Shocktober Suspension Basics: Control Arms and Bushings
Happy Shock-tober! We're using the entire month of October to review suspension basics, maintenance, and repair. This article was originally published in January 2018 and has been updated.
Control arms and bushings are critical components of your suspension system. Working together, they allow your tires to move up and down in a smooth, controlled motion. Without them, most rides would be extremely rough and uncomfortable.
Control Arms
Control arms connect the wheel hubs and steering knuckles to the frame of the vehicle. They allow the wheels to move up and down while preventing forward and backward movement. Most cars have one or two control arms per wheel, one upper and one lower, on both the front and wheel suspensions. Most trucks and SUVs have both an upper and lower control arm, while many front wheel drive vehicles only use a lower control arm.Bushings
Many suspensions and steering joints utilize bushings where vibration is concerned. they can be used in control arms, shock absorber mounts, stabilizer bars, stabilizer links, engine and transmission mounts, and other suspension and steering components. Bushings are especially important, as they impact comfort and handling. They cushion the suspension system, which controls noise and vibrations and provides a softer ride on rough roads. Their unique material can flex and move, but always return to the original shape and position.Some Common Problems
Bushings function similarly to cartilage. Worn or damaged cartilage results in bone-on-bone contact and discomfort. Similarly, worn or damaged bushings can allow metal on metal contact, tire wear, uncomfortable rides, noises, and vibrations. Bushings typically deteriorate due to heat, age, exposure, heavy loads, salt, oils, and the stress of frequent movement.