Why should shocks and struts always be replaced in pairs?
Unlike other parts of the steering and suspension system, shocks and struts on the left and the right sides of a vehicle wear at about the same rate. If one shock or strut has gone bad, the other is likely to go bad also. There is a difference in the wear rates between front and rear shocks and struts, but this depends on the loading of the vehicle. In general, if the front shocks or struts need replacing, so do the rear ones. Shocks and struts are designed to dampen spring oscillations as the suspension goes through bounce and rebound. This prevents unwanted gyrations and helps keep the wheels in contact with the road. The resistance inside the shocks or struts dampens spring oscillations while limiting body and suspension motions. After years of use the pistons and shaft seals inside the shocks or struts wear out. Shocks may need replacing in as little as 30,000 miles. Struts usually last about twice as long. The deterioration in ride quality due to wear on the shocks and struts is v
