Place another one of the unused crossbar halves into the other side and thread them together until tight. A vise makes the job easier because the bushings make it difficult to get the crossbar half started on the set screw. Once the crossbar half is started, an adjustable wrench can be used to seat the two halves together. While still in the vice, use one or two adjustable wrenches to evenly clock the two halves together and place them perpendicular to the length of the shock. Once set, don't tighten them more than a half turn.