Shock Absorber Struts
Without shock absorber struts, you would be in for a very bumpy ride. Most people do not even realize what a difference shock absorber struts make in the performance of their vehicle. For those who are unsure what they are and how they work you may be interested in finding out more about shock absorber struts and how they are useful and a preferable part of your vehicle.
Shock absorber struts are used on all conventional suspension systems to dampen and control the motion of the vehicle's springs. Without shock absorber struts, the vehicle would continue to bounce after hitting bumps. The major purpose of any shock or strut is to control the ride and handling of the vehicle. Standard shock absorber struts do not support the weight of a vehicle. The springs support the weight and the shock absorber struts control the actions and reactions of the springs.
Most shock absorber struts are connected directly between the vehicle frame or body and axles. As the wheel rolls over a bump, the wheel moves toward the body and compresses the springs of the vehicle. As the spring compresses, it stores energy. The spring then releases this stored energy, causing the body of the vehicle to rise or rebound. After the energy in the spring is used up, the body starts downward and this causes the spring to compress. Without shock absorber struts, the energy released from the spring would be very rapid and violent. The shock absorber struts help dampen the rapid up and down movement of the vehicle springs by converting energy of movement into heat by forcing hydraulic fluid through small holes inside the shock absorber.
The hydraulic shock absorber struts operate by fluid being forced through a small opening. Besides small openings, pressure relief valves are built into most shock absorbers to control vehicle ride under all operating conditions. The greater the pressure drop of the fluid inside the shock and the greater the amount of fluid moved through the opening, the greater the amount of dampening. Therefore, larger shock absorbers can usually provide better dampening than smaller units.
Most shock absorbers on new vehicles are gas charged. Pressurizing the oil inside the shock absorber struts help smooth the ride over rough roads. This pressure helps prevent air pockets through the small passages in the shock. After the oil is forced through small passages, the pressure drops and the oil expands. Once the oil expands, bubbles are created. The oil becomes foamy and this air-filled oil does not effectively provide dampening. The result of all of this aeration is lack of dampening and a harsh ride.
The use of higher-pressure radial tires and lighter vehicle weight has created the need for more effective shock absorber struts. To meet this need, shock absorber design engineers use a pressurized gas that does not react with any other substances. The gas most often used for this is nitrogen, which is about 78% of our atmosphere. Typical gas-charged shocks are pressurized with 130 to 150 psi to help in both the handling and ride control.
Air-inflatable shock struts are used in the rear of vehicles to provide proper vehicle ride height while carrying heavy loads. It is also important not to exceed the load capacity of the vehicle or serious damage can occur to the springs, axles, bearing, and shock support mounts.
Now that we know how these work and why they are useful, it is important to keep up with your vehicle's maintenance. If you feel like you are not getting the smooth ride that you used to get from your vehicle, then you may want to have your shock absorber struts checked out by a mechanic.