i got a 84 z28 305 auto with 82000 miles on it. when i put it into drive or reverse (if it catches hard) i will hear this knocking noise that sounds like its coming from the driver side rear end somewhere. it doesnt do this all the time. it will also do it sometimes over bumps. the car drives fine, no vibrations and pulls hard. i havent got a chance to really inspect underneath, but someone told me it could be the u-joints. could that be it and what else do you recommend i look at? thanks.

 

Look at the U joints. While you are at it, why not take the driveshaft out altogether? That way you can see if the joints are good. They should move smoothly. If it feels like there is a notch there, replace the joint. Also, you could put it on a balancer to make sure it is not bent and in balance. Also look at the tranny mount. That is on the crossmember. You take the DS out and jack the tail up. If the tranny seperates from the crossmember, you need a new mount.