Suspension Basics

The suspension system of your vehicle consists of the parts that connect your vehicle to its wheels and allows for movement between the two. The suspension system regulated the bouncing motion your car would go throughout on the road, thus making your drive more manageable. It also protects your vehicle from damage and wear. No matter how you drive, your suspension will be affected. Driving on dirt or gravel, off-roading, and braking hard all use your suspension. A good suspension system should be able to last through hours of forceful use in both daily and extreme circumstances. However, eventually, all suspension systems will wear down and even break in extreme circumstances. It is important to know about the parts of your suspension and also warning signs of when they need to be replaced.

Suspension Parts


Most cars have four springs that are made of steel or fiberglass and wound in a spiral shape. They hold the weight of the car and absorb the energy of a bump in the road. Springs are designed to last the lifetime of a vehicle and should rarely need replacing if they are sized properly. However, they can be damaged. If your car is on level ground but one corner is lower than the others, then that is a sign of a damaged spring. Also, if you hear clunking noises over bumps or your car doesn’t turn on corners well, then you may have a damaged spring.

Shock Absorbers

Also called “dampers,” shock absorbers work to minimalize the natural tendency your springs have to oscillate. They use oil and gasses to absorb excess energy from the springs. If your car only had springs, it would wobble, shudder and bump along the road. When they wear out, you’ll notice more bouncing after a bump and a lot of shaking over rough roads because they can’t keep the tires planted on the pavement. To test your shock absorbers, push down on one corner of your vehicle and count how many times it bounces. If it bounces more than twice, then your shocks are worn.


The strut combines the spring and shock absorbers into one unit. When struts are worn, there could be excessive vehicle-weight transfer from side to side and front to back. This reduced the ability of your tires to grip the road, thus affecting handling and braking performance.

Anti-sway/Roll Bars

When you turn your vehicle, there are forces that want to roll your car’s body to the outside of the turn. Anti-sway/roll bars work to counteract this and keep your wheels in contact with the ground. Anti-saw bars are metal rods that cross the entire axle and connect each side of the suspension together. When the suspension moves up and down at one wheel, the anti-sway bar will transfer movement to the other wheel reducing vehicle sway.

Control arms

Control arms are hinges that hold the wheels to the frame and connect the steering to the wheels. They have bushings which are rubber or metal parts that help absorb shock.  Your lower control arm bushings are more prone to wear out on front-wheel-drive cars than on rear-wheel-drive cars.When the bushings wear, they can cause ride and handling problems and accelerate tire wear. A bent control arm can also cause this problem. If you hear clunks or rattling, your wheels are moving back and forth in acceleration and braking, or you have loose, imprecise steering, then it is time to check your control arms.


The spindle connects the lower control arm and the upper control arm. It is the center point for your wheel and rotor to rotate around and should remain as parallel to the road as possible.

Ball joints

Ball joints connect your control arms to the spindle, helping your vehicle to move up and down with the road. They absorb some of the shock from up and down movement and rotate as the steering angle changes. Ball joints are usually lubricated with grease and then sealed and some have a grease fitting that allows for adding more grease. If you hear squeaking or creaking, especially when turning, then your ball joints need to be replaced. If your ball joint breaks, then your suspension parts will drag on the ground.

Suspension Maintenance

You should check your owner’s manual for a mileage estimate for your suspension parts. Depending on how you drive and your road conditions, your shocks and struts will need to be replaced between 60,000 and 75,000 miles. For general maintenance you should check your shocks or struts for leakage. You should also pay attention to how your car handles, noting if the ride is becoming more bouncy and uncomfortable. Have your mechanic check your ball joints at least twice a year or whenever your car is inspected. If your ball joints separate, you can lose control of your vehicle. Make sure you or your mechanic lubricates the ball joints and any other suspension components at each oil change.

If you suspect that there is a problem with your vehicle’s suspension system, schedule an appointment with the Auto Clinic of Stuart. We will help you get on the road safely and make sure your suspension system stays in good working condition.