I am going crazy here. I boiught an 86 transam for parts with a "perfect" 5 speed and i wanted to put it in my 86 transam to replace the auto. After evrything was swapped, i noticed a vibration starting at 2000 rpm and increasing with engine speed. This is a "new" clutch, pressure plate and bearing in the donor car for about a month. It actually does look pretty new. my first assumpsion was the fly wheel was warped. put a new one in. started the engine with only the flywheel bolted on no tranny or clutch ***. Smooth as a caddilac. Problem solved? No. reassembled the tranny into the car and still a vibration with the car stopped, in neutral and the clutch pedal to the floor. The pedal feels a little chattery when releasing it in gear to take off. I know this is a novel but there are most of the details Please any suggestions.

 

did you put a pilot bearing/bushing in the end of your crank when you did the swap?

 

who'd of thought of that. that was going to be my question until i read your reply.

 

Yeah. a brass pilot bearing was already in the crankshaft.

 

you don't know if the problem existed or not in the other car before you swapped the partsd over do you?

 

alright, but unless this motor has had a standard trans on it before or atleast the crank your using was once used with a stick it shouldn't of had one so you are sure? just checkin

 

Okay here is a bit more info. The donor car is an original 305 ho 5 speed, the car I drive is a built up 350 with nothing origional in it. I asked around home here a bit and two people have told me to try the 305 harmonic balancer on my 350. Are there any balancing changes gm made i need to know about? i am 99.9% sure a 305 and a 350 crank are the same-at least up to 1987.
Help me!!

 

The crankshaft i bout fromthe machine shop and it must have been in a stick car before trade in.