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You may get more responses if you put this in the Pulling or the Garden tractor forum. Yahoo has a good Sears tractor group also. If you want the sport of Pulling, then go ahead and have fun. I will point out a couple of things about the Sears that make them a better puller though they may never be as tough a puller as a tractor with real cast iron rear ends. One thing that is weak is the differential. The transaxle is tough as nails but the differential breaks in two ways. First is the side plates (especially the inside one) on the pinion gears needs to be remade from real steel. In fairness, these usually break because the end of the axle explodes which brings me to the second weakness. The axles. These seem to be made by compressing iron powder in a mold, like some oil pump gears are made amoung many other small metal parts. This process works OK for what they were really designed for but not so good for overloading. If these were machined they would cost more than the tractors I suppose. What I have found works is to have the axles made, or make them yourself if you have access to a mill cutter. Use a good cold rolled steel shaft and they will out perform the originals. What the original axles do when their design is exceeded is this. The ends of the axle with the differential gears on them explode which is what tears up everything else inside the case.. Sometimes this damage will even blow out the bottom of the case. The "weaker" but more resilent cold rolled axles may twist or spin off the ends(I haven't seen this happen) but they don't explode and cause huge amounts of damage. These use an 11 count spline which is kinda strange as it makes for an odd degree count when machining. The cute thing about machining them is that even a machine job that needs a little filing or grinding with a speed cutter(I hate to throw away a couple hours work) to fit the gear or wheel hub on will still outperform the originals. You can change the input pulley to play with gear ratios as the GTV series used a smaller input pulley than the Hi-Lo range tranny did. The next thing about the sears set-up is to put as much weight as possible on the wheels and in the tires. The final thing I will say about making these stay together while pulling is to have the wheel hubs machined so you can put pillow block bearings directly on them so the axles do not have to handle the strain of the torque AND pulling loads. At the very least if you don't put pillow blocks on then support the very ends of the transaxle housing where the axle comes out so it won't flex there before it puts the load stresses to the frame. Have fun. Old sears tractors are numerous for parts. You can put a lot of power through these transaxles stock so just enjoy and learn. And,,use synthetic gear oil.
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