Which of the following is NOT a part of the steering system?

The steering system of a vehicle is responsible for guiding the direction the vehicle travels by allowing the driver to control the wheels. The essential components of the steering system include the steering wheel, which is the primary interface for the driver; the tie rod, which connects the steering gear to the steering knuckles and helps to pivot the wheels; and the power steering cylinder, which assists in reducing the effort needed to steer the vehicle by using hydraulic or electric power.

In this context, a leaf spring does not belong to the steering system. Instead, it is a part of the suspension system, which supports the vehicle's weight and helps absorb shocks from the road. This distinction is crucial as it highlights that while the steering system directs the vehicle, the suspension system supports it and maintains proper ground contact for handling and stability. Understanding these components helps in identifying the functions they serve within the vehicle's overall operation.