Bucking F350

[jxc700]

I'm hoping somebody can help me! For the past 4 months I've had a problem with my 2004 F350, 6 spd man. bucking badly when under a load going up a hill. I've gone to 2 Ford dealers for help but they cannot figure it out. When I bought this truck it was an excellent truck so when it started acting up, I was told it was the clutch, so I had it replaced by the Ford dealer. The problem got worse. It's to the point now that it's not useable. The first dealer contacted Ford engineers who told them that I had to learn how to shift the truck. If I shift any sooner, the engine would be screaming. I brought it to another dealer who took it for a test drive and said there was definitely something wrong. They have changed the turbo, air filter, fuel pump, EBP sensor, IPR selenoid, PCM, ICP, FICM, MAF, BP sensor, EGR Valve, and nothing changed the symptoms. The dealer again called Ford Hotline and were told to stop working on the truck because it was a characteristic of the truck. As it is now, the truck is worthless to me. I don't know where to go next. Can you help me pleeeeeeeeease?

[big stroker]

Is it a 6.0 ?

[Deez7.3]

I had a 2000 F350 diesel and it would buck when i left a light or whats driving certain speeds. i would notice the bed bouncing up and down a little bit. I got rid of it before i fixed it but my friend and I came to the conclusion that it was the rear end. when the gears in the rear are under a load it can cause a sticking and slipping problem that could cause the bucking.