Chevrolet Repair: 1999 silverado Z71 4.8 litre engine, forward gears, trannys

Question
reverse does not work, all forward gears work but trans does labor some between 1st and 2nd before it shifts.problem started after my son pulled a friend outta ditch, he used 4 wheel drive in reverse

Answer
Not saying the trucks aren't good but the trannys really can't handle much. It's been my experience that they just can't handle the pressure, I have spewed more trannys after using Fwd than I have in anything thing else. I would have to say the tranny is fried.