hey i have a 1998 f-250ld 4x4 5.4L and the rebuilt tranny makes a humming or kindof buzzing noise on and off, i was wondering what would cause that? is it possible to have 200000+ on a transfer case and have it not need anything? what causes my rear diff pin to come out on my truck? any help is appreciated.

 

Are you sure it's the tranny? Not a heat shield on a cat?