My truck was stolen and recovered, rear end was missing. Body shop installed rear end out of junk yard (re-built, supposedly) comes with 90 day warranty. After 60 days, I wanted to service the rear end, to not only add Synthetic fluid, but to also peek inside. When I got a glance of the diff, something struck me as strange, holes in the diff!!!!!!!! near the bearing on the passenger side of the diff. I can see the spider gears peeking through. It looks like the spider gears are wearing through the diff, even though the rear end is NOT making any noise driving down the road. So, I am not sure if the holes are supposed to be there or not (I know there are a few open area's on the diff, like where the cross pin goes through, but this is on the face of the diff, close to the diff bearing on the passenger side, near teh main cap that holds it in place) . So, if someone has pics of their diff that they can post here on the board, or email me with pics, it would be greatly appreciated, as I have 30 more days if in fact there is something wrong with my diff. Or, if someone has a link to pics of the diff, that would work as well. I went to the dealer, and the pic they have I could not tell.

03 Dually. Need help, THANKS!

derrickm @ sbcglobal.net

 

I do not have a pic but I can tell you that after pulling the cover to change the fluid on mine, I found the same thing you describe. Must be machined that way for clearance.

IIRC, there is a pic of the rear end innards around here somewhere.

 

Right from AAM they are machined that way for fluid flow to allow even cooling.

 

OK, thanks guys. I saw that, and I have seen MANY diff's, and have never seen that before. The thing is, it does not LOOK like it is machined, ya know??? Just looks like metal rubbing through metal. Oh well, thanks guys!