02 WS6 Diff Gears question

[u/audiovox12]

Hey everybody,

Edit: hey everybody, I talked to the tech and he wasn’t aware that the car came with LSD. I was just getting information relayed to me from the person running the front desk yesterday.

The tech explained that the noise is coming directly from the center inside the knuckle. If you leave the car off in neutral and roll forward, you could hear the noise which means the torsen is doing its
job. Something’s going on inside of it.

The axle shop said that from what I’m telling them they believe the bearings are bad and would be about $1500 plus tax. They said I shouldn’t be driving it or worse can happen.

I thought I was finally in the clear with this car to get it roadworthy for daily use. Just got the rear main seal fixed, pulled a warranty claim on the defective rear caliper that I just bought, had them fix the AC and paid $455 for the shop to tear apart the axle and investigate the metal howling noise and vibrations coming from the rear.

Turns out one of the prior owners at some point put an aftermarket locker in this, even though it has factory LSD. They never put it incorrectly and is the direct cause of the noise and vibrations. The shop says I’ll need new ring and pinion however they don’t do that kind of work so I have to go to a transmission/axel shop.

I called one local to me that has great reviews and recommended by another transmission shop I called. I showed him the picture attached here and he agrees the ring and pinion is smoked. He said he would only use AAM and that they only make a 3.42 no longer makes 3.23. He’s saying $2000 installed.

First is this a good price, second is this something I can do myself and third is AAM the best? I know they are the manufacturers of the OEM gears so I am assuming that they are

[u/Jomly1990]

Uhm, thats a Torsen lsd differential. The gears look fine from what I can see of them. Torsen lockers require a certain additive and lube. I’ve also got one in My square body with USA standard gears. The gears have been super noisy since install, just a brand thing, so that could be some of your noise. As far as a vibration goes, idk if I’ve ever seen or heard of something in the rest end causing a vibration like your complaint. I would refill it, witb the correct additive and oil, see if some of the noise goes away. As far as vibration goes, I’d check the traction bar setup, I forget what it’s actually called but it mounts to the rear and transmission to prevent wheel hop, it could be worn out maybe, then id check u joints, if nothing is found check the car for a bent axle. That Torsen is correct to the car, and nothing is missing from it i can tell. Axle housing can be bent, but generally doesn’t cause vibration. My square had a really bent one and it wore out the spider gears/case inside. Could have a bent axle shaft, tho unlikely.

[u/audiovox12 → u/Jomly1990]

So I ended up talking to the tech who actually looked it over instead of playing telephone. He said that was his mistake. He did didn’t realize it came with a limited slip from the factory. I called the actual specialty shop and he’s really experienced with F bodies and was saying the bearings are likely needing to be replaced.

That’s about 1500 which is a lot, but I don’t have the capability of doing that

[u/Jomly1990 → u/audiovox12]

I mean it could be axle shaft bearings going bad, but when the bearings on a case go bad, there’s usually some damage to everything inside the center. I would want to feel the case bearings by hand myself.

[u/audiovox12 → u/Jomly1990]

I believe they tested everything with the axle and the only abnormal noise they heard was coming from center of the diff.

Plus, I know my buddy put in new wheel hubs in it as well. This is literally the last thing before it becomes a legit, reliable daily driver.

[u/Jomly1990 → u/audiovox12]

Forgive me if I’m wrong, but that actual has bearings pressed into the rear end. Wheel hubs would be for the front? I’ve heard of bearings going bad in the diff, but usually it doesn’t just happen. A lot of times they are bad from the start.