2001 Ford F350 7.3 liter diesel. Same problem as ive been hearing from others. Ive taken to Ford Mechanic and my own mechanic. Cant turn wheel when sitting still even when idling up. Every thing is new on stearing. Gear box. Pump, ball joints, u - joints, hub work. They said posibly hydro boost is bad or has presure restriction in maybe a hose that is deteriorating. And restricting? Help ive spent wayto much money on repair allready!