When the steering wheel is turned, through what component is the movement transmitted?

The movement of the steering wheel is transmitted through the pitman arm. When the driver turns the steering wheel, it engages the steering column, which is connected to the pitman arm. The pitman arm is part of the steering gear assembly and acts as a link between the steering gear and the rest of the steering linkage.

The pitman arm converts the rotational motion from the steering wheel into the linear motion needed to turn the wheels of the vehicle. Thus, it is crucial for steering precision and responsiveness. This makes it a vital component in the overall steering system, facilitating the transfer of driver input to wheel movement.

The other components listed play different roles in the suspension and steering system. While the idler arm supports the steering linkage and maintains proper alignment, it does not transmit the steering wheel's movement directly. The control arm is part of the suspension system that connects the vehicle frame to the wheel assembly, allowing for vertical movement of the wheels. The trailing arm similarly serves to connect the rear axle to the vehicle body but is also not involved in the steering mechanism.