So I replaced my clutch disc, flywheel, pressure plate, and slave cylinder early this year. At first it was all good it ran and drove fantastic. After a few months it started to chatter really bad after about 30 mins of driving. It will only happen in first year from a complete stop and it’s even worse starting on an incline. The chatter will only happen between 1100-1900 rpm. And before anybody says it, yes I did properly clean the friction surfaces before I assembled everything. I really don’t think that would be the problem because if that was the problem the chatter would have started the first drive, not a couple months after the fact. I’m thinking that the problem could be a faulty pressure plate (fingers on plate weaken when heated up, therefore applies uneven pressure), the reuse of the bolts on the clutch assembly, or a faulty flywheel (flywheel warps when hot) which in my opinion is the least likely. Anyways I’m not in a hurry to fix it I knows how to work around it. However, any ideas help.

 

Most chatter situations I’ve seen are from the springs in the disc. Oil contamination can be a cause too. Other things could be a bad plate or I’ve also seen many not change the pilot bearing because they couldn’t get the old one out.

 

My '84 chattered for years, and it turned out being the slave cylinder leaking fluid onto the flywheel and clutch. Seeing as how you already did that (and assuming the new part didn't fail), the throw-out bearing comes to mind.

That there was no issue and suddenly an issue would have me looking at the slave again to see if a seal blew out, just thinking out loud.

 

What kind of clutch did you use? Years ago I replaced my stock clutch with a Spec Stage II on a 4.6 I had and it chattered like crazy after about 4k miles or so.

 

Most likely it is from oil, coming from the engine rear seal.