Q: What Is a Sway Bar and What Does It Do?

The sway bar on your vehicle is an essential part of the suspension. The sway bar may also be known as an anti-sway bar, an anti-roll bar, or a stabilizer bar, and all of these perform the same job. No matter what name it goes by in your vehicle, they all have the same function. It’s design is to keep the vehicle from swaying or becoming unstable during turns. Knowing a little about what is does can assist you in knowing if there is a problem with it and can help you make an informed purchase.

Your vehicle can have a sway bar on just the front suspension, or it can have it on the front and the rear. Many older vehicles did not come with sway bars, but most modern vehicles have them installed on the front and the rear. The sway bar extends from one side of the suspension to the other. For example, on the front of most vehicles, each end of the sway bar is connected to a moving part of the suspension such as the control arm or strut assembly. It is connected to the same point on both sides of the vehicle. The connection is done either with a bushing or a small ball joint known as a link pin. These all are for movement with the suspension. The sway bar is then connected to the frame or unibody using bushings.

The bar itself may seem solid but it is actually made of sprung steel so that it is not too rigid. What the sway bar does is keeps the vehicle as level as possible during side-to-side movements. When making a turn, your car will typically dip in the front corner of the vehicle that is going into the turn and lift on the outside corner. This can cause the vehicle to tilt and feel like it is going to roll over. With a sway bar, due to the connection from one side to the other, when the inside of the vehicle dips, it pulls down on the opposite side causing the vehicle to stay as level as possible. This makes the vehicle safer and also allows it to handle better. With sway bars on the front and the rear of your vehicle this will help it perform even better.

When you suspect a problem with the sway bar or with the vehicle’s suspension it is a good idea to inspect the sway bar system. The bar itself is a non-wear item, meaning that, unless it is hit, it will never wear out. The bushings or links that connect the sway bar to the rest of the vehicle needs to be routinely inspected. The bushings should be checked for cracking or bulging. If they have any oil on them, then they need to be replaced. A missing bushing should be replaced immediately. Link pins need to be checked for any sort of looseness or freeplay. If the links are not tight and firmly mounted, then they need to be replaced. These should alway be replaced in pairs.

On many vehicles you can also upgrade the sway bar for performance reasons. As I mentioned, the sway bar is essentially a spring bar, so it does flex. The smaller the diameter of the bar the more it flexes. Many people will install larger bars to make the suspension more rigid and firm during turns. It is important that you do not go too large as it can cause the vehicle to ride too rough and cause other suspension problems.

Overall, the sway bar and its related parts do not wear out or need to be replaced very often. These parts do not flex or move too much, so they tend to last for quite some time. The main thing that you want to keep in mind is that these and other suspension parts should be inspected routinely, or at every oil change to ensure that you do not experience any severe tire wear or other related problems. If any of these parts are to be replaced or upgraded, it is important to seek some professional advice so that you do not install any parts that you do not need or may regret purchasing.