I have a thumping noise coming from the rear differential of the car as I drive slowly (coasting or stopping). Sounds like it clanks or thumps with each wheel rotation.

 

Here's the key...when I put the car in Four-Wheel drive, the noise dissapears. I lifted the car - an 88 GL wagon - and had a friend rock the right rear wheel back and forth and the noise seems to come from the front part of the differential.

 

Thanks for any help.

Bruce:

 

I dont know why actuating 4wd would make any difference, but I had the same symptoms in my 93 Loy.

The solution was replacing the rear wheel bearings. I wouldn't jump to that conclusion until you ruled out some other things, but you should consider that possibility.

good luck, John

check the U-joints in the driveline going to the diff.

My 81 does a similar thing sounds like a mariachi band when I drive, I traced it to the U joints. Good luck

Maybe its a CV joint and when you put it in 4wd the rear drivetrain is no longer dragging but but just going the right speed so there is no load, therefore no noise? A bad-ujoint will generally clunk more rapidly than the tire rpm becaus of the diff ratio.