Caked dust - a telltale sign of a slow leak.
TL;DR - the form in place gasket (FIPG) used to seal the carrier to the rear axle housing is leaking just a tad and needs replacing.
Not much more to say about this for now. I suspect this will be a reasonably straightforward fix, which I'll take care of when I change the oil in the rear diff this winter. The biggest issue will be cleaning the mating surfaces well in order to get a good seal.
In this Series
The Rear Diff is Weeping (new)Dec 18, 2022
