differential grinds when I turn

You have to start by opening the diff.

I actually had what sounds like the same issue when I removed a sorry BB and lowered my TJ 3 inches. In addition to all the spacers that come with a body lift, you apparently have to adjust the 4x4 shifter control arm next to the transfer case. What's happening is your 2H is actually partially shifted into H4. Adjust the nut on that control arm: If you are under the jeep with your head towards the engine and your feet towards the rear, the shofter arm is to the right of the transfer case.

sometimes low fluid will cause a limited slip to make weird noises, and just topping it up solves it. I can get the friction modifier at carquest, but haven't ordered any since they became a Napa store.

Thank you all for the replies, I will follow up on all your suggestions.

When my TJ started doing that, it was the Dana 35 rear end self-destructing. One of the carrier bearings spun and then wore down the spacers allowing the carrier to contact the bearing caps. The noise was more apparent when cornering. Once it was at this point the only thing to do was replace the axle as the case was too chewed up for rebuild. Luckily some moron totalled an '05 Willys at only 500 miles so I have a nice new axle now. Too bad it's another crappy D35 :(

Shawn

John North Willys began production with the Willys-Knight in 1908, and Willys Corp. was sold to Kaiser in 1953.

You're asking me? The OP has to decide which is making the noise, then open it.