Rearend EXPERTS HERE!! *pics*

I had rear gears installed about 5 years and 8,000 miles ago. About 3,000 miles after the install I remember hearing a grinding noise ONCE when I backed up. I waited for it to happen again, but it never did. Time went by (about 1,000 miles) and I noticed the rear began to get a whirling noise to it.

Now in present time the rearend has been howling something fierce. Every time I drive the car it gets louder. I figured it was a(the) carrier bearing(s). Well, I had Moser axles, an FRPP diff and 3.73 gears installed today along with all new bearings.

It turns out the driver's side carrier bearing is shot. The cone and rollers were majorly tore up. In the pics you can see the cone. It ONLY has marks on one side of the cone. About half of the cone is marred, the other side is fine.

What would cause something like this? Just a bad bearing or a bad install? I dont understand how a bad install would only eat away one half of the cone. I had my local Ford dealer do the install since I have no experience with rears. The new setup is so dead quiet that the car seems like a total new beast. I can actually hear the radio now

<img src="http://www.mustangmods.com/data/393/p5181228cone1.jpg">

<img src="http://www.mustangmods.com/data/393/p5181232cone.jpg">

<img src="http://www.mustangmods.com/data/393/p5181235bearing.jpg">

87'GTstang said:

Those rollers are beautiful
Is that foreign material, worn down metal particles, or gouges in them?

Click to expand...

The black spots you see are the gouges. I think it had to be a bearing defect to cause such a problem. It looks like the cone failed and then the rollers got ate up as a result.

I dont think improper cap installation or applying too much torque to the main caps caused the problem b/c then both sides of the cone should have been destroyed.

I guess something could have got in the bearing, but I just dont know what and it would have to be super hard.

87'GTstang said:

How much fluid was in the rearend? Was it changed after the break-in period and was it broken in properly? It looks almost like a defect in materials or a poor installation in a way.

Click to expand...

The rearend was full. The fluid was not changed after the install, but it was broken in properly.

The caps were installed correctly too because the arrows were pointing to the outside, just as they should be. They were not accidently swapped.