Why trans/driveline 'clunks' when I put in reverse? '87 TBI 350 w/700r4

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dvdswan

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There was a TSB way back when, for the GMT 800s for a driveline clunk. Slip-yoke was binding. R&R driveline, clean splines on driveline and t/case or trans (4wd/2wd) and apply a light coat of grease.
 

Jwernatl

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that's good - wonder if i can find that?? hmmm....
 

Jawzjeep

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I was going to point out what Dvdswan said. In my situation I would use the brakes to stop moving. Still holding the brakes, shift into reverse, start to back up and clunk. When I hit the brakes the nose dived which extended the rear drive line at the slip yoke and when I finally came to a complete stop the slip yoke was bound up tight. (Still holding brakes). As soon as I let off the brakes the binding let loose and the slip yoke went back to a non binding neutral position. That bind can happen with a slip yoke or even the slip portion of a standard shaft with the slip built into the shaft. Might try pulling the rear driveline to eliminate it as the culprit. Ive also seen the drums move on a semi float rear. Hope this helps and/or you find your problem. Good luck.
 

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