In my younger days, I always had a tire wear issue with the right rear tire. I'm not sure what the cause was, but I suspect part of it was because when I did a "hard slow right hand turn", under power, the ride had a tendency to lift the right rear a bit, taking weight off of it causing it to "scuff" (squeal, spin, or smoke) more then the left rear tire would.

You realize when you go around a corner, the tire on the outside has to travel farther then the tire on the inside of the corner. A locked or semi locked (limited slip) rear end tends to match the speed of the inside tire to the speed of the outside tire, resulting in the inside tire spinning just a bit.

On my 4x4 you can feel the truck bind up until a tire slips on a tight slow turn.

It might help to change the gear lube in the axle and add a fresh can of Friction Modifier (posi lube), then find a parking lot and do several slow figure 8s. The clutches might be getting dry in your rear axle. Gene