125 Drive shaft
 

Since my engine is at the machine shop I took the opportunity to change my driveshaft because it isn’t very straight and was causing vibration. So I consulted my shop manual on how to split the tractor because I thought it would be easier. The directions and illustrations are good, but the tractor in the manual doesn’t have a sleeve hitch. When I had the seat and fenders off, the seat support is connected to the lifting mechanism. By the time I got there, I could see the back of the hystat pump but not the drive shaft connection. I decided to put it all back together and try a different route. Has anyone here changed a driveshaft on a 125 while the engine was out? What am I doing wrong, or how can I change my approach?

Did you try unbolting the Drive Shaft Adapter (#1) from the Flex Disc (#50) and simply pull out the Drive Shaft ??

:bigthink:

No, but I will this weekend. Thank you.

The #2 part almost always by this time of age, will have significant wear resulting from the hardened coil pin in part#1. Other causes of vibration are any or all driveline assembly components. From the shaft, shaft coil pin holes, shift couplings, and even the pump input Shaft. These models I respect the most of any when you consider the components needed to be removed for drive line refurbishment, it's really cool how well made these tractors are. The sponsors have all parts needed to correct. Just tear down and inspect . I have the perfect 1/4" punch that makes coil pin removal simple in the tunnel frame tractors such as thie 125. Easy Peazie lemon Squeezie!

I’d like to clean all the grime off the transaxle too, I went back out to the barn and had another look. I’ve just been so focused on the details of engine removal and tear down lately. It has a small hystat leak somewhere, but it’s impossible to tell right now because it’s so dirty. The differential cover seeps I’m sure of. Will that chemical called GUNK engine cleaner harm any external transaxle parts like seals? I really need to clean it before troubleshooting a leak.

Don't know how you are set up for moving things around and cleaning etc
but here is my plan of attack normally. Start dousing everything with
Simple green. As often as you think of it. Maybe do this for several days.
Knock the heavy stuff of as you go. Then it is off to the pressure washer.
I do this even before I split the tractor. Then when it is split you can
do it again. Lots of patience will clean it up nice. 50 years of accumulated
crud takes some doing to clean up. And worth every minute of effort.

Ken

I have an idea for splitting:

Support the tractor with an A-frame (the rafters in my barn)
Take the rear tires off
Disconnect brake arm
Disconnect hystat control arm
Place floor jack under transaxle
Remove the bolts holding transaxle to frame
Roll transaxle out from under tractor
Clean it and put it back

Does this make sense? Can I do it a better way? Help from anyone who has split a 125 is appreciated.

Knock the heavy chunks off with air pressure.
Just stay away from seal locations, there aren't that many.
Are you planning a total cleanup and rehab or a full restoration?

The only reason for clean up is to find the leak under it. The diff cover seeps, but that’s an easy fix. Although I would love a genuinely restored Cub, I use mine for work around our mini farm and I would hate to mess up gorgeous restored yellow iron. All I’m after is a mechanically sound machine. There’s nothing wrong with the hystat system other than it leaks a little bit and it seems like the swashplate doesn’t have enough reverse throw. I feel this way because it goes twice as fast in forward as it does reverse.

That is NORMAL.

A common area of Hydro Fluid leakage, is the cork gasket between the Hydro Unit and the rear end.

Ok good info. I would definitely have to split it to make that repair. Do you think my splitting procedure I wrote earlier would even work?

Your plan will work fine. If you have jack stands you can place them
under the frame assuming front tires are still on. Then leave the rear
tires on also and just roll it out of the tractor frame.

Ken

To clean up gunk from parts I've had the best results with Dawn dish soap. I make everything wet and then take a scrub brush dipped in dawn dish soap and scrub and spray.

Got the drive shaft swapped with a nice one I found online. Good flex disc joint and good metal fan. I lifted the tractor up, removed the oil filter, removed the fan shroud, drove the pin out, pulled the old bent drive shaft and installed the new one. I had to use new screws to hold the fan shroud on. Not a bad repair.

I agree with what Ken said,the rear assembly is a hefty piece of iron to be lifting.By leaving the wheels on,you basically turn it into a balancing act.A block of wood under the front,missing that fragile tube and your good.Ken's method your working smarter,safer,not harder.