Hi,
For a year and a half I have had some clutch chatter in first gear, when I drove the car on the freeway, the clutch would normally warm up, and when I stopped at a red light, it would chatter. I first took it to a trans shop, who did a complete clutch replace...but after a few months...same thing again...so I took it back and they completely changed everything...so they said..but months later, you guessed it chatter, took it back, and they did not know why, so I tried everthing suggested on 3rd. gen., and then took it to the best clutch/trans man in town. The problem was the FLYWHEEL...the other trans man took it to a machine shop, who grossly undercut the flywheel...so the new trans man put me in a new flywheel. I talked to a reputalble machinist, and here is what he told me....said that most people who cut flywheels to restore them do not know what they are doing...will cut it with a regular cutter DRY, many try to hury the job becuase they are paid per piece, and this is where the real problem comes in...it is not perfectly machined, and it causes clutch chatter. Here is the secret he told me he does when machining.....he uses oil to coat the flywheel to prevent overheating and uses a
DIAMOND cutter which cuts it slow, but PERFECT. He told me he also does heads that are refurbished by others and same thing, it is usually wavy till he cuts it with the diamond cutter. Anway, even though you may get the clutch put it by a reputable clutch/trans person, make sure you do not buy a remanufactured flywheel, unless you have a pro machinist check it out before you put it in...or better yet, just put in a new flywheel.
It took us a long time to figure out what it was, we checked everything like leaking seals/motor mounts, etc.
Hope this helps someone out there....it is so nice having my Z28 run great!
Dennis