when a dif goes you feel it trying to catch. they not wear out as much as explode when the pin falls out, you hear a chipping sound first then the pin comes out far enough to blow the case up.
the tc could have blow up too, when mine went it would drag the idle down low, and make it pretty hard to start up. would go into gears but was more locked up vs free revving.
a busted input shaft makes it 100% in operable.
at 300k how did the fluid look? still red? if its all dark and burnt up its rebuild time for sure, thats a load of miles.
