In a Mopar front suspension, the lower control arms are like heavy equipment on a job site. They transfer all the torsion bar's force and actually hold the car up, while the strut rods handle the fore and aft forces. The upper control arms locate the uprights and swing along for the ride. When Mopars are equipped with a sway bar-you guessed it-they tie into the lower control arms. If performance handling is the goal, the lower control arms had better be in top condition.
What can go wrong with such a simple looking chunk of metal? There's no question the first thing to blow out of a Mopar front suspension is also the toughest part to replace: the lower control-arm bushing. When the bushings go, accurate control and handling go with it. The lower control-arm bushing is the only replaceable "wear" part on the arm, but it is also the most critical bushing in the suspension. We've got some tricks to make the nasty job of replacing it easier.
We're in the process of building a hot-handling E-Body, which will see a host of suspension and braking upgrades up front. When we heard our pals at AR Engineering had fabbed-up reinforcements to beef up the lower control arms, it made perfect sense to investigate it further. The AR piece boxes the open lower section of the arms, and the prospect of added strength to these highly-stressed units got our attention. After all, looking at the stock control arms, it is clear by the beefy vertical section that they are built to take an enormous amount of loading in a vertical plane-no surprise, since the major loading is vertical, supporting the vehicle's weight. Now think about a fat sway bar linked in front of the arms' centerline. What we now have, in engineering terms, is a torsional moment; the sway bar forces want to twist and distort the control arm. Our plans included a fat aftermarket front sway bar, and any extra muscle we could add to the arms would be welcome.