There are specific types of ball joints for the different types of suspensions. The ball joint is one moveable part of a control arm assembly. The control arm bushings are just as important as the ball joint. If the ball joint is worn, chances are that the bushings are just as worn as the ball joint. In the case of a strut suspension, the upper mount can receive as much wear as the ball joint. The shock absorber is also and important component in the stability of the suspension system. If the shock absorber is out of oil, there is no damping. This article is about the ball joint and its construction, types, wear and inspection.
Getting a Suspension
MacPherson Strut: The strut and coil over spring requires a follower-type ball joint lower control arm.
Short Long Arm (SLA): On this type of suspension with the spring connected to the lower control arm, they typically use a loaded lower ball joint and follower upper ball joint, or if the spring is connected to the upper control arm, they will use a follower on the lower and loaded upper ball joint.
If you use a prybar and brute strength, your inspection could be influenced by the bushings. The control arm of an SLA or strut-type suspension will have two bushings to allow the arm to move in a vertical motion and a ball joint to hold the steering knuckle. The ball joint also allows the steering linkage to turn the steering knuckle. The bushings are made of rubber or an elastomer, such as polyurethane. The purpose of the bushing is to isolate the control arm from the chassis of the vehicle to reduce vehicle noise vibration and harshness (NVH). The bushings absorb road shock by compressing and twisting. Rubber bushings are normally used as original equipment applications. Polyurethane bushings are used in performance applications and normally result in an increase of NVH.
Types of Ball Joints
A ball joint is made up of a housing, ball stud, bearings, end cover and Belleville washer or spring. A Belleville washer is a conical-shaped spring designed to be loaded in the axial direction. The joint is attached to a control arm by pressing the joint into the arm or riveting the joint to the arm. If the joint is pressed into the arm, it will require a special tool to remove the old joint and install the new one. Failed pressed joints can be difficult to remove because of corrosion between the control arm and joint. This is especially true where a steel ball joint housing is pressed into an aluminum control arm. When the joint is riveted to the control arm, the rivets are drilled out or cut with a air chisel. The new joint is replaced using bolts and locking nuts.
|On the left is a follower-type ball joint. On the right is a loaded ball joint. Using the arrows, write the corresponding number next to the correct component name from the choices below.
Note: Not all of the words will be used.
end cover spring
Note: The correct answers are provided to your instructor via the