Suspension Shock or Strut Replacement
What is a Suspension Shock or Strut?
Most passenger cars, trucks, and SUVs today feature an integrated steering and suspension system. At the heart of the suspension is the strut assembly, a mechanism that combines a shock absorber and a coil spring into one unit to absorb bumps in the road and to keep the tires in contact with the ground at all times. The top of the strut is also used as the upper pivot point of the steering system. While this is most common, many vehicles past and present still use a shock absorber instead of an integrated shock and strut. These work in exactly the same way, except they are independent of the coil spring.
How do Suspension Shock or Struts work?
There are many components that make up the steering and suspension systems on a vehicle. The wheel is bolted to a wheel hub that turns inside bearings set in the steering knuckle. The knuckle, in turn, is connected at the bottom to a moving bracket called the lower control arm, and at the top to the strut and possibly an upper control arm. The steering gear is attached to the knuckle by way of the tie rods so that when the steering wheel is turned, the knuckle turns with it, rotating on the lower control arm and the upper strut mount. The strut assembly, widely known as a MacPherson strut, is made up of a special shock absorber, a coil spring, and the rotating upper strut mount and bearing assembly. Additionally, vehicles using shock absorbers instead of struts will have the shock mounted to the chassis and the lower control arm. This allows the shock absorber to moderate the movement of the coil spring, preventing the vehicle from bouncing up and down indefinitely.
What are the symptoms of a bad Suspension Shock or Strut?
Because the suspension struts and shocks control the entire weight of the vehicle, they can wear out over time. The shock absorber is usually the first to go. When this happens, the ride quality becomes "bouncy" or loose, and the vehicle's ability when cornering in a turn diminishes. Oil may be seen leaking from some types of struts and shock absorbers. Also, since the upper mount is constantly being turned or compressed, it will eventually break down and squeak of clunk over bumps and during turns. For struts, a clicking or growling noise when turning can indicate a worn bearing inside the upper strut mount, and a squeaking sound when the steering wheel is turned can mean that the rubber bushings in the mount are decaying as mentioned. Also for struts, the coil spring can break and cause a loud clunking sound when turning or when going over bumps.