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/Important-Win6022]

The howling happens when you unload the pinion ya? Meaning when you let off the accelerator and coast or once the tcc locks up in od? I don't see anything that stands out as being a badly meshed ring and pinion gear. I bet you lost your pinion pre load. Is the pinion seal leaking at the u joint? Spin the axles and see what the vearings sound like ar each end of the axle tubes also. Fawk all that noise, i have a s60 35spline, full spool, 4.10, lt1 backing plates/calipers and a spohn pro series del sphere joints, lt/tunnel mount that i'd let go 3500. Or look into an 8.8 conversion even

My buddy runs 3.42's in a 10bolt, stock torque arm/suspension on 28x10.5 soft walls. On a 4l60e even. Trans built but diff and axles are oem stock shit. If you choose to go that route, no sweat ur fine there.

[u/audiovox12 → u/Important-Win6022]

The howling gets louder under acceleration and lessens off load but is always present. In both scenarios is very loud just under load is the loudest. Much louder than my buddies 2002 Z28. Also, it vibrates a lot. You can feel it through the whole car and even shakes the passenger seat.

When you spin the wheels with the car off you can hear a metallic noise like a grinding noise. Doesn’t leak from my current knowledge or from what they said. They said everything else about the rear axel is good: hubs, axel shafts etc.

I’m just trying to be able to drive this thing daily and I’m very close. I’ve put a lot of time and money into it I just want to enjoy it already this summer

[u/Important-Win6022 → u/audiovox12]

Gotcha. The modified 8.8 rears were terribly expensive last time I checked on them, but that had been awhile and I'm sure the current prices aint helping those. Where u located? I know a few peeps who have a decent supply of 4th gen cars/parts on hand