I have a 2003 Hummer H2 with about 106k mile on it.

So first what happen was, while driving the truck it will not shift from 2nd to 3rd or 4th gear it will only rev when accelerator is pressed and this continued for some days and when the last time I drove, while driving all of a sudden there was no acceleration as if the transmission went in to neutral and i could hear some grinding/cranking kinda noise.

I switched to reverse from drive, vice-versa and but none of the gears are engaging and the truck will not move.

Any ideas what could be the problem, like transmission needs to be rebuild or transfer case is faulty?

Thanks.

 

"i could hear some grinding/cranking kinda noise" Drop the transmission pan and inspect!

 

I know this is really obvious, but you sure that:

1. You used only GM Dexron VI trany fluid?
2. That your transmission fluid is full?

I have seen your type of problem when # 1 or #2 were not followed.

But your problem may be more sinister.....