Adjustable control arms are necessary when you need to adjust caster of a front axle or the pinion angle of a front or rear axle, but if they are built like our JKS arms, they also can be used to add a little more wheelbase. We wanted to try to push the front axle of our TJ forward a little. The first step was to have a look under the Jeep to see if there was space for the front axle to come forward. Usually the steering is the limiting factor. On a front axle, you don’t want your tie rod hitting your pitman arm on suspension compression, or your sway bar hitting the springs. On a rear axle, you don’t want the diff cover hitting the fuel tank or tank skidplate. The best way to check this is by pulling the springs and putting the axle at full bump or where it has both bumpstops compressed.