The hydraulic dampening of the Oldsmobile shock absorber allows for a smoother ride the passengers of the vehicle enjoy. This dampening effect also reduces excessive vibration in other suspension components and the car's chassis. The Oldsmobile shock absorbers are in place to counter the effect of the vehicle's up and down movement that is created by the action of the coil spring when an obstruction is encountered on the road. On older or much larger Oldsmobile vehicles, there could be four shock absorbers. For those vehicles that are newer or smaller, there may only be two in the rear while Macpherson struts perform this duty in the front. The way a shock absorber is able to counter the movement of the spring is by utilizing its internal hydraulic system. This includes the movement of its piston as it compresses the hydraulic fluid or gas in its cylinder. This compression dampens the up and down action brings the body of the vehicle back to a steady position. As the shocks wear over time this dampening effect is reduced and replacement becomes a necessity. If the shock absorbers are suspected of not performing their duties, a simple bounce test can be conducted to determine if they are worn and in need of replacement on your Oldsmobile. This is accomplished by depressing a corner of the vehicle and releasing it. The movement of the body has to then be observed. If the body of the Oldsmobile moves up then back to a resting position once, then it is still functional and no replacement is necessary. If the body moves up and down two or more times, then replacement of the shock absorbers is required for the longevity of the other auto components to have this reduced level of vibration required for their continuing ability to function properly.