My 2006 Chev. Tahoe 2WD (125k miles) was making a bit of a swishing noise that seemed to be coming from the rear. I took it in to an independent shop specializing in rear end repairs for service and they found this and one axle end bearing that didn't look great but was serviceable.
What causes some rollers to be messed up and others to look not warn? It is amazing it didn't make more noise and breakup. Bearings are tough.
The diff. is a Gov Lock (Code G80). The guy said they break and I should replace with a limited slip at some point. I think the best replacement is a "gear" type diff. e.g. torsen truetrac.
They replaced all the bearings in the center area and installed new seals at the ends of both drive shafts. $560 later I was out the door.
