I recently finished installing M20 tranmission into my 69 442. I had a new bushing and seal put into the tail stock. I also had new universals and the drive shaft balanced.

After installing I noticed that at higher RPM's (greater than 3000) I get a bad vibration. If I engage the clutch in goes away. The vibration is also more noticedable in 1st and 2nd gear than 3rd or 4th. The vibration also becomes less noticeable once I have driven a little ways.

Any thoughts?

 

I had the same problem in my Vette, a new Ram pressure plate did the trick, their balanced at the factory. Is your engine balanced? If so is your pressure plate also balanced to the engine? If not thats likely the problem which can be resolved by having the pressure plate neutrally balanced. And if its a used pressure plate you may need a new one or have it neutrally balanced depending on your finances. If none of the above apply then maybe they need to look at your drive shaft again.
Steve

 

Thanks Steve

I am new to the oldmobiles so I don't have much knowledge on the engines.

My car has a 455 in it. The car was orgianlly an automatic and was converted to the 4 speed. I know that the fly wheel is new, but I will have to look into if the pressure plate was used or new.

 

Was the bell housing checked to make sure all is centered?

 

Eric

I never confirmed that is was, but that previouse owner stated that he did.