I have a 2001 duramax dully w/ ally. 4X4.
Got it used 1 year ago, over the winter I used the 4 wd 1 time and noticed
a noise when it was in 4wd. felt this in the steering wheel.
It has 40K on it and I wanted to change all drive oil's
Drained the front end down and when I pulled the plug no oil came out.
I stuck a screwdriver in the hole and all of the gear oil came out.
The first part of the oil was sluge, this gray, metal flake ugly looking stuff.
I would say about 2 oz. of the oil was sluge.
It goes in and out of 4wd ok, and when I turn the shafts by hand they feel fine.
It looks like I have a bearing going.
Anyone have any Ideas. have you seen this???