Ball joints with Hove MOT
Ball joints, much like the human body, are the mechanical version of a hip joint; a ball sits inside a cup (trapped) in order to allow the joint to move in numerous directions without becoming detached.
Also like the human version, a ball joint can become worn through use and can develop flat spots or become loose, the joints are often protected by grease filled rubber socks that can deteriorate or split allowing the lubricating grease to escape, therefore, the joint will become dry, possibly rust and fail to move correctly or become very noise or break.
Here are some diagrams showing ball joints used in different parts of the car:
During the MOT test, depending on whether or not a manual or an automated test is being carried out, all of these joints are tested, on an automated test lane the car is placed on a machine that puts the front wheels through a variety of different stress tests, this shows any excessive movement within the various joints.
On a manual MOT test, a similar process is carried out by two men with an iron bar that is used to apply pressure on the individual joints.
Clunking noises are the most common tell tale signs of a worn ball joint, another common fault being a broken coil spring in the suspension assembly.