can anyone help, i have a 91 f-150, tire are 30x9.5or15lt, steering is horrible, if you hit a bump you fly into the other lane, how can i fix this????

 

Check your tie rod ends and the center linkages under your truck for wear. Also check the steering gear box for play or excessive wear, this is done by turning the steering wheel left and right and checking where it engages left and right. There should be about 1/8 of a rotation when it engages left to right. Another check is the front wheel bearing, check for play, Repack the front wheel bearing with wheel bearing grease aproved for disc brakes, and adjust wheel bearing nut. Make sure you replace the wheel bearing seal. Also check the steering gear box, it might be loose where it mounts to the frame, and aso check the linkage that mounts to the steering gear box for wear. Also check the ball joints.