If a mechanic pushes out and then pulls in on both tires of a jacked-up car and notices too much movement, what does that indicate?

The observation of too much movement when pushing out and pulling in on both tires of a jacked-up car indicates that the tie rod ends are worn. The tie rod ends are critical components of the steering system, connecting the steering rack to the steering knuckle. When these components are worn or damaged, they lose their ability to hold the tire in the correct position relative to the steering mechanism, resulting in excessive play or movement.

Under normal conditions, the tie rod ends should provide a stable connection that prevents any noticeable lateral movement when force is applied to the tires. If the joints are worn, they will not resist movement effectively, which can lead to issues such as poor steering response and uneven tire wear.

While other components like ball joints, wheel bearings, and strut mounts also play significant roles in the suspension and steering systems, they each affect vehicle handling differently. The specific action of pushing and pulling the tires primarily tests the tie rod ends for play.