The massive tie rod ends thread into the tie-rod end body so that they can be replaced without replacing the whole rod end, saving cost. The same threaded tie-rod end is used at all four points so only one spare has to be carried. The ends can be unscrewed from the rod end bodies and screwed in from the other side if a flipped tie rod and/or drag link is desired. The wrench is sold separately. We recommend purchasing it. Flipping the tie rod or drag link requires retapering holes from the top side of the knuckle.