Car Suspension Basic Anatomy Lesson

You may not even notice your car suspension and everything it does for you. Because there are many dynamic forces at play and the road is certainly never smooth, your suspension system has to work hard to keep your wheels firmly planted on the pavement and help you maintain control of your vehicle. In fact, the only time you may notice your suspension is if it isn’t working properly.

Car Suspension: Taming Forces

As you drive around, your vehicle experiences forces, for example, when you accelerate, all the weight in the car tends to roll backward, while braking tends to force everything forward. Without the suspension, all that movement would quickly become uncomfortable, not to mention that traction could be reduced.

While you’re turning, weight tends to shift toward the outside of the turn, so the tires on the inside of the turn would lose a measure of traction and control. Finally, irregularities and bumps in the road would easily make driving quite uncomfortable and reduce traction and control if the tires lose contact with the road. Every part of the suspension system is designed to help you maintain traction, control and comfort in your vehicle.

Car Suspension System Parts

Here are a few parts of the car suspension system in most vehicles and their functions. Note that these parts interact with each other, and some parts may play multiple roles:

• Control Arm

Depending on the suspension system in question, such as wishbone or multilink, control arms define each wheel’s range of motion. In the rear, this is limited to a more-or-less up-and-down motion, while the front also allows for turning left and right.

• Ball Joint

In the front, the wheels need to turn left and right to allow for turns. The ball joint allows not only for turning but also the up-and-down motion of the control arms.

• Spring

Between the control arm and the frame or body, leaf springs, coil springs or torsion bars support the weight of the vehicle. Some coil springs may be part of the damping system, such as MacPherson struts or coil-over shocks.

• Shock Absorber

Normally, a spring in motion will continue in motion, so a vehicle that hits a bump will simply keep bouncing unless there is something to stop it. Using hydraulic fluid, the shock absorber or damper slows and stops these oscillations.

• Anti-Roll Bar

Sometimes called a sway bar, this part of the car suspension is connected between the control arms on the left and right and to the body in the middle. It helps to control body roll in turns, improving traction and control.

If something goes wrong, then you can usually tell what part of the suspension is faulty by the symptoms you experience. For example, if your car is too bouncy, maybe the shock absorbers are worn. If your car seems to roll too much, maybe you have a problem with the anti-roll bar or its links. If your tires are wearing unevenly, perhaps you have a loose ball joint or need a suspension alignment.

Check out all the steering and suspension parts available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on taking care of your car suspension, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Photo courtesy of Wikimedia Commons.