Which component connects the steering knuckle to the vehicle body in the suspension system?

The control arm is the component that connects the steering knuckle to the vehicle body in the suspension system. It plays a crucial role in maintaining the geometry of the suspension while allowing for movement of the wheel. The control arm pivots at the frame (or vehicle body) and connects with the steering knuckle, which is part of the wheel assembly. This connection enables the wheel to respond appropriately to steering inputs and provides stability during driving.

The shock absorber's primary function is to dampen the oscillations of the suspension system, improving ride quality and control, but it does not directly connect the steering knuckle to the vehicle body. The sway bar is designed to reduce body roll during cornering by linking the left and right suspension components but does not serve to connect the steering knuckle to the body. The spring is responsible for supporting the vehicle's weight and absorbing impacts from the road, but like the shock absorber and sway bar, it does not fulfill the role of connecting the steering knuckle to the vehicle body.

Thus, the control arm is essential for securely linking the wheel assembly to the vehicle structure, ensuring effective handling and suspension performance.