The control arm holds the wheel in place and absorbs braking, potholes, and acceleration. When its bushings or ball joint have play, the alignment moves under load: the steering becomes vague, the tire wears unevenly, and no wheel alignment setting holds.

A new control arm restores the car's original precision - it's a repair, not a performance upgrade, but it is often the most noticeable change you can feel on a ten-year-old car.