Sounds just like the story of my '05, they would tear it apart and not find anything wrong and put it back together and I would drive it around the block and it would do the same thing it always did! They never figured it out, finally took it to another dealer who was able to pursuade Ford to just give me a new tranny. The last service advisor suspected there was a crack in something that only opened up when it warmed up and the pressure could'nt build right. I have know idea if he was right, I only know it took 5 months of fighting with Ford over the phone with no success before I got a new tranny. If I were you I would really try to convince them into just putting a new tranny in it now and not wasting your time driving a F150 when you are making payments on an '08 powerstroke! I had an '04 with a torque shift that did'nt down shift right and my dealership at that time did'nt hesitate to just put a new one in, no questions asked or time wasted!! I think a lot of it is up to the dealership, I know I would push hard for a new tranny! I hope you don't have to wait 5 months like me. Good luck!
