I heard some mention of different flywheels for different year LT1's.
Right now, I have a 93 T56 setup that I am going to use with my 95 LT1. My brother needed a tranny temporarily while his Auto gets rebuilt so we put my T56 into his 96 Trans Am and the car has a crazy vibration.
Doesn't matter if the car is moving or sitting still, give it some gas and the car starts to shake.
He just had his motor rebuilt and we didn't notice any vibrations when he used the Auto tranny
His auto will be done in a week or so but I want to try and figure out what is causing the vibration before I put the tranny into my car, assuming it is tranny related and not the engine.

Possible causes could be one or more of the following:
Balancer/Dampener
Clutch disc
Flywheel
Input shaft of the Tranny

any tips or advice are really appreciated.
thanks.

 

AFAIK, there's no difference in the flywheels.

When you put the T-56 into your bro's car, did you balance the flywheel to the flexplate?? If they were balanced differently (very possible) then it could easily be your problem.

That's where my money is.

 

i have a 93 t56 on my 96 and all is well. other than the lack of the skip shift i think it is the same. other than the gearing

 

Actually I guess I could have mentioned this too. I have a 95 T-56 in my PP 93 car.

 

Well, his car was a Manual to begin with.
He swapped his T56 for a 4L60E.
The T56 setup I have came right off of a 93. Only thing I did was have the flywheel resurfaced.

My LT1 originally had a 4L60E attached to it and I believe I still have the flexplate that came with the motor.

I was thinking of just buying a new Flywheel since they are only $45 with your old one.

 

did the flywheel you put on his car have drill marks on the backside of it. if it did it is already balanced.

 

I don't remember. It's coming out next week or the week after, just waiting for the 4L60E to get finished.