So i've noticed this since day one of new trans and engine. when car would shift from 1st to 2nd it would make a clunk noise. but when on it hard it wouldnt make a noise. also down shifting would realy make a loud clunk. passed it off as being the rear. well now that my motor is out i thought i would check it out.

when underneath the car tran drive shaft and rear are there just motor is out. with trans in park and when moving drive shaft there is a clunky/crunching noise coming from trans. this trans was just rebuilt for the 383 motor. is this noise normal or what could it be. I have another month before warrenty is up. I'm tring to wait to get the new motor in then take the whole car to the trans shop.

 

I broke alot of brand new built th350 on the street. I have one that made a noise so wierd that everyone and their mom swore it was a wrist pin in the motor. Rebuilt the motor to find it was the trans. I know that they are known for breaking the cases inside where the one of the drums locks in. I would def get it checked if you think its coming from there. Good luck