if you jack up your front end so the tires are off the ground, put one hand on the top of the tire, one on the bottom, and try to wiggle the tire( there shoudlnt be any play, if there is, replace the balljoint). the balljoint controls how much play/movement the tire has in either of those directions, where as if you were to put one hand on each SIDE of the tire and wiggle it the other direction, thats where your tie rods come into play...hope this helps give you an idea as to what the balljoint does.

they are literally so simple to do once you've done em once, youll be laughin.
