Shock and Strut Inspection Shocks and struts are simple devices that dampen the movement of springs, suspension and vehicle pitch. For the most part, suspension works best with smooth weight transfers and the suspension is not compressed on the bump stops. As a vehicle brakes, accelerates, or corners, weight is transferred and the attitude changes. This can be helpful if done in an effective way. Weight transfer can also have momentum. If a driver makes a sudden lane change and a panic stop to the right, the weight will transfer to the left-front wheel. If that corner has a weak shock, the suspension could rapidly compress resulting in the vehicle going from an understeer condition to a “snap” oversteer condition which can roll the vehicle. The vehicle is better controlled with better shocks and struts.

Why Shocks Wear Shock SpringShocks wear because they work hard. On a smooth road, a shock strokes 1,750 times per mile. As a result, they wear out. Wear can occur between the piston and the tube allowing oil to pass through. Shocks are filled with oil that can have different weights. When the oil is cold it flows like 15-weight, but once it heats up it flows like a 20-weight. The oil can become contaminated with debris, so it is important to replace the dust boots when replacing a shock. If they bottom out, the piston hits the bottom of the valve, and can cause damage to the piston and valving. Mileage is a poor indicator of poor shocks. Constant inspection is really the only way to determine the condition of the shock or strut.