A Watts Link is a four-bar lateral constraint linkage that locates a solid rear axle laterally relative to the chassis using two horizontal links connected to a central pivot bellcrank. Unlike a Panhard bar, which produces an arc-shaped lateral movement as the suspension cycles, a properly engineered Watts Link constrains the axle to move in a true vertical line, eliminating lateral roll-induced steer effects. Griggs Racing manufactures Watts Link systems engineered specifically for Mustang solid rear axle platforms.