Tie rods, ball joints, track bar bushings, control arm bushings. So much could be the problem. I am dealing with now myself. The slightest play can cause it. If you have a lift your track bar and drag link need to be plane. Either a drop on the track bar and/or drop pitman arm will fix that. You want it as close to stock as you can get. Unbalanced tires and alignment can contribute to this as well. Start with one component at a time and go down the list.