[Carbeaux]

Your parking brake shoes should NOT be wearing out. They're only "on" when the truck is stationary. Make sure they're clean and adjust the star wheel, but make sure you loosen the nut by the pedal first. You should be able to turn that wheel with a slotted screwdriver, but I don't remember which way. Have some brake cleaner on hand.

 

[Carbeaux]

Well, the rear diff fluid is pretty thick stuff. All it has to do is combine with a little brake dust or other dirt or dust and it's going to resemble grease. When my seals went, that stuff was all over inside the wheel and wheel well. It was so thick that even when I had my tires rotated and the rears went to the front it slung more of that greasy stuff off and I had it in the front wheel well.

Clean the wheel on the inside and revisit it in a week or so to see if it's still clean.