The Suspension and Steering System

A vehicle's suspension and steering systems allow the driver to properly control the automobile on the road. The steering system allows the driver to control the direction of the vehicle's motion (See Figure), while the suspension system keeps the tires in contact with the road (even while the vehicle is traveling over rough road surfaces).

To permit easier driver control, virtually all steering systems produced today contain some type of power assist. The power assist helps the driver by making it easier to turn the steering wheel. This type of steering system is commonly called power steering, and it's standard on almost all vehicles. The power assist is usually provided by a hydraulic system. Hydraulic fluid is pressurized by a pump and then directed into the steering system to help turn the car's wheels.

An automobile's suspension system not only keeps the tires in contact with the road, but also provides a smooth ride for the passengers. When a vehicle travels over a rough road surface, the suspension system absorbs the bumps and prevents them from disturbing the vehicle's passengers (See Figure). Modern suspension systems are designed to provide a smooth ride at highway speeds as well as at lower speeds. Note that the smooth ride must be achieved while still keeping the vehicle in firm contact with the road so that it can be safely controlled by the driver.