have you done anything to the tcase? check the shifting linkage, your's is probably different than mine but the way mine is, there's a stud and a nut that connects it and if that isn't hooked up it wont shift. my tcase runs on atf, most run on gear oil tho, maybe check fluid and flush fluid. ummmm... i've never had tcase problems other than accidently drowning it. check your drive line too, might not be the hubs that weren't working... hope that helps a little