I had my new Spec Stage II clutch and LT4 PP installed a few days back. Now prior to clutch install with my 4.10 gears which were perfectly smooth until highway speeds (stock steel driveshaft) and car was very smooth on acceleration. Now after clutch install I have bad vibrations very noticeable in first and second gear during about 70%+ throttle. Obviously I am breaking in the clutch properly but this vibration isnt normal. The only part that changed really was that im using a different flywheel out of the same year car which I did have plained BTW. Even though im still using the steel driveshaft I dont see how it would cause the vibrations to be soo much worse just because of a new clutch. It also seems that the car vibrates unusually during only revving pointing towards possibly the flywheel.
Anyone else have any thoughts on this?

 

Your flywheel may not be balanced.

 

I really need some help guys. Pilot bearing was checked and was perfect condition. I talked to a guy tonight that said since I am using a completely different flywheel, new PP, and new disc that I might need to have the entire assembly balanced all together. Anyone have anymore ideas???

 

Why does everybody say they use the spec clutch with the LT4 pp? When I replaced my clutch, I just ordered the whole assy. from lgmotorsports, bolted it up to resurfaced flywheel, and no prob whatsoever! Could it be that mixing and matching parts is not good, maybe they are supposed to be balanced together, as stated above??

 

STAR says their PP is the same as the LT4 PP you can get from SLP, GM dealer, etc. only they paint it (red, yellow, blue, etc). So technically its not an improper match up. I have the same problem, but it developed some time after the clutch install. I'm going to start with replacing the DS and see what happens. Spec stage III disc is coming very soon also.

 

OK. Mine is painted bright yellow. I guess it probably is an LT4pp then. As far as the vibration, could the flywheels be balanced to an individual engine, and swapping them could cause imballance?

 

Yes the LT4 PP is identical to the PP that comes with the spec setup (except costs less when bought seperately
I was told that the clutchs are not balanced to an individual engine however the PP and clutch disc are balanced together. Im not sure about the flywheel however. I am going to look into getting my pp and disc balanced together. I have an aluminum driveshaft on the way and hopefully (but doubted) that will fix or atleast help fix the problem. Dont think it will because problem started right after clutch install so it has to do with those 3 parts, flywheel, PP, Disc.
Anyone else have any input?
Thanks