Originally posted by y-knot
The spacer has nothing to do with the wheel jumping up and down. The motion (oscillation) is suppose to be controlled by the shocks. I have run a spacer for years now and they do not give you any problems. You most likely have two problems. First you raised the trucks height by 2", if you live in a very bumpy, rough area and the suspension is asked to travel to it's limits. Your shocks are most likely bottoming out, they were not designed to extend as far as your truck is asking them two, so when you hit bumps and the suspension moves, it is suddenly stopped from extending by the shock. The second thing you have, is most likely worn, bad, week shocks. Both problems can and will be solved by the replacement of your shocks with new, quality, longer then stock shocks. Tell the salesman that you have raised the trucks front height, they will then be able to get you the right ones. Also, I would replace the rears at the same time.