Steering issues
 

A few months ago i started having problems with the trucks steering.....it happens when i make a sharp left or right turn and then after violently jerks to one side or the other. I parked the truck for a few weeks to gather more info and contacted (friend) diesel mechanic. I was informed that the steering gear box was the cause......i replaced it drove it for a few days and the story continues nothing has changed other than my bank account. I hear a whine constantly and i cannot turn wheel unless giving throttle at a stand still. I dont want to keeep throwing parts at it but i mean i gotta get fixed.....power steering pump????

Power steering pump, at least that's the whining noise. The violent jerking seems like a worn tierod or something of that nature.