1994 s10 blazer 4wd problem

i have a 1994 s10 blazer that i accidentally drove in 4wd for an extended period of time (what i think i did was when i used the rear window wiper i hit the button by accident) now it has a vibration going down the road and will not shift into 4wd now is it possible that i destroyed the transfer case when i did it and do they make rebuild kits for them. thanks