When I hit a bump, my car suddenly jerks to one side. Is anything wrong?

Yes. The condition is called "bump steer," and it means your steering linkage is not mounted parallel in the chassis possibly as a result of collision or frame damage, a bent steering arm, misalignment in the chassis, or an improperly mounted steering rack.

Bump steer is not a very common condition, but it can be a very unnerving thing to experience if you're unfortunate enough to encounter it. It is usually most noticeable when crossing a major dip or bump at speed, as when crossing a railroad crossing or passing through an intersection with a lot of road crown. As the suspension bounces over the bump, it suddenly feels as if someone tugged on the steering wheel. The car twitches or jerks to one side as if it has a mind of its own. This occurs because of unequal toe changes that occur as the suspension extends and compresses.

In a properly aligned car, the toe alignment of both front wheels changes equally as the suspension moves up and down. But if something causes more of a toe change in one wheel than the other, it will jerk the steering towards the side with the greatest toe change.

The thing that needs to be checked is the parallelism of the steering rack and linkage with respect to the ground. This can be done by simply measuring the distance between both ends of the rack and the ground. If one end of the rack is sitting higher than the other, the rack is misaligned in the chassis. If it can't be corrected by loosening and retightening the rack mounts, the subframe or crossmember on which the rack is mounted may be bent or damaged. This will require special straightening equipment or replacement to correct.

The height of the outer ends of the tie rods with respect to the ground should also be measured. If one tie rod is higher than the other, one of the steering arms is probably bent. The cure here is to replace the steering knuckle.

CAUTION: Bending a steering arm to "correct" a bump steer condition is not recommended because doing so may weaken the arm and increase the danger of it breaking.