Given vehicles that are old enought that they would likely have this problem, what are the most common causes of clutch chatter? I know the short answer is going to be that the clutch is worn out. But if it's got any meat left on the disk, why would it matter?
Like washboard on dirt roads, clutch chatter always seems to me like something that would diminish with age, but obviously this is not the case.
All I can imagine is that some portion of the flywheel face, clutch disk surfaces, or pressure plate surface, has worn differently that the rest of the surface, but I can't think of why that would be.
Any thoughts appreciated.