Different vehicles use different type ball joints. Some suspensions push the stud into the joint. That is the portion of the ball opposite the stud supports the weight. Another design pulls on the stud, that is the stud-side of the ball is loaded. Both designs give good service.
Some ball joints have grease fittings and others do not. The rubber boot is the seal on both types and keeps grease in and water and grit out. Once the boot is busted, the joint will soon fail. Torn boots can also allow corrosion to weaken the stud. If the stud breaks, control of the vehicle will be loss.
Eventually ball joints wear out. A ball joint is considered worn out when the socket no longer holds the ball tightly. This allows side to side movement and causes wheel alignment to change. Tire wear is the most common symptom, but squeaks, pops, binding and shimmy can also result.
On many ball joints the stud will move in and out when unloaded. This is because the weight of the vehicle holds the ball firmly in the socket. With the load removed the ball may move up and down. This is NOT the sign of a problem as long as there is no side to side movement.
Things that lead to premature failure:
Over greasing the joint causing boot failure.
Forcing debris into the joint, by not cleaning the fitting prior to greasing.
Out of round tires quickly destroy ball joints.
Improper service that damages the boot.
Lack of lubrication.
Severe potholes and hitting curbs can bent the stud.
Symptoms of worn ball joint:
Tire wear
Squeaking, popping and creaking, especially on bumps and when turning
Shake or shimmy from the front wheels
Steering wheel does not return to center after a turn
If you suspect worn ball joints, let the professionals at AGCO check them for you. AGCO, it’s the place to go.
