ars1

I had the clutch/flywheel replaced in my 94 5.0 and when I got it back I noticed a vibration at > 4k rpms. Then I started to hear a grind when I let out the clutch so I took it back and the throwout bearing was missing the retainer clip. So they replaced the throwout bearing and now it doesnt grin but I still have a vibration > 4k rpms. What could be causing this? I never noticed it before the clutch/flywheel being replaced! I also had 2 flowmasters with dumps installed at the same time.

How do I check the u-joints?

ars1

Talked to the owner of the performance shop and he said there is a 500mile break in period on the clutch. Would this matter?

Bubba 95SN

I doubt it will go away in 500 miles. May not have put driveshaft back on same place on pinion flange. Go on 4 ways, one correct.

mjr46

who , knows what flywheel they used, may have the wrong imbalance

mattdel

I would think an imbalanced flywheel would vibrate full time, no?

I'd be looking at driveshaft imbalance.

02WhiteGTVert

Was the flywheel resurfaced? If it wasn't, that'd be my first guess. Second, Check the driveshaft bolts. Always use blue threadlocker on them, Everytime I reinstalled one without threadlocker the bolts eventually backed out. The retaining clip is on the clutch fork, not on the throwout bearing itself....Also,did they install a new pilot bearing when they did the clutch? If they forgot the pilot bearing, it'll vibrate like a bitch at higher RPMs.

AdderMk2

any vibration that is purely RPM based, will NOT be caused by anything after the transmission.

I'd lean more towards a slight imbalance of the pressure plate, OR since the TOB was installed incorrectly, it could have messed up one of the release fingers on the PP.

ars1

It is a new flywheel but I bought the parts from advanced auto parts.

mjr46

that doesn't mean much...new doesn't mean correct or okay...btstdt........

ars1

I did some more testing with it today and I have noticed that the vibration goes away alittle > 5k rpms and if I bring the rpms up slow it doesnt vibrate. Only under a load. In neutral there is no vibration even reving. and it seems to have lost a bit of power. Is it at all possible that the used flowmaster 40s dumped before the axel that I had installed at the same time as the clutch could be causing this problem? The car has 2 cats deleted and the other 2 are hallowed out from what I understand.