Doing a little work over the winter. 1987 Formula Firebird TPI 5-speed. The old clutch worked ok, but there was a vibration at about 2000 rpm. Had a long time GM mechanic suggest that it may be the clutch so I ordered a new one. New Centerforce pressure plate, disc and throwout bearing. New flywheel, new clutch fork and pivot ball. Even a new slave cylinder. Got it all buttoned back up and test drove it and immediately knew something wasn't right. Clutch pedal is almost all the way to the top before the clutch engages and since it's hydraulic there is no adjustment. Clutch does not hold well, wants to slip. I followed Centerforce's instruction and the Pontiac factory shop manual in detail, everything double checked. I'm stumped. Anyone got an idea? This won't work.

 

Check with centerforce but it sounds like you have too long of a TOB. Did you compare it to the old one? Other possible thing is does the clutch have a bent finger(s)

 

After talking to technical support at Centerforce, I pulled the transmission and clutch. Half of the pressure plate bolts had noticeably less pressure on them. Pulled the flywheel and rechecked everything again. Reassembled the clutch out of the car, and half the bolts take little resistance as they take up the pressure plate load. Looks like the pressure is bad., not loading the disc evenly. This is a new flywheel, pattern is all wrong.