It's a company called GRB Co. out of Gardnerville, Nv. Part #1050 Type R Lithium Diff Lube. At least that's what the label on the container says. Good luck finding them because I think that they are extinc. The key word is lithium and it's red. Smells a little like the oil waste tank at Schuck's.

Slapmaster Tools now has Niftech diff thrust bearing kits, #109

I would claim that I have this fancy rapid proto-typing machine out back... but I just move the cut off bit over a little