A sway or stabilizer bar is a component that prevents the car body from leaning excessively and keeps the vehicle stable during driving in turns. Most vehicles have one sway bar in the front and yet another bar in the rear suspension while some cars have only one sway bar in the front suspension. Sports cars actually do have thicker sway bars that offers better stability when taking a corner. A sway bar is connected through rubber bushings to the vehicle frame in the middle. The outer ends of the sway bar are attached to the parts of the car suspension that holds the wheel (struts or control arm system). This component that links the outer ends of the sway bar to the suspension component is called a sway bar link. In most instances a sway bar link has two small ball joints at each end. In the course time however, the sway bar link ball joints wear out. The first observable sign of a bad or worn out sway bar link is a knocking noise from the suspension parts during a slow ride over road bumps. This can be checked out by the mechanic while performing a regular service with the car pushed up on the lift. A bad or worn out sway bar link will give out or produce a knocking noise when pushed up or down, back and forth. However, an extremely worn out sway bar link can even separate. This situation always causes your car to lean too much in turns and feel very unstable and insecure on the road during drive. A worn out sway bar link needs to be replaced immediately to keep your vehicle safe and road worthy.