The Suspension system of your vehicle, serves several important functions. It supports the weight of the frame, body, engine, transmission, drive train and passengers. It keeps the vehicle from tilting down in front when braking and in rear while accelerating. The suspension also helps keeps front wheels pointed straight forward and provides for the steering motion from side to side. The other thing it does is provide a smooth, comfortable ride by allowing the wheels and tires to move up and down with minimum movement of the vehicle body.
Control arms, steering knuckle, ball joints, springs, shocks and struts are all part of this system and all have their own specific job to do, to keep you driving smoothly down the road.
Springs come in two types, Coil Springs, which are a length of spring-steel wound into a spiral and Leaf Springs, which is constructed of flat strips of spring steel that are bolted together. Springs support the weight of the vehicle, while still allowing the suspension room to move in response to the road. Coil springs are mostly found in passenger cars and light trucks and can be found in the front or the rear of the vehicle.
The Control Arm supports the steering knuckle and axle housing in position as the wheel moves up and down. The outer end of the Control Arm contains a ball joint and the inner end contains bushings. Rear control arms may have bushings on both ends. A strut rod fastens to the outer end of the lower control arm and to the frame. It keeps the control arm from swinging out of place.
Ball Joints create connections that allow for limited rotation in every direction and must be filled with grease to have smooth operations. If the boot that covers the joint is dry rotted or damaged, the grease inside will get dirty, dry up or wear off, causing damage to the joint and limiting your vehicle’s steering abilities.
Shock Absorbers (Shocks) limit the movement in the springs. When your shocks are worn, the vehicle will continue to bounce up and down long after hitting a dip or bump in the road. A shock can be filled with oil, gas/air, or sometimes both.
A Strut Assembly (Struts) consists of a shock absorber, a coil spring, and an upper damper unit. This strut often replaces the upper control arm.
A Sway Bar or Stabilizer Bar, is used to keep the body of your vehicle from leaning excessively during sharp turns. It is made of spring steel and fastens to both of the lower control arms and to the frame. Rubber bushings fit between the bar and the control arms and Sway Bar Links connect the sway bar to the control arms.
Decoding the suspension system requires experience, a test drive and placing the vehicle on a lift to thoroughly examine all of the individual parts that work together to provide your vehicle with a smooth and controlled driving experience. When dropping a vehicle off at our shop for suspected suspension trouble, please give as much information as possible, noises you hear, where they seem to be coming from, sensations in the ride experience and in the steering wheel are good places to start to help us figure out where your vehicle’s suspension needs attention.