Automotive How To: Changing Your Shock Absorbers

The first sign is at night and you notice something is wrong. Bumps hit harder, the car rocks when you stop at lights and your headlights illuminate things they never did before. The obvious diagnosis, your shock absorbers are worn out.

What we incorrectly call shocks in the United States, the rest of the world refers to as dampers. A properly operating shock system pads those bumps, turns and dips from being extremely obvious. A car with a bad shock system will hit the bottom or top of its limits of travel when it encounters one of these obstacles.

Inside your shock a piston forces oil through orifices and valves as the wheel moves up into the wheel well. When you hit the top of a bump, a different set of valves allows the oil to return, resisting the return force. As the miles pile on, the piston and its sealing rings wear down, allowing more fluid to pass. Also the springs, washers, and other parts of the piston wear out leaving your vehicle to take those bumps and dips at full force. When your vehicle starts responding in such a way, its time to replace your shocks. You should always replace both shocks at once or your car will have a different response on each side of the car.

Traditional shocks used two concentric tubes but no single-tube shocks are becoming more popular. The new type uses gas under inert pressure to prevent aeration of the fluid. Although slightly more expensive, the one cylinder model offers a better ride. Replacing the shock absorbers is a straightforward, albeit difficult, remove and replace procedure and all it takes is simple hand tools and elbow grease. If you car has coil-over struts you should take it to a professional to be fixed as any mistake can be dangerous.