One thing I found with my truck not to long ago was the pitman arm was worn-replaced it, and the steering gear needed to be adjusted....helped a good bit...this could help you. One thing to see is get someone in the seat moving the steering wheel back and forth while you look under the front for any joints with slack in it...doesn't take much slack to make a big difference. To check the steering box, see whether the pitman arm moves "tight" with the steering wheel, or if when changing directions, there is slack there...do all this with the motor off. Hope it helps