When moving steering wheel on commercial truck back and forth this turned component should be?

When moving the steering wheel back and forth in a commercial truck, the component that should be turning is the steering gearbox or rack and pinion system. This mechanism translates the rotational motion of the steering wheel into lateral movement, allowing the vehicle's wheels to turn. Proper functioning of this component is crucial for steering responsiveness and safety. If there's excessive play or difficulty in steering, it may indicate a problem with the gearbox or related steering components.