3 Symptoms of a Bad Sway Bar or Link
In this article we will explain the function of the sway bar (or bars) on your vehicle and some of the most common signs of failure. Other terms you may have heard for this part include stabilizer bar, anti-sway bar or anti-roll bar.
We’ll also look at why sway bars and links go bad and how much it’s going to cost to replace them. But first, let’s quickly go over the differences between these two parts.
What Is a Sway Bar?
A sway bar is a solid or hollow steel bar attached with clamps and non-metallic bushings to the frame of your car.
The bar ends are each symmetrically bent at an approximate right angle to the bar centerline and are attached to the vehicle’s suspension elements (for example, to the lower A-frames or to the shock struts) with short links. More on these links in a moment. As the suspension moves up and down the links will twist the bar in proportion to the suspension movements.
What Are Sway Bar Links?
As mentioned above, the links attach the ends of the bar to the suspension. These links generally include self-aligning end fittings that allow each link to align itself with the bar end and with the suspension element it is attached to.
In some designs, the link ends attach to the bar with self-aligning rubber bushing-type fittings.
Bad Sway Bar Link Symptoms
The highest wearing parts on any sway bar installation will be the links. Here are three key symptoms that you will note when the links finally become worn out.
1) Noise When Turning
A low level clunking noise or rattle will be noticed when driving especially when going through a corner. The self-aligning fittings at the ends of each link have become loose.
2) Noise When Going Over Bumps
If symptom 1 above is not addressed a sway bar link can detach from the suspension or from the bar end. When this happens a loud clattering noise will be noticed when the car goes over a bump.
3) Vehicle Handling Worsens
There can be some degradation in the handling of your car when a sway bar link fails. The amount of lean when driving through a corner may noticeably increase because the bar is no longer doing its job.
Unless you’re the type that spends their weekend at their local track, on the Tail of the Dragon, or even the Nürburgring, you may not be sufficiently sensitive to notice this difference in handling. The noises described above will be the most obvious failure warning signs.
These symptoms must be addressed as soon as possible. The car can be driven for a few days with a failed sway bar link. You should slow down a bit more while cornering. And you should get the necessary repair work completed without delay.
What Is the Purpose of a Sway Bar?
I am confident that while driving, you have experienced how your car rolls (leans) to the outside of any corner. Turn left, the car leans to the right; turn right, it leans to the left. The faster you are driving, the more the car will lean in a corner. This behavior, even if not too extreme, can typically be uncomfortable.
It also can adversely affect the car’s handling because the lean and the accompanying motion of the suspension will change each tire’s alignment with the road surface. A tire that leans left or right will experience degraded grip to the pavement. You simply cannot go around any corner very fast in your car if it leans a lot in the turn.
These adverse handling effects can in part be mitigated by a properly designed sway bar. And the majority of cars built today will incorporate at least one and most likely two of these clever devices. One will be located at the front and one at the back.
The bars and how they mate to the car and to the suspension elements will have the following effect:
In a turn, as the car leans, each sway bar will apply a force downward on the suspension that’s on the outside of the turn. This combination of forces can be considerable and will assist in maintaining the car at a more level attitude when cornering.
Properly designed sway bars can almost completely eliminate the leaning or rolling effect when a car turns. This is a very remarkable benefit. And the sway bars do this while making the suspension just a little bit stiffer than would be the case if no sway bars were present.
Sway bars add to your car’s handling characteristics a quality called “roll resistance”. And this quality can be adjusted by the bar stiffness at each end of a car.
Automobile designers intentionally calibrate a car’s roll resistance, front to rear, to help improve its handling qualities. All of this is invisible to the car owner, but a car’s responsive handling and flat behavior in turns is generally pleasurable and confidence-inspiring for most drivers.
The Other Sway Bar Problem
This material can wear out and the bar will then become loose.
It will produce a rattling noise at different times while driving, but especially over a rough road surface. Also a loose bar can slide to the left or right and allow the links to misalign with the suspension attachment points. This can add to the audible clatter.
What Causes Sway Bar Links To Go Bad?
As with most everything else in life, sway bar links simply wear out due to age. The links generally have a rubber boot to preclude water and dirt entry to the link internal parts. This boot usually fails first, and then road grit and water gets into the link joint and wears it out.
How Long Do Sway Bar Links Last?
The links provided by the manufacturer on your new car will last a long time. Useful life of 150,000 miles is not unusual. Replacement parts, if not OEM (made by your car’s manufacturer), will usually not last nearly this long. And links that are made overseas tend to be even more prone to a shorter life.
If you are having the repair done by a private repair shop, you would be wise to specify that the replacement links they install be made by an American manufacturer. They will cost a few bucks more than the imported parts but will last far longer.