[elecblue72]

i have a 72 gto with a 400 4 speed 355 rear end. from the day i got this car it has had vibration and i can not figure out what it is. i have changed transmission, drive shaft, the whole rear end, tires and rims, and the problem is still there. it is not in the front. feel it in the floor mainly in the shifter. anyone out there got any ideas or suggestions.

[getmygoat]

Originally Posted by elecblue72

i have a 72 gto with a 400 4 speed 355 rear end. from the day i got this car it has had vibration and i can not figure out what it is. i have changed transmission, drive shaft, the whole rear end, tires and rims, and the problem is still there. it is not in the front. feel it in the floor mainly in the shifter. anyone out there got any ideas or suggestions.

How about your cross - member? Is the frame in good shape where the cross member bolts up? (sometimes if the car is jacked improperly at that point it can bend the c-channel) Does the cross-member hold tight when its bolted down without the trans resting on it?

What about the tires/rims on the back? Have you swapped out a friends tires/wheels to see if anything changes? How about the brake drums, did you swap those with the rear?

Since its in the shifter, what about the flywheel/clutch? - Pilot bearing? - Does the car shake when engaging the clutch in first gear (from a stop)?

[LPete]

Is it engine-speed or vehicle-speed related? Does it do it with the engine sped up, sitting still, or only with the vehicle moving? If moving, at what speed does it happen?