Newby here to the F250 4WD truck world. I bought a 2004 F250 King Ranch that I knew had a few problems. First of all the thing, Hoss...yea I name everything, didn't drive well and had 315 mud tires on it which went away shortly. I noticed that I had negative camber, checked it out and I replaced all of the ball joints. The toe in went back to specs and all tie rod end and pitman arm joints are all tight. Even after all this, the truck does not want to recenter and it, I believe, is scared of big trucks and busses. Reason is...when I tooling down the road with my travel trailer, only 65-70, and a semi passes me it always becomes a white knuckle issue. The air pressure wave from the truck will push my travel trailer to the right and if I'm not right on top of it, Hoss will turn into the semis lane. If you over correct then you start wagging your tail and your pucker factor exceeds your limits and you'll need assistance getting free from the driver's seat. The previous owner added two springs to the front leaves and it raised it up in the front about 2" but I'm having trouble believing that this is causing my problem. I'm about to add caster wedges to the front and see if this helps with my straight ahead steering. Even a small amount of cross wind will make you knuckle down and gasp for breath at times. I'm starting to believe that my rear spring shackle bolts are loose along with the bushings but I don't see any evidence of it without tearing it down. Any ideas?