rotonomo

In my daily drivermobile 89 GXL I get a wierd thump from the rear end under breaking. Its not like one thump and goes away, but seems to coincide with the rotation of the wheel, leading me to believe it was the rotor. I checked the rotor, it is not cracked but had a bunch of scale that was like 1/32 inch thick where the pad had touched the rotor over the past year of not moving. Would this cause the problem?

Also, how would I check for a worn bushing? Can I just wiggle the rear end parts around by hand and if they feel good run it? Or do I need to pry somewhere?

This car only has 88k miles on it so I dont think its a worn rear end component.

Oh its a 5 lug too, in case that matters.

HAILERS

Thumps when stopping? How about when taking off???? Sounds a lot like the differential mounts. They're cheap in relationship to the cost of a bar of gold. You can check that by jacking up the whole rear end, putting the car in second gear with the engine running, and observing the front of the differential when the brakes are tapped. Broken front differential mount is identified by the nose of the differential rising up over an inch. The rear mounts: you might take a wrench and see if the nuts for them are tight. Small chance it could be the ujoints. While its jacked up, grab the top and bottom of each wheel and alternately pull and push on the wheel. No play should be there. Do the same with the front and rear of the wheels. Absolutly no play allowed. Another small chance: could be your spare tire is not tied down and its flopping against the bulkhead making the noise.

Felix Wankel

Try to sand the scale off the rotors. That might be whats making the noise, especially if its under braking only.