Stop in for a cup of coffee

I have removed a lot of diff covers. Never have i seen anything remotely close. I have seen total destruction and pristine diffs. This is Something added. grease or sawdust. if it has/had/could of/would of had gear oil there would be near nothing in the housing as it would have burned up.

new customer, i check all fluids, not only for level, but condition as well. After that i watch for leaks and check every other oil change.
Cant check mine though,some dumbass overtightened the plug. so next time cover comes off i will be surgically removing it.