A ball joint is used to connect a steering knuckle or spindle to a control arm. Thanks to its special design it allows for moving in all directions, which makes it possible to turn the front wheel when necessary.
By design, a ball joint is a metal sphere with a threaded tapered stud inside the housing. The latter is filled with grease to ensure proper ball joint lubrication and to prevent it from overheating and excessive wear. To keep the grease inside a ball joint and to protect it from dirt, moisture and debris, the ball joint is shield with a rubber or polyurethane boot.
Depending on your vehicle, you may have two or more ball joints. Most automotive suspension systems feature one lower ball joint per drive wheel, however, there are vehicles with front upper ball joints and/or rear ball joints. Regardless of their quantity in your vehicle, they are crucial for both steering and suspension systems because they are what connects your wheels to these systems.
In an ideal world, your ball joints would live the lifetime of the vehicle. But, in reality, they are exposed to heavy loads, helping your vehicle to tackle bumps, potholes and other road imperfections. For this reason, they are prone to wear and tear, which is why they may fail suddenly. If this happens, bad ball joints must be replaced as soon as possible to avoid drivability issues.
Ball joints are essential components of your steering and suspension systems, which is why their failure will affect your vehicle driving control and stability. In the worst-case scenario, this can lead to an accident, so it’s better to prevent that unwanted turn of events. To help you out with that, we recommend you to check the warning signs of a bad ball joint:
Your ball joints must be properly lubricated to ensure smooth and quiet operation. For this reason, they are lubricated with special grease. The grease is held inside the ball joint housing with the help of a rubber boot. If the latter gets damaged, the grease may escape from the boot, causing a lack of lubrication. As a result, you may notice a squeaking noise when cornering or driving over bumps.
A worn-out ball joint can allow for abnormal movements inside the socket when your suspension and wheels are going up and down, trying to tackle bumps, uneven terrains and other road imperfections. If so, you will notice clunking or knocking noises which will become louder until the ball joint breaks down.
Abnormal vibrations and some erratic wheel movements can be caused by a loose or worn-out ball joint. It may lead to wandering steering and excessive vibrations you may feel through the steering wheel.
Under normal conditions, your front wheels are properly aligned to keep your vehicle moving straightforward. However, a loose or worn-out ball joint can cause your vehicle to pull to the left or right. To keep your vehicle moving forward without rolling, you’ll have to compensate for the erratic movements with the steering wheel.
Ball joint troubleshooting and replacement
While some older ball joints can be lubricated, most modern ball joints aren’t serviceable. They must be replaced with brand-new items if there is excessive play or their rubber boots are damaged.
As a rule, automakers do not provide any time or mileage intervals for their ball joints. However, we recommend you to inspect your ball joints for damage and wear each time you work on your suspension system or change engine oil.
Depending on your driving conditions and average mileage per year, your ball joints can last up to 30000 miles and even longer. Although, sooner or later you’ll need to replace your ball joints to ensure a safe and smooth ride.
Wandering steering, uneven tire wear and other steering problems can be indicators of bad ball joints. Once you notice any of the warning signs, you should get in touch with your mechanic to have your suspension and steering systems inspected. The mechanic will check the ball joints for excessive pay and we’ll recommend you to replace them if they are damaged or worn-out. In most cases, it is recommended to replace both left and right ball joints at the same time even if the only one is faulty. This will prevent possible failures in the nearest futures since the other ball joint can also be at the end of its service life.
The repair cost may vary depending on the vehicle. Some models feature replaceable ball joints, while others come equipped with control arm and ball joint assemblies, which must be replaced together. This will increase the cost of the replacement part and involve additional labor. Besides, if you also have rear ball joints, the final cost can be even higher.
Your ball joints belong to both steering and suspension systems, which is why replacing bad ball joints should be left to a professional. He or she will inspect the suspension and steering systems for wear and damage and will provide you with the estimate. In most cases, raising up the vehicle will be required to access faulty ball joints or other failed components. Some special equipment and safety tools such as jack stands and protective goggles may also be necessary to do the job.