Alright so I took my toyota on its first highway drive yesterday. It has power steering and 35s. Whenever the road would be slightly uneven it'd pull HARD to that side. Later last night at home I was playing with the steering wheel and it just starts moving back and forth about two inches each wiggle with the truck at a stand still and my hands off the wheel. Sure scared the hell out of people swerving all over a 50mph

 

How long have the 35's been on it and did you check your steering stabilizer?

 

Make sure there is no slack in the steering box, if there is, it is adjustable, but there is a proper way to adjust it without having issures (as you know steering issues on the road is the last thing you want), make sure you don't have loose in the steering column u-joint, steering box u-joint, tie-rod ends and as mentioned above steering stabiliser.

 

First check your drag link for play, then steering stabilizer and then the worm gear adjustment.

 

I had the same problem with my truck, turns out that the front shims where on backwards and the tie rod ends where bad. But the shims really screwed it up. The thick end needs to be facing towards the rear.