A shock absorber on your car or truck is a hydraulic system that slows the motion of the springs when turning or cornering. If you didn’t have the shock on each wheel, the car would shake a lot more and yaw on cornering or tighter curves on the highway. What shocks do is steady the car on turns, keeping the center of gravity and the car from swaying, and also reducing the impact of small ruts and abrasions on the road surface. It’s also a safety issue, if you don’t have good shocks, the vehicle could sway when cornering to the point of causing you to go off the road.
Note: Most drivers don’t realize that over time, the gas charge or oil contained in the shock deteriorates and eventually reaches the stage where the shock is no longer viable.
Unfortunately, most people do not know that their shocks are bad unless they experience extreme tire wear such as cupping. Some tire shops may identify feathering or heel-toe wear as cupping. A wheel that is out of balance may also cause cupping or bald spots to form. The cause is mainly underinflated tires.
Note: If the tire has a lot of hills and valleys, you probably have a failed shock absorber, not necessarily just the bad tires. In short, you can’t keep tires on the car, because of the worn shocks.
One of the important things about having good shocks is in an emergency. If something happens on the road and you have to swerve, when the car catches up with the wheels, it tends to tip in the opposite direction of the way the car is turning. Again, good shocks will change the center of gravity and help you to keep control of your vehicle. The taller the vehicle, such as an SUV or truck, the more important it is to have good shocks and struts for safety.