I have been hunting a vibration for sometime now and I seem to have found it.
I pulled the driveshaft and ran the car in gear, vibration.
Pulled the trans out and put the empty T-5 case in the car, vibration.
Pulled the case, bellhousing and the clutch, no vibration.
It’s so smooth that I knew as soon as I started the car up that the vibration was gone.

Now here is the question, what’s the problem?

Aftermarket T-56, ZZ4 with a GM flywheel (16lb nodular iron), Centerforce dull friction clutch, pressure plate and throwout bearing for the T-5. They are all new parts and the pressure plate and flywheel look good, no hot spots and both are flat.


I did find this, but the pressure plate does not have a yellow dot on it and it’s about the 4thgen clutch and I am running the thirdgen clutch.
http://128bitencrypted.com/centerfor...s/I94GM004.pdf

i guess you could call a machine shop and ask em if they would compare the balance of your flywheel with a known good one....


ZZ4 is a two piece main with a external balaced flywheel right? perhaps the off balance is "wrong"?

The ZZ4 is one piece main seal and uses the same flywheel as all the one-piece motors.

Besides with just the flywheel on the motor it's really smooth, it's just with the clutch and pressure plate on there that it's vibrating.

The clutch assembly is out of balance. I'd see if a machine shop can balance it. If they can't I'd send it back and demand a replacement.

That's probable what I will do, still it's brand new and it's not cheep so it should not need that done to it.

Thanks for the reply