92 Firebird. Complete 305 to 350 swap. Everything new, lol. Help!!!

When I accelerate I get a mild vibration and HEAR a wallering around sound somewhere in the drivetrain. Ujoints replaced, tailshaft bushing and seal new, tranny mount new, etc. Drive shaft checked using the "EVA" machine or system. Checks for balanced drive shaft. Looks great! Again, I am wondering if the tranny mount is an issue.

Yes I have done the "search" for 2 hours. Its clearly a 50/50 it seems like. Some say not a problem others say yes that the aftermarket tranny mounts cause a problem. Guess it throws off the pinion angle. Well, the vibration/wallering around sound was there prior to the conversion and modifications. Thus, with the factory mount in place.

Any ideas? Thanks so much.

 

i believe i have the same problem somewhere cruiseing around 2500 rpms and above i get this wallering sound and feel it through the shifter. the faster i go the faster the sound and when i let off the gas it becomes worse until im doing about 40 then it goes away.

it was also there when i bought the car. so far the motor, trans, trans mount (poly), rear,rear suspension, has been changed but no help. i was also thinking the driveshaft because that is the only thing that has not been changed besides the front suspension.

 

Well, my problem exists only at lower rpm's. The faster I go it seems to smooth out. Now when I am around 85 and above I do have a little bit of a vibration, but I suspect suspension and not drivetrain.

I took my car to the dealership and the performed the "EVA" test on it. It tests the driveshaft. That may be an option for you.

Good luck.