Truck Repair: 1999 chevy taho / 4wh.drive transmission, chevy taho, rear wheels

Question
MY FRIEND WAS BACKING HIS TAHO AND WHEN THE REAR WHEELS HIT THE GARAGE FLOOR HE ACCELERATED TO GET OVER THE HUMP, SOMETHING SNAPPED AND NOW HE HAS NO REVERSE. ANY IDEAS AS TO WHAT BROKE AND COST/PROCEDURE TO REPAIR THIS. THANKS DON

Answer
Hi Don,
I am not a transmission specialist, but it sounds like the anchor, or the end of the reverse band broke in the tranny.
I honestly don't know if a good transmission man can slip a band in while the tranny is in the vehicle or not. If not, a transmission dissassembly is required.
I would check the paperwork, and see if the drivetrain warranty might still be in effect.
Van