Rear end hot rim to rim...

Relax bud. Can't hover over FABO waiting for an answer. It's a weekend and I have a life besides cars. I appreciate everyone's help here though.
Thanks for your replys. Details are its an 8.75" rear with green bearing, pinion has crush sleeve eliminator so that's not it. No leaking at axle seals as of yet. Only 30 miles on car since total rebuild.
So far no answers that explain it, unless the bearings are about to pile up, but why they would would make no sense to me.

Who built the chunk/carrier/rearend? As I said before the carrier may be stacked too tight if it wasn't set up correctly. That would mean the too many or wrong shims were used and that is causing undo friction that then friction causes heat.

I changed diff fluid last night. It was very dark grey.

You may have to pull that chunk and recheck the setup?

I think we are on the same page.