90 Suburban-transmisson/transfer Case

I HAVE A 90 CHEVY SUBN 3\4 TON 4X4,I WAS TRAVELING ALONG & STEPPED ON GAS A LITTLE TO PASS A SLOWER MOVING CAR & LOST ABILITY TO GO.THERE WAS NO WARNING,NO SOUND.I NOW HAVE NO FORWARD OR REVERSE.TRUCK STARTS & RUNS BUT ITS LIKE THE TRANSMISSON IS IN NEUTRAL.DOES ANYONE HAVE A CLUE AS TO WHAT MY PROBLEM COULD BE?THANKS :banghead:

Did you see if your linkage broke on the transmission? Do you have your fluid topped off?