Rear diff shim fell out

League · Jul 28, 2014

Hey guys I got a 01 f350 manual 6speed with 191000km on it and I just checked the rear diff oil and I found a piece of steel on the plug. So today I pulled the cover and found about half of one shim in there. Have any of you guys seen a shim fall out? And what do u think my best plan of attack is to getting it fixed take it in and get a total rebuild or just ad a the right size shim and see what happens? There was one chipped tooth on the ring gear right at the tip but other than that looks alright. Thanks

m j · Jul 28, 2014

what is the shim out of?
chipped tooth doesnt sound good
is the pinion loose?

League · Jul 28, 2014

The shim looks like it is out of the passenger side in between the bearing and the ring gear housing, pinion seems to b tight in there but I am no diff expert.

MoonShiner · Jul 29, 2014

Pull it out and inspect the bearings. I've built dozens of diffs and the only ones I've seen where there was a shim issue was a Jeep where the carrier bearing cone was loose on the carrier and had chewed up all the shims on that side.

The carrier bearings are a tight press onto the ring gear carrier housing thus holding the shims in place.
If everything looks OK, pull the bearing and put the same thickness shim back in....it will be fine.

I have a case spreader, but you might be able to remove the carrier without one......sometimes you can, sometimes you can't.

David N · Jul 29, 2014

Yeah if you're having shims falling out then your carrier has shifted one way or the other and it may not happen right away, but it will eventually show itself. And more than likely it will be when you least need it to happen. Having the correct backlash is very important in a rear-end.

I tooth missing from your ring gear is a good sign its time for a rebuild and a new ring and pinion.