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Ball Joints – What and Where are They?

car balljointsYou may understand that the suspension system in your vehicle is responsible for controlling the comfort of your ride. While the suspension system is made of several components, one of the most important components is the Ball Joints.

What are ball joints on a car?

Ball joints are globular bearings that connect the control arms to the steering knuckles. Surprisingly, you could compare the design of ball joints to the hip joint on a human body, as they have a similar ball-and-socket design. The ball joints allow pivoting between the control arms and the steering knuckles that connects the wheel to the suspension system. The control arm connects the wheel hub and steering knuckles to the frame of the vehicle. The control arm permits the wheel to move in an upward, downward, and turning movement as well as prevent any movement in the opposite direction. The front suspension will often have an upper and lower ball joint on each side of the vehicle while the independent rear suspension will have at least one ball joint on each side.

Are There Different Kinds of Ball Joints?

Ball joints are designed to be load bearing or non-load bearing and are either sealed or non-sealed.

Load bearing ball joints take on the weight of the vehicle while providing a pivot point. On the contrary, non-load bearing provide a pivot point without supporting any load of the vehicle. Because of the additional weight they must shoulder, load bearing ball joints tend to wear faster than their counterparts.

Sealed ball joints are found on most modern-day vehicles and require little to no maintenance as they are protected from exterior elements and are designed to be lubricated indefinitely. However, they should be inspected with each oil change for signs of wear. Non-sealed ball joints are not as common as they once were and require occasional lubrication by the grease fittings, often referred to as “grease zerks.” They should be checked at every oil change. Maintaining non-sealed ball joints is a fairly simple process for a technician to perform. Once new grease is added to the fittings, the pressure going into the joint, forces the old, spent lubricant out.

What are Symptoms of Bad Ball Joints?

Depending on your driving habits, your vehicle’s ball joints can fail as soon as 80,000 miles. However, with rough driving, a modified suspension, or use of oversize tires and wheels, replacement may be required sooner. Many newer vehicles today have a wear indicator alerting the driver when the ball joints need replacement. You may also notice that that the car pulls to one side and requires constant correction by the driver to remain on the road. Other symptoms include:

    • A clicking, popping, or snapping sound when the wheel is turned.
    • Thud sound when going over bumps.
    • Uneven tire wear.
    • Alignment issues.

If the vehicle experiences any of the symptoms and is not equipped with a wear indicator, a certified technician will need to verify if the ball joints have already gone bad or are on the decline. For non-load bearing vehicles, the technician will test the vehicle by raising the vehicle into the air, grasp each tire at 9 and 3 o’clock and attempt to push and pull it. The wheel should not move, but if it does, this is a clear indicator that something is loose and new ball joints could be required. For load bearing vehicles, the technician will place a jack or jack stand underneath the loading joint and continue the same procedure as with a non-load bearing vehicle.

If your vehicle indicates that the ball joints are in distress, either by the indicator light, or by other symptoms, its strongly suggested you take your vehicle to a trusted mechanic. Without the ball joint restraining the wheel, the suspension will come apart, causing the vehicle to come to an abrupt stop and may permanently damage tires or worse—cause them to detach from the vehicle completely. It’s also important to note that after your ball joints have been replaced, an alignment should be performed to ensure the tires are set properly.