A sway or stabilizer bar prevents the body of the car from leaning too much and keeps the vehicle stable when driving in turns. Most of the cars have one sway bar in the front and another separate sway bar in the rear suspension. Some cars have only one sway bar in the front suspension. Sports cars have thicker sway bars for better stability when cornering.
A sway bar is connected via rubber bushings to the car body or frame in the middle. Outer ends of the sway bar are connected to the parts of the vehicle suspension that holds the wheel (struts or control arms). The part that connects the outer ends of the sway bar to the suspension component is called a sway bar link. In most cars a sway bar link has two small socket joints at each end.
Sway (stabilizer) bar link
Over time, the sway bar link joints wear out. The first sign of a worn-out sway bar link is a knocking noise coming from the suspension when driving slowly over road bumps. In rare cases, if the grease inside the sway bar link joints dries up, it may also create a creaking noise when the suspension is moving up and down.
The most obvious signs of bad sway bar links and bad sway bar bushings are
- Noise (clunking, knocking, rattling)
- Metallic Sound when going over bumps
- Excessive Body Roll
- Sluggish Turning
Sway bars act as a lever during a turn and transfer suspension travel from the outside to the inside wheel which keeps the vehicle more level, reducing body roll and maintaining traction for better handling. Since the bar twists to achieve this, the rubber bushings that hold the bar to the frame can become hollowed out or misshapen from the constant torque and the end links that connect the bar to the lower control arm or strut can also wear out at a fast pace.
Check the sway bar links and bushings while performing a regular service with the car on the lift. A worn-out sway bar link will show a free play when pushed up or down. An extremely worn out sway bar link can separate. This will cause your car to lean excessively in turns and feel less stable and secure on the road. A worn-out sway bar link must be replaced to keep your vehicle safe.
Is it necessary to replace both sway bar links if only one is bad? The answer is no, however your mechanic may recommend replacing both sway bar links because both links usually wear out at around the same rate and if one is bad, the other may go soon too.