_________ occurs when the lower control arm and steering tie rod travel along different trajectories.

• A. Camber change
• B. Toe out
• C. Ackermann effect
• D. Bump Steer

Answer: (D)

Bump steer occurs when the lower control arm and the steering tie rod don’t follow the same path as the suspension moves. As the wheel moves up and down, the control arm pivots and the tie rod steers the knuckle. If their trajectories aren’t aligned, the wheel’s toe angle changes unintentionally, even with no steering input. This is why you feel the steering pull or the car drift when hitting a bump or dip—the suspension geometry is causing toe to vary.

Camber change is about the wheel tilting inward or outward relative to the vertical as the suspension moves, not about the tie rod’s path. Toe out describes a static or directional toe angle, not the dynamic change caused by suspension travel. Ackermann effect refers to the ideal steering geometry that makes wheels point to the turn center, not to unintended toe changes during suspension articulation.