Last weekend we removed the clutch and flywheel from a low milage, 1991 ZR1 to correct a noise problem from the throwout bearing and/or the pilot bearing.
Upon removal of the clutch, I noticed an interesting wear pattern on the flywheel, the clutch and the clutch disc:
Here is the clutch pressure plate face:
Here is the flywheel surface:
Here is the clutch disc:
Notice that the inner third of the friction surrface shows a different pattern that the rest of the surface. There seems to be significant material transfer to the pressure plate and flywheel:
Clutch:
Flywheel:
The dual-mass flywheel internal dampers have failed and the relative motion of the parts is about 25 degrees with a "hard" stop at each end of travel.
The only other unusual thing we found was that the pilot bearing inside diameter is off center:
We replaced the flywheel, clutch, disc, throwout bearing, and the pilot bearing.
Any thoughts of the cause of the wear patterns?
Jim