welded rear end could cause a high-speed pulling tractor to wander from side to side on the track. Therefore, that's why most pullers prefer an open (free spinning spider gears) rear end.

KEEP THIS IN MIND: If running you're a 13" hitch height and 26x12.00-12 tires, isn't a "100% guarantee" that stock [coarse spline] axles won't break. The above methods only lessens the chances of them breaking. If you have a high horsepower engine, it's best to install a re-machined automotive carrier and axles. Scroll down to find out what it takes to machine an automotive carrier and axles yourself. And as far I know, there's no posi-trac clutch packs for any carrier that can fit in the Cub Cadet transaxle. Therefore, the only way to make both axles pull at the same time in a Cub Cadet is weld the spider gears together.

Using Coarse Spline IH Cub Cadet Axles -

Anything with coarse splines will twist or break a lot easier than anything with fine splines. That's why the stock Cub Cadet axles twist or break easily, and that's also why late-model automobiles use only fine splines throughout the entire driveline, including the axles. Factory-hardened Cub Cadet coarse spline axles will ALWAYS twist at the splines whenever too much torque is applied to them. So when using coarse spline axles, try to use a set that's heat-treated to the center. To check for this, drill into the the center of the splined in. If the drill bit cannot bore into the axle, then the center is heat-treated. But if it bores into the axles, then the center is not heat-treated and the axle may break easily.

"Gun drilling" axles or making them hollow inline with the splines are is not a "100% guarantee" that they won't twist or break in pulling competition. But it will add approximately 15% more strength in the spline area. And stock axles should only be used in a pulling tractor with a stock engine, with an operating governor - maximum 4,000 rpm engine speed.

Install a Fine Spline Differential Carrier and Axles For Additional Strength -

Some of the later IH Cub Cadet models 682, 782, 1282 and maybe a few others have the fine spline side gears and 1" diameter axles, and the early-style cast iron carrier, which have thicker metal for increased strength. This carrier is about 75% stronger than the earlier coarse spline carriers. These carriers and axles can be used in a mild for pulling tractor. Only certain carriers and axles in the red color Cub Cadets are fine spline. You can't tell from the outside. The rear cover must be removed and an axle pulled to see if it has fine spline axles. As far as I know, the early model IH 582's and all of the model IH 1282's came with these particular carrier and axles.

The bolt-together fine spline carrier and 30 millimeter (1-3/16") fine spline axles were manufactured by MTD (Modern Tool & Die) and not International Harvester. This carrier and axles will fit in the early [coarse spline] IH Cub Cadet transaxles with no modifications, with the exception of swapping out the ring gear, carrier bearings and enlarging the axle housing ends for larger bearings and oil seals for the bigger 30 mm axles.

These units were used in the heavier [spread frame] garden tractors (mostly with a twin cylinder engine), and found in all Cub Cadets manufactured by MTD after serial number xxxxxxxx720000 (1983 and later). The serial number will probably have a long row of numbers, but if the last six numbers are higher than 720000, the tractor should have the fine spline carrier and axles. This includes all late model yellow and white gear- and hydrostatic-drive Cub Cadets with an aluminum transaxle case, except the model 582 Special, which have a Peerless 2300 series transaxle. (The 2300 series are very tough transaxles.) An easy way to identify the MTD fine spline axles is they have pressed-in automotive-style wheel studs w/lug nuts and not the screw-in lug bolts to fasten the wheels to the axle flange. The center of the flanges have that "automotive look" because the flanges are cast onto the axles and not welded. These may be quite as strong as the automotive carriers and axles. (See further down.) All Cub Cadet models that have the "heavy duty" fine spline carrier and axles are listed in the following link: Click here to identify which year of MTD Cub Cadet you may have.

The new style bolt-together MTD fine spline carrier is much stronger than the older cast iron one and the ends of the fine spline axles are larger and much stronger than the old coarse spline axles. There's no need to center drill through the axle splines either. In most cases, the ring gear may need to be swapped with an older IH angle-cut gear teeth ring gear because the ring gear teeth on the hydrostatic drive models of MTD Cub Cadet tractors are straight-cut. The old style IH ring gears will bolt directly to the fine spline carrier with no modifications, and the side bearing caps (flanges) will also interchange with the IH housing. They're a direct fit.

The splines on the IH and MTD fine spline axles are the same. The only difference is the IH axles are 1" in diameter the length of the axle, and the MTD axles are 30 mm at the wheel flange. This means when using MTD axles with IH axle housings, the ends of the housings will need to be bored to accept 30mm i.d. bushings or needle bearings in order for them to work.

The fine spline axles from an IH Cub Cadet are 1" in diameter. And the axles from all MTD Cub Cadets are much bigger, they're 30 millimeter (1.181" or close to 1-3/16") in diameter when measured at the wheel flange. When installing the fine spline axles (and carrier) in an IH Cub Cadet, larger bearings in the axle housings must be installed, too. One of the axle housings on the MTD's won't work on an IH Cub Cadet because the flange is too wide. Therefore, the IH axle housings will need to be bored and bronze bushings or steel needle-roller bearings (and oil seals) will need to be installed for the 30mm axles. The needle-roller bearings from the MTD housings can be reused and installed in the IH housings. But the oil seals should be purchased new.

NOTE: When installing the MTD fine spline, Chrysler or Pinto axles in an IH transaxle, and if the IH Cub Cadet has external axle [disc] brakes, the MTD or automotive axles won't work because the MTD brake discs are too big in diameter, and the automotive axles have no brake discs. Therefore, Midwest Super Cub offers aftermarket disc brake add-ons. Otherwise, an IH internal brake transaxle would need to be installed in the tractor.

Oil seals for the MTD Cub Cadet axles are PN-721-0187. The needle bearings are PN-741-0363. The axle housing gaskets are PN-721-3014. Rear cover gasket is PN-721-3015.

The splines on the 7-¼" Chrysler axles are much coarse (but still considered as "fine spline") and stronger than any fine spline Cub Cadet axle. Therefore, when used in a highly modified garden pulling tractor, sometimes the splines in the [Cub Cadet] side (axle) gears will strip out. The side gears from a 7-¼" Chrysler carrier can be installed in a bolt-together fine spline MTD Cub Cadet carrier. The side gears and axles from a 7-¼" Chrysler rear end will fit in a bolt-together fine spline carrier, and the Chrysler axles can be used, but the cavities in the carrier where the side gears rest will need to be machined (enlarged) to 1.501" so the side gears from the Chrysler will fit.

I believe that ALL fine spline axle/carrier tractors have external brakes. To install this type of carrier and axles in an internal brake transaxle, just knock out the wheel studs from the axles, remove the brake discs and reinstall the studs. You may need to swap out the ring gear, too.

Click here to learn how to install a John Deere carrier and axles in a Cub Cadet transaxle.

A Dana 30 carrier and axles out of John Deere models 140 above serial number 63,905, and all JD models 300, 312, 314, 316 and 317 will work in a Cub Cadet transaxle. Contact tuffy_puller@yahoo.com or 72buick@charter.net. They can tell you all about how to get a Dana 30 carrier and axles to fit in a Cub Cadet transaxle.

Information about Using a Chrysler, Dodge or Plymouth Differential Carrier and Axles in a Cub Cadet Transaxle - Top of page

The 7-¼" Chrysler carrier and axles are super strong. I think there's no way they will break in a highly modified garden pulling tractor.

This type of rear end was introduced in 1960. It has a 7-¼" ring gear. It has 9 bolts on the cover and a filler plug. It was a low performance differential unit that came in all cars with a slant 6 and some cars with a 318 cid engine. Casting numbers are # 2070051, 3507881 and 3723675. It came in any Chrysler, Dodge or Plymouth car from 1960 to the mid 70's such as the Aspen, Dart, Diplomat, Duster, LeBaron, Mirada, Valiant and Volaré. They were also used in the mid 80's in the down-sized Chrysler Cordoba, New Yorker, 5th Avenue and the Dodge Dakota trucks with a 4-cylinder engine. They're still manufactured today.

The newer (1978 +/- and newer) have changed the casting. Some are quite a bit wider and won't fit into the Cub Cadet housing. Some have the side gears offset from the centerline and the bearing cups are odd looking. If installed in a Cub Cadet transaxle, one axle will be longer than the other. One axle will need to be shorter than the other so they'll project out of the axle housings the same length. The late '60's Dart, Valiants and early '70's Demons works best. They're the ones with no ribs. The ones with the tall ribs, the knocked off ribs are the junkers.

The rear end that's needed for use in a Cub Cadet transaxle are ones with a 2.7:1 or lower ring and pinion gear ratio (2.76, 2.93, 3.23 and 3.55). Ones with a 2.22:1 or 2.4:1 ratio won't work because of ring gear flange offset location. The ratio can be found stamped into a small metal tag that's attached to one of the rear cover bolts. After founding the right rear end, the only the parts you'll need are the carrier with all spider gears intact and in good condition, the Timken roller bearings and races, and at least 15" of each axle (when measured from the spline end). The ring and pinion gears aren't needed.

How to Machine and Install the Chrysler Carrier and Axles in a Cub Cadet Transaxle -

The process to install a Chrysler-made automotive differential unit in a Cub Cadet transaxle housing is fairly simple. It can become time consuming fitting all the parts and getting everything shimmed and clearances set. And as always, for trouble-free service, take your time when machining any rear end for use in a Cub Cadet. Measure the parts/clearances with extreme accuracy before final installation.

Machine the Differential Carrier for Proper Fit: (Updated 12/23/08)

1. The only parts that's needed out of the Chrysler rear end assembly is the carrier, both axles (with the flanges), side bearings and races. Discard everything else.
2. Remove the Cub Cadet carrier and axles. Save the ring gear off the carrier because it'll need to be installed on the automotive carrier. The stock Cub ring gear is removed by drilling out the rivets. To remove the rivets, grind the end off each rivet, then use a 1/4" roll pin punch and medium size hammer to drive out the rivets, or drill the remaining rivets out with a 5/16" drill bit. Removing the ring gear from the automotive carrier is the same process.
3. The Cub ring gear can then be bolted to the automotive carrier by using either 5/16" fine thread grade 8 or stainless steel bolts with matching hardened nuts, lock washers and Loctite thread locker. There should be no problem of lining up the ring gear on the carrier, meaning the carrier shouldn't need to be machined. Just clean the parts, install the bolts and torque the nuts to 35 ft. lb. But if the inside diameter of the Cub Cadet ring gear is larger than the shoulder on the Chrysler carrier, when installing the gear, a precision machined spacer is required for the gear to be perfectly centered on the carrier. A machined spacer can be purchased from Zack Kerber at http://www.zkbrmachine.com.
4. Save the bearings from the automotive carrier and races from the rear end housing. The inside of the [3 bolt] Cub Cadet bearing retainers will need to be machined to accept the larger automotive bearing races. Also, the Chrysler carrier is .100" wider than the Cub Cadet one. So either bore .050" deeper into each retainer so the width of the carrier will have proper fit, or narrow the Chrysler carrier .050" on each side. This is performed in a metal lathe (with a self-centering 3-jaw chuck). Or just order a set of CNC machined steel bearing cups (retainers) from Lakota Racing or Midwest Super Cub, because the OEM cast iron bearing retainers may break if not reinforced with a steel cap. And by using the stock Cub Cadet shims, the carrier can be moved side to side to reach the desired lash between the ring and pinion gears. It's best to set the lash between .006" to .008".

Machine the Axles for Proper Fit:

1. Set the Cub axles aside. Nothing is to be used off of them.
2. On the automotive axles, measure from the splined end out approximately 14" and cut each axle off. Cut the wheel hub flange from each axle also. (The automotive flanges have the same bolt pattern as the Cub Cadet axle flanges.)
3. With the splined end of the axle in the chuck of a metal lathe (with a self-centering 3-jaw chuck), turn the entire diameter down to 1.000" and use the original bronze bushings or needle bearings in the Cub axle housings. Unless they're worn or damaged, there's no need to do anything to the OEM bushings or bearings in the housings. But do install new oil seals. The oil seal size is 1" i.d. x 1-1/2" o.d. x 3/8" thick. The oil seals are part # CR 9878 and National # 4712224. They're the same size seal that most garden tiller tine shafts use and the 5hp V50, 6hp V60 and 7hp V70 Tecumseh vertical shaft engines use on the PTO end of the crankshaft. But if you choose to machine the axles down to 1.125" (1-1/8") in diameter instead, then install either a 1.128" i.d. x 1" long bronze bushing or a Torrington roller bearing # B-1816 or equivalent (for a 1-1/8" shaft) and the oil seal is a National # CR11734 or equivalent (for a 1-1/8" shaft) in the axle housings. It doesn't matter which brand of bushings, bearings or oil seals are used, just as long as they're of high quality and the correct size. NOTE: The bronze bushings will need to be removed and axle housings will need to be bored to accept the over-sized needle bearings. To do this, you'll need to first measure the outside diameter of the needle bearing housing and then bore the axle housings .003" smaller for a press fit.
4. The Chrysler axles can have either an E-clip or a [1" or 1-1/8" i.d.] locking collar (like for the Pinto axles further down in this web page) to retain them in the carrier. If an E-clip is used, in the lathe, flip the axle end for end, and cut a .025" wide snap ring groove in the splined area .250" from the end.
5. Before welding the axles to the flanges, the axles will need to be pressed in the flanges. In the lathe, machine the ends of the axles (opposite the splines) .003" larger than the hole in the flanges, or bore a .003" smaller hole in the flanges. However it's done, just make sure it'll be a press-fit. The boring process for the flanges can also be performed in a indexing fixture or super spacer (with a self-centering 3-jaw chuck) that's fastened on the table of a vertical milling machine. Or fabricate two new flanges from scratch. For extreme accuracy, the five holes in the flanges (and wheel spacers) must be made in a super spacer or indexing fixture (with a self-centering 3-jaw chuck) that's fastened on the table of a vertical milling machine.
6. Using a hydraulic press, press the axles into the flanges.
7. In the lathe, true up the flange(s) with a dial indicator for zero run-out. Weld the flange(s) thoroughly on each side for strength. FYI - Use a wire feed welder with mild steel wire to weld the flanges to the axles.
8. Allow the axles to slowly air-cool. Cooling them too quickly could cause the weld area to crystallize and become brittle.
9. Clean and sand smooth the area where the bearing and oil seal will make contact on the axle to insure a smooth bearing surface and leak-proof seal.

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If you need heavy duty Cub Cadet transaxle parts such as custom gear sets, Chrysler carrier and axles, aluminum transaxle cases and etc., contact: Greg and Frank Edwards of Waynesboro, VA | Phone: 276-236-5305 | E-mail: sdrawde@ntelos.net | | Web site: http://gardentractorpullingtips.com/edwards/dart.htm Midwest Super Cub (http://www.midwestsupercub.net/) True Gear and Spline (http://www.true-gear.com) Vogel Manufacturing Co. (http://www.vogelmanufacturing.com/index1.html)

Information about Using a Ford Pinto, Mustang II or Mercury Bobcat Differential Carrier and Axles in a Cub Cadet Transaxle -

These rear ends are actually easier to install than the Chrysler unit because less machining is required. And they're just as strong. They'll hold up with no problems when used with a 50+ c.i. or a highly modified V-twin engine. The 1971-'80 Ford Pinto, Mercury Bobcat and Mustang II carrier and axles will work, as long as it's of the integral differential type rear axle, 6-3/4" ring rear design, 8 bolts on the cover and the car originally came with a 4 cylinder engine. And it's not the full size "Mustang," but rather the smaller "Mustang II." Also, some Mustang II's came out with an 8" ring gear rear end with a removable differential carrier and welded-on cover, which would be more difficult to install because both the carrier and axles are bigger. (Actually, an 8" Ford carrier and axles will work, but a lot of machining is required. Ask Chuck Vogel for details.) Click here for more information regarding the correct model of Pinto rear end to use. Read about Jim Williams' experience with a Pinto rear end.

Remember - Ford made two (2) different size axles for the Pinto rear ends. Some have a spline o.d. of .982" and some have an o.d. of ± 1.045". If you have the smaller axles, you need to only turn them down to 1.000" and use the original bearings or bushings in the Cub axle housings. There's no need to do anything to the OEM bronze bushing or needle bearing on the housings. Just leave them alone but do install new oil seals. But if you have the larger axles, they'll need to be machined down to 1.125" (like the Chrysler axles), and then in the end of each axle housing, use either a 1.128" i.d. x 1" long bronze bushing or a Torrington bearing # B-1816 or equivalent (for a 1.125" diameter shaft) and the oil seal for the axle housing is a National # CR11734 or equivalent (for a 1.125" diameter shaft). It doesn't matter which brand of bushings, bearings or oil seals are used, just as long as they're the right size.

NOTE: If you don't want to use the original bronze bushings, and if you wish to install needle bearings for less friction, you will need to remove the bronze bushings and the axle housings will need to be bored to accept the needle bearings. To do this, you'll need to measure the outside diameter of the needle bearing housing and then bore the axle housings .003" smaller for a press fit. Or, look for another set of axle housings off a later model Cub Cadet with the [1" i.d.] needle bearings already installed.

How to Machine and Install a Pinto Differential Carrier and Axles in a Cub Cadet Transaxle -

As always, for trouble-free service, take your time when machining any rear end for use in a Cub Cadet. Measure the parts/clearances with extreme accuracy before final installation.

Machine the Carrier for Proper Fit:

1. The only parts that's needed out of the Pinto rear end assembly is the carrier and both axles. Discard everything else.
2. The Cub Cadet ring gear fastens on the opposite side of the flange where the Pinto ring gear originally went. Don't use the original Pinto ring gear bolt holes in the flange to fasten the Cub Cadet ring gear to. They're too big and they don't line up properly. Also, the ring gear could slip and/or break when under severe pressure if the Pinto's ring gear holes are used. Instead, align the ring gear on the flange so the holes are halfway between the Pinto bolt holes, and clamp the ring gear on the flange. Now drill new 5/16" holes into the flange (it's just soft metal) through the ring gear holes for perfect alignment. Use 5/16" diameter grade 8 or stainless steel fine thread bolts with a 3/4" shoulder, split lock washers and grade 8 nuts to secure the ring gear to the flange. Torque the bolts to 35 ft. lb. This may seem kind of tight for 5/16" bolts, but they must be this tight to prevent the ring gear from slipping and possibly breaking.
3. The Pinto carrier's ring gear flange is too large for the inside of the Cub Cadet ring gear to fit so the outer edge will have to be turned down to exactly 5.705" for a correct fit of the Cub Cadet ring gear. Don't machine it any smaller, or the ring gear will be too loose and not turn true on the carrier.
4. The original Cub Cadet side bearings will fit perfectly on the Pinto carrier with no machining.
5. The overall width of the Pinto carrier must be narrowed to 3-15/16" (3.9375") in order to fit inside the Cub Cadet housing. Machine only the long end of the Pinto carrier. Use the Cub Cadet carrier as you will need it to take some measurements for the Pinto carrier.
6. Install the Pinto carrier (with the Cub Cadet ring gear) in the Cub Cadet housing. You might need to use more or less shims depending on the amount of machining.

Machine the Axles for Proper Fit:

1. From the splined end to about the middle of the axle, cut off each Pinto axle to 12-1/2" long. Discard the rest of the axle/hub. You can make them longer if you want your tires to set out farther. NOTE: The splined part of the Pinto axles are small in diameter. The rest of the axle is larger in diameter.
2. In the lathe, machine the larger diameter portion of each Pinto axle down to 1" in diameter. Be sure to clean and sand smooth (polish) the area where the bearing and seal will ride on the axle to insure a smooth bearing surface and good seal. The oil seals are part # CR 9878 and National # 4712224. They're the same seal that most garden tiller tine shafts use and the 5hp through 7hp Tecumseh vertical shaft engines use on the PTO end. The size is 1-1/2" o.d. x 1" i.d. x 3/8" thick. NOTE: The splines on the end of the axles are either .982" (23 spline axle) or 1.045" (25 spline axle). The axle then steps up to over 1.125" the rest of the axle length. Basically, you will not turn the spline but only the area between the spline and the wheel mounting flange.
3. Fabricate two new wheel flanges, or in the lathe (with a self-centering 3-jaw chuck), machine the weld from the Cub Cadet axles next to the wheel flange and then press the flanges onto the Pinto axles. True up each hub (in the lathe with a 3-jaw chuck), then weld them onto the axles. For strength and durability, weld each side of the hub. Discard the Cub Cadet axles, or keep them for future use in a stock tractor. FYI - I've always used mild steel wire welder to weld the wheel flanges to the axles. I weld them on both sides of each flange and never had one break loose.
4. Now, you need a couple of steel "locking shaft collars" to retain the axles in the rear end. These collars measure 1" i.d. x 1-5/8" o.d. x 5/8" in thickness and they have an Allen set screw.
5. Drill a small hole in each axle housing exactly 1-1/2" from the end. These holes will allow access to the set screw in the collars. Cut threads in the holes for either a short bolt or a NPT threaded pipe plug. Leave the original Cub Cadet bronze bushings or needle bearings and oil seals intact, or install new seals to prevent oil leakage.
6. Fasten the axle housings onto the transaxle case with a couple of bolts and then slide the Pinto axles in until they bottom out against the pinion shaft.
7. Place a punch mark on each axle through the drilled holes. This is to locate the set screw in the locking collars.
8. Remove the axles, and then drill a shallow hole into each axle where the punch mark were made. This shallow hole is for the set screw in the collars to tighten into, and to keep the collars from slipping on the axles.
9. Remove the housings from the transaxle case then slide the Pinto axles in along with the locking collar on each axle.
10. Fasten the housings onto the transaxle case, locate the set screw in each collar through the drilled holes and then tighten them securely into the shallow hole that was drilled in the axles.
11. After tightening the set screws on the axles, plug the holes in the housings with either a short bolt or a NPT threaded pipe plug. There's no need to install a grease fitting in the holes because the oil in the transaxle will provide adequate lubrication for the bushings or bearings.
12. See the detailed drawing below for how the axles are held in place.

NOTE: I haven't machined any carriers or axles yet. Most of the information in this web site came from other machinists who have machined them and was kind enough to share the information. - Brian Miller

Remember, when installing an automotive rear end in a Cub Cadet, it's important to install a steel (3-bolt) flange on the side of the transaxle that's closest to the ring gear (the right side, as viewed when sitting on the tractor). The reason for this is because under pulling stress, the pinion gear pushes against the ring gear. And the only thing keeping them together is the original 3-bolt cast iron flange, which could break. Or better yet, install 2 steel machined flanges, one for each side, like the ones pictured on the right. Midwest Super Cub sells machined flanges for the Chrysler carrier. When using a Pinto carrier, install an 1/8" thickness steel plate over the original flange that's closest to the ring gear. See the picture of them to the right.è

What type of oil should be used in a Cub Cadet transaxle?

For the IH and MTD Cub Cadet transaxles, the official Cub Cadet repair manual says the recommended oil to use is Hy-Tran B-6, Hy-Tran PLUS (MS-1207), Hy-Tran ULTRA or equivalent. "Equivalent" means that it's safe to use any quality, name-brand hydraulic oil that meets or exceeds CASE/IH requirements. These oils can be used in both the hydrostatic and gear drive transaxles. Most Farm and Home stores should have Hy-Tran in stock. When or if you do find Hy-Tran, look on the back label of the IH/Case hydraulic oil containers. It should say something about Hy-Tran. And always use hydraulic oil in a hydraulic system. Fill it where there's a fill and oil level check plug, not any place else.

If Hy-Tran isn't available locally, then it's safe to use virtually any type of hydraulic oil, power steering fluid, hydraulic jack oil (which are nothing but ordinary hydraulic oil), Dexron^® III Mercon^® automotive automatic transmission fluid (ATF) or Hy-Tran in a Cub Cadet or other makes and models of the gear drive, hydrostatic drive transaxles or hydraulic systems. Dexron^® III Mercon^® is a very durable and high quality hydraulic oil with a red dye and scent added to determine it from other oils when it leaks from equipment. It also has a rust inhibitor and it helps keep the inside of a transaxle clean. It's available at most auto parts stores and in the automotive isle at most major department stores.

Hydraulic oil, automatic transmission fluid or Hy-Tran should be used in the gear drive transaxles. These oils will provide adequate lubrication for all moving parts, with no problems. And there's no need to worry about the gears, bearings and other internal parts wearing prematurely because of the low viscosity (light-weight or thin) oil. The parts are made of extremely hardened material. Synthetic oils will allow the internal moving parts to operate much cooler. And being gear drive transaxles don't have a hydraulic pump like the hydrostatic units do, the oil will never get hot. The above mentioned oils protect automatic transmission parts, don't they? And auto transmissions work a lot harder and operate for longer periods of time than any garden tractor transaxle ever will. Personally, I've always used Dexron® III Mercon in my gear drive transaxles since I've started pulling, and I've never had any problems.

Correction: Never use motor oils in a garden tractor transmission or transaxle. Motor oils doesn't have rust inhibitors and the internal parts in the transaxle will rust just above the oil line when stored in a cool, damp environment. The parts will rust so bad, they will look like they've been sitting out in the rain.

For pulling competition, don't use high viscosity (such as SAE 90 weight) gear oil when filling the Cub Cadet, Peerless, Wheel Horse or any other gear drive transaxle. This also applies to automotive manual transmissions and rear ends used in mini-rod pulling vehicles. Use the oils that's mentioned in the above paragraph. Because gear oil is thick and heavy and when used with pulling competition, it will slow down the gears slightly and rob the engine of valuable horsepower. And if the transaxle has an internal brake (Cub Cadet), the tractor won't stop as well. And again, there's no need to worry about the gears, bearings and other internal parts wearing prematurely because of the low viscosity (light-weight or thin) oil. The parts are made of extremely hardened material. By the way - the only place that sells gears for a Peerless transaxle is a Tecumseh Engine dealer. And there are no special pulling gears made for any Peerless transaxle. The only alternative is to change the diameter of the pulleys (and length of belt) on the engine and transaxle to increase or decrease the ground speed of the tractor.

It takes 3-1/2 quarts of oil to fill a Cub Cadet gear drive transaxle. To fill a Cub Cadet transaxle, there's an 1/2" NPT tapered-thread plug on the rear cover of the transaxle. Use the extension of a 3/8" drive ratchet to remove the plug. Fill until the oil starts to run out of the hole. And then reinstall the plug. For pulling competition, less oil can be used in the transaxle. To do this, don't fill the transaxle full of oil (to the full level hole). Instead, tap another fill hole 2" (on the rear cover) below the original one and fill it to there. The lower driven gears and ring gear will still pick up plenty of oil and sling it on the upper moving gears and bearings, keeping them well lubricated. A grease fitting may need to be tapped into each axle housing end to help keep the axles lubricated as well.

What makes most hydrostatic drive and driven parts (gears) to wear prematurely isn't because the wrong type of oil was used, it's extreme heat. Whenever petroleum oil gets hot, it loses it's "thickness" or viscosity and turns thin. The hotter it gets, the thinner it gets. This is called viscosity thermal breakdown. Oil is supposed to keep all moving parts separated. But when oil gets hot, it gets thin, and this will cause the moving parts (gears and such) to make contact with each other (metal to metal contact) causing them to wear excessively. Extremely hot oil will cause the rubber seals to harden and crack, too. No petroleum oil, even Hy-Tran, is immune from thermal viscosity breakdown. Only full synthetic oil is 100% immune from thermal viscosity breakdown. So remember, it's very important to change the oil, keep the cooling fins that's on the hydrostatic pump/motor clean, make sure the fan that blows air over the hydrostatic pump/motor is in good condition, and do routine maintenance at least once a year before using the tractor, and the hydrostatic unit will probably last forever. By the way - a typical Cub Cadet hydrostatic drive transaxle takes 7 quarts of oil to fill it full.

A non-synthetic oil will provide superior lubrication as long as you keep the cooling fins and hydrostatic drive areas clean and free of grass and debris. Make sure the fan on the driveshaft is in good condition, too. Clean the fins and hydrostatic drive areas the beginning of every year and the hydrostatic drive system should last a lifetime. Return to top of page. È

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If you need a narrowed automotive rear end, 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: E-mail: pullingtractor@aol.com. We are in the process of relocating our shop/business to a much larger facility at 1712 Business Loop 70 East, in Columbia, MO, offering faster service and many more parts & services to our customers! 1712 Business Loop 70 East, Columbia, MO - Google Maps or Map of 1712 Business Loop 70 East, Columbia, MO by MapQuest. These rear ends can be used for the weight box in a sled, in a mini-rod or under a street rod! When ordering, please specify make, overall width, gear ratio and wheel bolt pattern. Details include: 8", 9" Ford or a small GM, Ford or Import automotive rear end with factory 4:1± ring and pinion gear ratio, or whatever custom gear ratio you desire. For a sled, narrow housing as much as possible (26" - 29" overall width, axle flange to axle flange) or to whatever width you desire. For a sled, install a 12 tooth sprocket for a #50 chain on the right axle flange (when facing the center yoke). For a sled, install the brake drum and brakes with a long parking brake cable on the left axle when facing the center yoke. Have Moser Engineering professionally shorten and respline the axles. Price: $700.00, sled rear end with factory ring and pinion gears, or $1,200.00 for street rod or mini-rod with brakes on each axle, and custom ring and pinion gears, plus shipping.

Linked pages to my parts & services:

Please click HERE, e-mail me at pullingtractor@aol.com or call me at 1-573-875-4033 if you need machine work performed, repairs made, various parts, if your business would like to help sponsor my web sites or if you'd like to make a donation towards my web sites. Please call between 12 noon and 8:00 p.m. Central time, and please be patient because I stutter.

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