Truck Repair: wheel hop on my 9900i

Question
I have nasty wheel hop @ about 45-50mph,i have changed tires,checked u joints,hangar bearing,changed shocks.have little play in output shaft,had 2 shops say play is acceptable.Wheel hop is worse with trailer on. when loaded wheel hop is more like chatter going up hill.

Answer
If all that checks out good I would check or just repace your air bag leveling valve. More then likely it's filling your bags up and not lowering them fast enough to keep up. Also might check what the height measurement is. Have to call a dealer to find out their recommended measurement.  I measure from the center weld of the rear axle to the bottom of the frame rail.