The suspension system of the car has three functions:

1. To allow the driver to have smooth control of the car,

2. To increase the comfort of the ride, and

3. To protect the mechanical parts of the car from the shocks of the road.

The suspension system in older cars used to just consist of metal springs (rather like very strong bed springs). Later shock absorbers ("shocks" were developed consisting of a valve that contains oil or gas.

As the car hits a bump or hole the springs absorb the shock of the motion. The "shocks" then actually absorb the motion of the springs, shortening the duration of the bouncing motion of the springs. The shock valves move down fast when a rough part of the road is encountered. The oil or gas then absorbs the shock and releases the valve slowly back to its normal position. This gives the passengers the sensation of a smooth ride. Essentially you are riding on a cushion of oil or gas. If you have ever dived into a swimming pool you know that the water breaks your fall, it absorbs the force with which you enter the water. The fluids or gases in the "shocks" work the same way.

These days the suspension system is designed to give independent suspension to all four wheels, greatly enhancing the car's ability to absorb the various shocks encountered. The shock absorbers are also very important in protecting the mechanical parts of the car from shock. Poor "shocks" are dangerous. If the "shocks" are gone you will have reduced control over the steering of the car especially at high speeds.

Test the "shocks" on your car. Push down hard on one side of the front of your car, over one of the wheels. Push up and down to get the car to bounce. Let go. Does the car bounce once and stop? It should. Repeat this with each corner of the car to test each shock. Does it bounce up and down several times? You need to get your "shocks" checked.