B21 Clutch Problem?

[100 td]

A couple of things to consider.
I personally would replace the rear main engine oil seal while you have it apart and any welsh plugs on the rear of the engine if it has any?
One other thing I would do if I had it in that state, drain tranny and axle housings, remove HST tank bottom cover and clean out sludge.

 

[brain55]

Can't quite see but looks like pilot bearing is toast? I'm wondering if it's the chicken or the egg, does the clutch spline slowly wear and then start to run out of centre and flog the pilot bearing, or does the pilot fail allowing the opposite to happen.
Given that this is a HST machine and the clutch is used rarely, meaning it's generally always engaged, I'd take a guess at the centre splines start to wear, and then each time the clutch is engaged it clamps a tiny bit out of centre causing out of balance and more wear and ultimate failure. I wonder if I can get a borescope in through the inspection hole and into the centre of mine for a look?
Looks like the throwout bearing carrier has touched the pressure plate fingers, should be able to take the burrs off the end and reuse.

The pilot bearing actually looks good to me. It's still intact and the yellow teflon like material looks good. I have seen B-series where the bushing was gone and the crankshaft was worn to where it had to be machined for a sleeve for the bushing to fit into. Your splines failed from shock loading not from shaft misalignment in my opinion.

 

[100 td]

Can't quite see but looks like pilot bearing is toast?

The pilot bearing actually looks good to me. It's still intact and the yellow teflon like material looks good.

OK, thought is was a bearing, not a bush, as I said, can't quite see.
What's the teflon in front of the bush for, or is it the bush lining?

 

[TomSeller]

The pilot bearing actually looks good to me. It's still intact and the yellow teflon like material looks good. I have seen B-series where the bushing was gone and the crankshaft was worn to where it had to be machined for a sleeve for the bushing to fit into. Your splines failed from shock loading not from shaft misalignment in my opinion.

You sure were right on the mark when you predicted the splines were gone. By shock loading do you mean quick forward/reverse movements as when repetitive FEL loading?

 

[RobbieBones]

OK, thought is was a bearing, not a bush, as I said, can't quite see.
What's the teflon in front of the bush for, or is it the bush lining?

At first I thought the pilot bushing looked bad but as you say the Teflon is on it. If I needed one where do you buy one? I haven稚 seen any on all the clutch diagrams I looked at.

 

[RobbieBones]

The pilot bearing actually looks good to me. It's still intact and the yellow teflon like material looks good. I have seen B-series where the bushing was gone and the crankshaft was worn to where it had to be machined for a sleeve for the bushing to fit into. Your splines failed from shock loading not from shaft misalignment in my opinion.

OK, thought is was a bearing, not a bush, as I said, can't quite see.
What's the teflon in front of the bush for, or is it the bush lining?

At first I thought the pilot bushing looked bad but as you say the Teflon is on it. If I needed one where do you buy one? I haven’t seen any on all the clutch diagrams I looked at.

 

[RobbieBones]

Standard clutch 'job' parts (Clutch plate, Pressure plate, Release bearing, Pilot bearing) and the splines on the trans input shaft look pretty beaten up - so you better think about replacing/repairing that. Maybe look at the input shaft bearing as well...
How's the flywheel facing?

Well done getting this far.

Flywheel looks great. The throw out bearing does have slight play when you rock it side to side but the trans shaft does not move.

 

[brain55]

At first I thought the pilot bushing looked bad but as you say the Teflon is on it. If I needed one where do you buy one? I haven’t seen any on all the clutch diagrams I looked at.

It's on the page with the crankshaft. The bushing and the seal both.

Most of the shock loading happens getting on and off the pedal quickly.

 

[RobbieBones]

The pilot bearing actually looks good to me. It's still intact and the yellow teflon like material looks good. I have seen B-series where the bushing was gone and the crankshaft was worn to where it had to be machined for a sleeve for the bushing to fit into. Your splines failed from shock loading not from shaft misalignment in my opinion.

Could the splines fail because the clutch pedal wasn’t adjusted right or needed adjustment periodically? The throw out bearing isn’t pressed into the fingers far enough to fully disengage?.????

 

[brain55]

Could the splines fail because the clutch pedal wasn’t adjusted right or needed adjustment periodically? The throw out bearing isn’t pressed into the fingers far enough to fully disengage?.????

Not likely. The clutch if partially disengaged would slip, absorbing the load that way.