I finally got around to changing the transfer case and front differential fluids in my truck. The transfer case fluid came out looking decent, but the front differential was absolutely awful looking. There was a good amount of gunk/ metal shavings stuck to the drain plug that has the magnet on it. I really wish I would have changed it sooner, back when I did the transmission and rear differential at 46k miles as the truck has 85k on it now. I don't recall the rear differential fluid looking so bad when I did it. And the 4 wheel drive doesn't get used all that much, although it does run in 4 Auto a lot in the winter, so....I changed them out with AMSOIL products. So, if you haven't done your fluids yet, I would really recommend doing it.