1996 gc loud clunk

[modman84]

Hi to all , this looks like a great forum and I have a quick question. I have a 1996 gc V8 with 143000 miles and when I am backing up and hit the brakes I get a realy loud clunk. it only bothers in reverse and when the brake is applyed. it feels like the rear end is going to fall out. any advice would be greatly appreciated

[Ron68]

Check u-joints. Rear wheel lug nuts tight? Rear wheel brake calipers tight? U-bolts tight on axles?

[RBrandon]

I agree with the first responder on the u-joints. Could be slack in the differential but not as likely as the u-joints with the mileage you noted. One test for u-joints is simply shifteing between reverse and forward (while holding the brake) Effectively what you describe. Let us know what you find.

[modman84]

Hi thanks for the input . here is some more info have checked u joints they are good have had rear cover off and ring and pinion seem fine brakes seem fine. this clunk is only while moving in reverse and then hitting brakes here is a thought could it be upper control arm bushings loose enough to hit body when brakes are applyed in rev ?