If your vehicle is showing steering wheel feels loose or jerky when driving over uneven pavement, here are the most likely causes and the parts you'll need to fix each one.
Tie rods connect the steering rack to the wheels. When the ball-and-socket joints on the tie rods wear out, they develop excessive play, causing the steering wheel to feel loose and jerk left or right when hitting bumps (bump steer).
Rubber control arm bushings cushion the suspension and keep the wheels aligned. When they tear or degrade, the entire control arm can shift backward or forward under impact, momentarily changing the wheel alignment and jerking the steering wheel.
Ball joints act as the primary pivot points for your front wheels. Worn ball joints allow the wheel assembly to move independently of the steering linkage, creating a loose, wandering feeling over uneven roads.
Internal gear wear in the steering rack creates a 'dead zone' in the steering wheel. Alternatively, if the rubber bushings mounting the rack to the frame wear out, the entire rack can shift when driving over bumps, causing steering feedback.
A severely worn wheel bearing allows the entire wheel and hub assembly to wobble. This looseness transfers directly through the steering linkage to your steering wheel, often accompanied by a humming or roaring noise.
Worn struts fail to dampen impacts and keep the tire planted on the road. As the tire bounces excessively over uneven pavement, it momentarily loses traction, causing the steering to feel jerky and uncontrolled.
If the wheels were recently removed for service and the lug nuts were not properly torqued, the wheel will wobble on the hub. This causes severe steering wheel shake and looseness, and can lead to the wheel detaching.
The intermediate shaft connects the steering wheel to the steering rack using universal joints. If these joints wear out or bind, you will feel a distinct clunk or looseness directly in the steering wheel itself.