Unusual cupping right, rear drive. What's causing this?

Well I don't know if it's your problem but those wear pads absolutely are supposed to be on there.

I'm really surprised you had six alignments and no one thought to do that.

Those wear pads stop the spring from hitting the hanger.

I don't know that it would cause your problem but those wear pads do limit how far the spring can actually move.

Check your hangers to make sure they are not broken or cracked.

Here are some old ones. You can see how they wore.

 

I had the dealer check alignment plus 3 other shops until the one shop fixed the issue

 

It is possible that the axle housing is bent. The easiest way to check is to remove the differential carrier and install and tighten the axles. If the inboard ends of the axles don't align perfectly the housing is bent.

 

It is possible but if so the alignment(s) would have picked it up.

 

Call Mike Beckett at MD alignment out. He can tell you exactly what is wrong.

 

I think the tires just already started a pattern, and is getting worse quick. Bad shocks, low air, being mounted next to a larger diameter tire, all can cause or contribute to it. I call it step wear. Heel to toe, same thing. Used to g et it a lot running I 94, due to washboard road, worn shocks.

 

If the equipment that they used to align the rear axles used the
center drill holes in the ends of the axle flanges they would not catch a bent axle housing.