2004 diesel 4x4 torque steer problem, we need help

[Deoprat]

I have a 2004 F250 SD diesel (6.0) automatic 5 speed FX4 off road 4x4 crew cab short bed with 3.73 gears(locker).

Problem is: (While holding the steering wheel straight and moving at highway speeds) upon heavy acceleration the rear of the truck moves to the right drasticly enough that it will change lanes on its own (the truck will itself dart left).
When acceleration is removed the truck will then dart to the right.
The Ford dealership (where I purchased the truck) has to date been trying to fix the problem for 5 weeks now.
The following has been verified: Allignment is good, all steering components are to factory specs, front and rear axel mounting points are good, front and rear springs are new.
The dealership has called in a Ford factory field engineer which has been working on the problem personally for 3 weeks and is at a loss. The Ford factory field engineer has even replaced the clutch pack and differentials in front and rear axel with factory new parts. To date nothing that has been done to the truck has had any affect on the problem at all.

Whats causing the problem?

[~manuel~]

Originally Posted by Deoprat

I have a 2004 F250 SD diesel (6.0) automatic 5 speed FX4 off road 4x4 crew cab short bed with 3.73 gears(locker).

Problem is: (While holding the steering wheel straight and moving at highway speeds) upon heavy acceleration the rear of the truck moves to the right drasticly enough that it will change lanes on its own (the truck will itself dart left).
When acceleration is removed the truck will then dart to the right.
The Ford dealership (where I purchased the truck) has to date been trying to fix the problem for 5 weeks now.
The following has been verified: Allignment is good, all steering components are to factory specs, front and rear axel mounting points are good, front and rear springs are new.
The dealership has called in a Ford factory field engineer which has been working on the problem personally for 3 weeks and is at a loss. The Ford factory field engineer has even replaced the clutch pack and differentials in front and rear axel with factory new parts. To date nothing that has been done to the truck has had any affect on the problem at all.

Whats causing the problem?

tell them to give you a new one as this one sounds like a lemon.