# B7100 HST premature clutch failure



## marky1 (Apr 28, 2014)

I had posted a while back aboout springs coming off the clutch disk causing much noise in bellhousing. I had dug them out of the bell housing and it kept working, but recently one became wedged . Had to split the tractor. Clutch was replaced only 20+ hours ago by previous owner. On this HST tractor, it's only function is to engage the PTO. like enguging belly mower, which is all tractor is used for. So clutch was actually used very little. 

-clutch facing looks like new (except spings came out of it). 
-flywheel was obviously machined, and shows no sign of wear or heat problem where asbestos disc contacts (Can still can see all swirl machine marks and no marks whatsoever related to disc engagement). 
-Pressure plate looked new excpet banged up from broken springs off clutch disc. 
-T/O bearing is like new. 
-Pilot bushing was shot and I appears to have not been replaced by previous owner???? 

First clue to this problem started by hearing growling/ howl when clutch pedal was depressed (dis-engaged) that seemed to subside at low RPM. 

Trying to figure out what made springs come out ????

Clutch did not slip or make noise when engaged. 

My theories

- Would a growling roar noise from clutch (when pedal depressed) be caused by slop/binding at pilot bushing and cause disc springs to break or come out? I'm thinking the pilot bushing was the problem all along.

-Could have been a defective /cheap rebuilt/out of balance disc

-This tractor has a removable backing plate that bellhousing bolts to at rear of engine that appears to have been bent. Maybe imput shaft was not aligned all along or it may have bent when spring became lodged in bell housing and shut tractor down suddenly? I am going to replace this bellhousing attachment plate also. 

-Could it be that flywheel was not machined flat? I plan to resurface just in case 

I will check the tranmission imput shaft and engine crankshaft when I get new pilot bushing to make sure no wear at these points. Imput shaft does not look bad and previous owner said he had replaced the shaft. 

I'm going to start over with all new parts in hope of solving problem. 

Anything else I should be looking at for premature failure? 

Any thoughts are appreciated!

mark


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## marky1 (Apr 28, 2014)

*problem found*

Guy who did the clutch previously did not deal with pilot bushing, discovered after splitting tractor, that was what caused clutch to shake apart I think. Crankshaft end had some wear due to using so long with worn out bushing. Had to find a bronze bushing and machine it to fit crankshaft end. Working good now.


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