I had an '05 6.0 with the torque shift that had a similar problem. I would put it in drive and it would roll backwards and just rev up then bang into gear! It would sometimes slip while pulling too. Ford had it 5 months before they finally decided to put a new tranny in it. The problem I had was that every time I drove it around the block and it did its same old thing and I brought it back, they would write it up as a slightly diff. prob., therefor I could not invoke the lemon law. Finally took it to a diff. dealer and got a new tranny, and never had another issue. Like Richard I pull huge loads sometimes grossing over 40,000lbs (that is 26,000lbs on my trailer) and don't have any trouble with these trannys! Keep on Ford, and make sure that if you have to bring it back they write it up as the same prob. just in case you need to invoke the lemon law, just my experience. Good luck!