Hissing/dragging mystery noise from rear end, stumped!

[MoreMayhem]

as far as I know the automatic cabrios came with 4.10 open diffs, there might be other difes on different year models,
mine is a 1991 plastic bumper automatic
Henry

That makes sense. I'm 5 speed.

-MM

[Eddie Haskell]

Could be brake pad drag. If the sliders are sticking or if the caliper piston seal is sticking to the piston (stuck corroded bore) the pads will drag on the disc. Happens frt and rear. The rears are easy fix. If Girlings on frt. Pita. There is a technique for the piston gaiter on Girlings. If u dont follow you will be chimping, Grasshopper. Seems as though disc runout would alleviate the problem but sometimes it dosnt.

[jeffnhiscars]

4.10 open here as well.

Before I started replacing anything other than the diff oil, I'd take a close look at the e brake. If its adjusted that poorly who's to say it was installed right. It's not uncommon for the shoe retaining pins to corrode or pop out which could easily cause a noise such as you describe.

[jlevie]

A dragging/scraping/hissing noise from the rear wheels that doesn't go away with application of the brakes or parking brake won't be from dragging brake shoes or pads. It could be from something in the parking brake mechanism, which should be obvious once you pull the rotors. If not from the brakes or backing plates, the next most likely cause is a bad wheel bearing. A bad bearing in the differential is a possibility, but I'd change the wheel bearings before messing with the differential.

[Bigboy740il]

I feel your pain OP. I have the same noise and have changed the diff fluid, wheel bearings rebuilt calipers, changed brake lines, and still have the same noise. My next step is guibo and center bearing, and if that doesn't work i will change the differential for another.

[sweet3]

Same issue here. Changed rear wheel bearings, diff oil, rear brake pads and rotors, e-brake shoes, center support bearing and still have a noise :/

[goldenbb]

Please keep this thread going! I'm concerned about a similar sound--it speeds up and slows down with the car. Rear rotors and brakes are brand new. Haven't looked at the e-brake, but I don't think it is too badly out of adjustment. I replaced a front wheel bearing, so I am suspicious of all the bearings at this point.

The guy I bought it from was not entirely truthful about its condition, so if something major were wrong like the rear diff, that kind of fits why he was selling it.

[cabriodster87]

My diff sounds like a swimming pool pump.

[Wanganstyle]

If the whine is related to LOAD and throttle position and will still make a rumbling in neutral while coasting in neutral...............


usually the diff pinion RACES x2 will have worn and the 2x related bearings are dying.
the entire load of the car is put on these 2 bearings/races.

a slight amount of metal in drained differential oil will show this;

[mr.vang]

Unscrew the axle from the diff, start the car and put it in gear while its on jack stand. If its still noisy, its the diff. If not its the wheel bearing.