Bad noise from rear.
 

I had this very bad noise coming from the rear. I left the car to a car repair shop and past them today, talk to the tech working on my car. He had replaced all bad bearings and he is telling that i dont have original stuff in the rear. It is 3.42 gear (my is auto). Since i´m the second owner in Sweden to this car (2003) and i know first owner didn't do any kind of work, this has to be done way back when car was still in USA( Birmingham AL). Since we couldn´t find any labels with brands stamped so i'm asking the experts.
Is it possible to see what kind of stuff is in the rear? Does this look like original GM or aftermarket?

https://ls1tech.com/forums/attachmen...1&d=1277375555
https://ls1tech.com/forums/attachmen...1&d=1277375555
https://ls1tech.com/forums/attachmen...1&d=1277375555

All looks stock except the carrier bearing cap studs, stock they are bolts. That is the factory Zezel Torsen Diff. He may be used to the standard diff.

Just tell him that the WS6 is more then a hood....

If they are original GM OEM gears (sold directly to GM) I believe the ring gear should have a GM-###### (part#) stamped into the ring gear. You should be able to see the part# somewhere on the flat surface to the left of the ring gear teeth as seen in your 2nd picture. As the previous post stated someone installed studs instead of the original bolts, which is not a problem. I believe AAM was the OEM supplier for GM ring & pinions and they still make gears to the same OEM spec. for the aftermarket but they do not have the GM part # on them.
Good luck.

Thank you. One other issue was all 4 bearing cap studs was loose..........