154 Clutch issues

[spareparts]

I'm servicing a 154 drive line. The shaft was running out quite a bit at the clutch end which led to the teardown. At this point it's all apart. The pilot bushing is egged out in the clutch flywheel. The clutch flywheel is a somewhat loose fit on the transmission input shaft and probably would not run true/square. It's quite clear the clutch was taking up on one side more than the other due to uneven wear on the pressure pate and flywheel. My background is mechanical design and machining. This tractor belongs to a club and the clutch was serviced with new parts less than 10 years ago. The previous person to service it said he didn't think the clutch flywheel was wobbly on the input shaft when he assembled it.

I was unable to locate specs/tolerances for things like the input shaft, driveshaft pilot diameter, and bushing in the throwout bearing. Anyone have these numbers? The parts don't look terrible, but the flywheel to input shaft connection is not what I would expect in terms of clearance.

It seems like an incorrectly adjusted clutch brake could put excess pressure on the clutch flywheel and wear the shaft/flyweel connection. The buttons were completely worn and when I got to taking it apart and it didn't appear to be adjusted correctly.

How much work is it to replace the transmission input shaft, if this also needs to be replaced?

[RaymondDurban]

…. The buttons were completely worn and when I got to taking it apart and it didn't appear to be adjusted correctly.

How much work is it to replace the transmission input shaft, if this also needs to be replaced?

This is the most common problem with the number series Loboys, improper setup and maintenance issues to keep everything working within specs. Leads to damage and cobbled repairs.

If you have things apart to the point that you have the transmission flywheel off, pulling the transmission shift cover and removing the input shaft is not much more work. Just keep a free hand on the gears and remove one at a time as the shaft slides forward and out.

[spareparts]

The plan was to buy a new clutch flywheel and see how things fit. Order more parts as necessary. Trying to keep costs low, this approach isn't the best. Without specs it's hard to figure out what is worn.

[spareparts]

The job is done. Because I could, I faced the flywheel and sleeved it to fit the transmission input shaft. Bought a new pressure plate and throwout bearing.

The failure was caused by a broken clutch lever. One of ears on the lever that hooks under the pressure plate pin broke. So it probably wasn't fully disengaging. This in turn wore the clutch brake out real quick and put side load on the pilot bushing.

The pilot on the drive shaft should be .620" or so. The same spec as the Farmall Cub.
Bob of HamiltonBobs gave me a dimension for the transmission input shaft but I lost it now. It was OK too.
I didn't measure the shaft where the throwout bushing sits. The old throwout bushing was definitely worn after rattling around on the shaft for some time.

[CharlieK]

thanks for that update

[Duner]

Thanks for update. I have shimmed my flywheel , maybe I need a sleeve. I was thinking some sort of taper lock scheme. Just dreaming.

[spareparts]

Taper lock would be a good solution. I'm actually quite surprised someone hasn't designed aftermarket improved parts for these over the years.

I used 3.5" socket head cap screws cut just long enough for the nut to fit for the driveshaft pins. The engine side of the shaft was OK, but the transmission input shaft was very worn with threads clearly worn into the side of the hole. You want 1.25" of unthreaded section. 3.5" bolts are about 1.5" unthreaded(the spec actually calls for a minimum threaded section so it can vary) which is fine in the front, but on the input shaft I added two washers under the head and nut to be able to tighten it. This just barely clears the clutch brake bracket. I was too lazy to add another 1/4" of thread.

Next issue will be the oil filter. I've been told it hasn't been changed in years because it's near impossible to get the cover to seal. I may make a cover which uses o-rings instead of the existing gaskets.

[Gary Dotson]

I made oil filter covers for my Cubs, from aluminum bar stock, with captive o-rings glued in place. They also seal to the bolt with o-rings. They work great, never a leak and the bolt only needs to be tightened lightly.