Help W/Noise

Hi All,
OK, I know this is a hard questions to answer, just as it is hard to describe. I have a 72 Chevy Burb. I do not know if any work has been done
to the rear end, but I do know that I replaced the tranny and the engine. When I bought the Burb it made a strange clunk clunk noise from the rear of the truck. My first thought was that it was the rear end, but I was going to be doing some work on the drive train so I figured I would wait to see if it went away with the other work I was doing. Like I said the engine and tranny are new and the drive shaft has also been shortened to accommodate the longer 700r4. Everything is in and working fine, but the noise is still there. The strange thing is that it only makes that special noise when I am at a dead stop and starting, and only when I am turning. It has never made the noise from a dead start if I go straight.
Any help would be greatly appreciated. John San Diego, Ca
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wrote:

The drive shaft slip yoke could be a tight fit and it's binding up. When you stop in binds in one direction, and when you start it unbinds with a clunk. My 76 Blazer used to make a noise like that all the time.
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if I remember correctly that rear has C clips that hold the axles in. The clip and washer that it rides against could be worn out. moving outward on a turn from a stop. it also could be the rear brakes are hanging and release when you start off. GM had a problem with this in some years for trucks. check the c clip and turn the rear drums and see if that works.

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Sounds like posi-traction clutches releasing to me. I've seen it cause wheel hop on a tight turn if they don't release properly. Try changing the diff. lube and putting in the anti-slip additive or go buy the high-dollar gear lube that GM sells (used to sell) for that application. You may need to change it twice if it has been running with 90W or some other non-posi lube. If you don't have posi-traction, forget what I said above, but it's still a good idea to get new gear lube into that old unit. Good luck!
Martin
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If its only on turning take a look at the tortion bar mounts. If you can lift the tortion bar crossmember off the frame with a jack the mounts are shot.
M. B. Lee wrote:

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