This vibration, could you be feeling something "grounding out" as in a exhaust pipe hitting the floor boards while under a load? Trans case hitting in the tunnel. Like asked before where do you feel it Steering wheel,seat or whole car feels like a big vibration? Also check the rubber insulators on each end of the trans cross member where it bolts to the frame.
__________________
'68 GTO
'69 Corvette
'75 Cadillac Coupe Deville
TOM
|