Rear End Noise Help

[S/CBlack95GT]

About 4 years and 8,000 miles ago I had Ford install 3.55s for me. At the time they were super quiet. As time went by I noticed the rear began to have a whirling noise. Now in the last 3,000 miles the noise has become very loud. It is most noticeable when I let off the gas. When I take long sweeping right hand turns, like when exiting an interstate, the noise becomes much louder. Something about the weight transfer to the left makes the sound louder. Does anyone have experience with a problem like this and could you give me any pointers on things to check? Thanks.

 

[fordman54935]

It sounds to me like the differential carrier bearings are shot. The rear end in my 93 LX 4-cyl was making similar noises (included the part about sweeping right hand turns). My car had about 115,000 miles when the noise was getting bad and I fixed it. I'm not sure how much experience you have with rear ends, but it really isn't that hard to fix (I had a local machine shop press new bearings onto the carrier). The new bearings costed about $70 including having them pressed on. The trickier part is reseting the ring/pinion backlash, which requires a dial indicator and magnetic base. I was lucky with mine because I reinstalled the shims in the original places and the backlash was perfectly within spec.

The first thing you should check is the backlash, which will be thrown way out of spec with bad carrier bearings. Also check both sides of the gear teeth to see if any bad wear is occuring. With my car, I was honestly shocked because the gear teeth looked brand new.

You'll be able to tell if your bearings are toast by looking at them, as on mine the outer races had A LOT of abrasive wear.

Hope this helps!

 

[S/CBlack95GT]

Thanks for the advice! The carrier bearing(s) was exactly what I was thinking, mainly b/c of the sweeping turn issue. I recently replaced the fluid in the rear and the gears looked great. I even checked the mesh and it was fine, a perfect cigar shape in the middle of the tooth. I am moving here soon so I hope the bearing(s) will last another 1000 miles before completely going.