So I really got a lot of slop in the rear axles. Got a funny clunk in the back I'm also trying to fix (Spoiler Alert: The new spiders didn't solve that).

Anyway slapping in this kit. It's a middle of the road re: price:

 

Ta-da. They give you 3 sets of shims so that's helpful.

 

Including a comment about that little bolt that holds the pin in. A previous poster rounded it off. Let me just say that you need a quality 6-pt. 5/16 socket or wrench to take it off. I can see if the fit is a little loose it's easy to start rounding that thing off and getting in big trouble:

 

Ring gear backlash can be adjusted with those side nuts held in place by the small bolts on the outside edge of the carrier assembly. It looks like the tooth wear pattern is perfect, but is full face showing wear.

USA Standard Gear is a quality supplier that you can trust.

 

Well that was hard to find!

Turns out that because of the lift (although only about 2 inches) the rear shocks are now at a slight angle on the upper shock pins. The bushing wore on one side and the top of the shock was hitting the shock housing.

 

Backlash was .006 when I measured it last time I changed lube. Didn't bother checking this time but felt like .006. Maybe .007.

 

Okay. Didn't know how much you knew about diffs. I had my transmission rebuilt in a shop and they asked me if I wanted my leaking pinion seal replaced while it was there. I said, "Yeah, if you know how to do it right." They looked at me like I had 2 heads. The day I got the jeep back, the rear axle blew up, which they fixed. Even the carrier was busted.

 

Might be a stupid question but, having never done the 8.25 yet, if the backlash is set by the adjusters, what do you need shims for? assuming you mean carrier shims.
Most I have seen the backlash has been fine, because when you torque the adjusters it automatically sets them. Much trickier when you do a D35. Then you use the carrier shims.

 

No, because as noted, if you have adjusters, there's no need for carrier shims.

They are "Side Gear Thrust Washers".

 

#18:

 

That wasn't it either!

The shock itself had failed ("failed" being a loose term).

With the minor lift and and subsequent rear axle angle shimming, the shock needed to be pulled forward in order to be remounted on the bottom pin. This put a lateral stress on the plunger, causing it to make a clunk whenever I hit a bump. Oddly, I can't duplicate the noise with the shock out out of the XJ so I imagine they won't warranty it.

That, and the fact that the top mount is a little bent ("modified").