On automobiles, ball joints are the bearings that connect the control arms and steering knuckles. They’re spherical in shape and present on all makes and models. Along with such, they are similar to the human hip joint, as it comes with a ball-and-socket arrangement, similar to human anatomy.
Rotation and Planes
The ball joint allows for free rotation in two different planes simultaneously. However, if the ball joint works with a control arm and another ball joint, it works in three planes at the same time. This results in the car’s ability to give passengers a comfortable ride from the suspension and better control of the steering wheel.
Three-axis articulation requires having ball joints at both the top and bottom parts. It limits stopping power over control arm axes by allowing them to be in other positions than parallel when necessary. Once the control arm axes can move freely asymmetrically, the caster and camber angles are easily adjusted.
With current models, ball joints don’t directly control toe angle, but there must be four ball joints and steering linkage to set the toe successfully. The toe angle allows the wheels to be symmetrical while following the vehicle’s longitudinal axis.
Ball Joint Suspension
The ball joint suspension is adjustable, so manufacturers can make vehicles that are more stable and easier to control on the road. It also promotes a longer lifespan for the tires, as the movement is smoother.
The purpose of the ball joint is to ensure that the wheels can have flexible movement that cooperates with the suspension. The suspension and wheels have to work together to keep you safe while driving. Therefore, ball joints are used in the front-end suspension system of all modern vehicles, though high-end or luxury vehicles may also have ball joints in the rear suspension system.
Ball joints can also be used as tie rod ends and inner socket assemblies in vehicles.
Ball joints must be lubricated so that they can pivot easily. Many of them are sealed with lubricant inside, allowing for unlimited and nonstop lubrication.
Ball joints with a seal of grease fitting required more maintenance to lubricate the joints, though the lubricant was so thick, the seal could break after a few years or months. The problem with them was that routine maintenance is about 12,000 miles for newer models. Therefore, the sealed ball joint is used primarily on vehicles now.
Without lubricant, the ball joints can malfunction, which can result in an accident while on the road. Newer ball joints have lifetime lubrication, enhanced boot seals, and sintered metal bearings, all of which helps the grease stay inside.
It’s essential to know that ball joints can malfunction at about 80,000 miles onward. You can tell when the ball joint fails when hearing strange noises, such as clicks or pops. If the ball joint fails completely, you lose full control over the vehicle.