The sway bar (also called the anti-roll bar) is one of the more critical suspension components when it comes to the stability of your vehicle. It is connected to the suspension with sway bar links and rubber bushings.
The symptoms of bad sway bar links include poor handling (especially when turning), uneven tire wear, clunking, squeaking or rattling noises when moving over uneven surfaces or speed bumps.
The sway bar is responsible for keeping the vehicle stable. Its function is to disperse the forces on suspension components evenly across the entire suspension and subframe.
The sway bar is normally attached to the vehicle with rubber bushings and sway bar links. It is usually these bushings and links that cause the problems and symptoms and not the sway bar itself.
Symptoms of bad sway bar links
Typical sway bar links have a life span of approximately 50,000 miles, depending on how the vehicle is driven and factors such as weather and road conditions.
Just like with other worn suspension parts, worn sway bar links can badly affect handling and will usually make some strange noises when the vehicle is moving.
The sway bar and its links and bushings are very easy to check, and are usually the first suspension parts I will look at if I suspect that there is a problem with the suspension.
Before you jack up your vehicle, here are a few of the most common bad sway bar link symptoms to watch out for.
1. Clunking noise when going over speed bumps (or potholes)
The most common tell tale sign of worn out sway bar links or bushings is a clunking noise from the suspension. This particular sound is normally heard when you are driving over speed bumps, off a kerb or over some really uneven road surfaces.
It is usually caused by loose sway bar bushings that are no longer holding the sway bar tightly in position and are not preventing it from moving up and down. When you go over a bump at speed, the sway bar bounces against the subframe and worn sway bar links move around more than they should, producing the clunking sound.
It's worth noting that this noise can also be caused by worn control arm ball joints and worn shock absorber (or strut) mountings.
2. Unexpected handling characteristics
Worn sway bar links will affect how your vehicle handles, especially when turning corners or driving on roads with bends.
The job of the sway bar is to improve grip and cornering control by transferring some of the weight to the inside wheels of the vehicle when cornering. It does this by resisting the twisting force that is being applied to it, and transferring this force to the inside wheels.
If the sway bar links and sway bar bushings are worn, then this will severely impact the ability of the sway bar to absorb the forces that are being applied to it. This will result in unexpected handling characteristics and can increase understeer or oversteer, depending on whether the worn drop links are on the front or back sway bar.
3. Squeaking noises coming from the suspension
Another very common symptom of bad sway bar links is a squeaking noise coming from the tire area when driving over rough surfaces or speed bumps. This can be especially noticeable during hot, dry weather.
As the rubber bushings in the sway bar links wear down over time, they also become hard and will dry out. When you are driving, the rubber bushings will move in response to the movement of the car. If they have dried out, they will squeak as they move against the metal suspension parts.
The only way to resolve this problem is to replace the worn out sway bar links and bushings. You can apply some silicone grease to the rubber bushings to temporarily stop the squeaking noises, but this is only a short term fix and for safety reasons you should always replace worn out suspension parts as soon as possible.
4. Sway bar links are Visibly worn out
Sometimes bad sway bar links will look and feel worn out. The rubber bushings and nuts at both ends of the link can become hard, torn and lose their rounded shape.
Another sign of worn out sway bar links is when they become loose and you can move them around with your hand. Sometimes, they will even become detached from the sway bar or from the control arms.
How to diagnose bad sway bar links
The best way to diagnose bad sway bar links is to jack up the vehicle and physically inspect the links and bushings.
The most common places for wear and tear are at the sway bar link joints where they attach to the sway bar and to the control arm.
It's also very common for the sway bar bushings to wear out. The sway bar bushings wrap around the sway bar and are located underneath the brackets that secure it to the subframe.
In order to inspect the sway bar links properly you will need to jack up the front or back of the vehicle (depending on which sway bar you are inspecting). To ensure that the sway bar is free from tension you will need to raise both wheels off the ground on the chosen axle.
For this explanation, I will explain the procedure for inspection of the front sway bar. The front sway bar is usually more exposed than the rear one and is easier to inspect. Depending on your vehicle, there may or may not be a rear sway bar present.
You should only carry out the following procedure if you are qualified to do so. Refer to your vehicle handbook for the correct jacking point positions and procedures before you lift your vehicle with a jack. If you are in any doubt take your vehicle to a qualified mechanic.
- Start by loosening the wheel nuts on the two front wheels. You'll need to remove both front wheels to get good access to the sway bar.
- Jack up the car and secure it in place using suitable jack stands. Remove the two front wheels.
- Locate the sway bar links. They are the short thin metal bars that are positioned vertically behind or to the side of the brake rotor.
- Clean any dirt or debris from the sway bar links using a clean cloth. Check that the nuts holding the links in place are present and tightly secured.
- Starting on the driver side, grip the sway bar link with two hands and try to move it from side to side or up and down. The link should be held rigidly in place and should not move much. Excessive movement usually indicates wear of one or both of the ball joints.
- Repeat the process on the passenger side. If both links feel secure but you still suspect that they are worn then the next step is to remove the top nut that holds the drop link onto the sway bar. Sometimes it can be difficult to get any movement from the drop link whilst it's attached at both ends.
- With the top nut removed, move the ball joint around by gripping the threaded bolt attached to it. The ball joint should be stiff and should need some force to move it around. If it's not stiff then you need to change the sway bar link (they are also called drop links if you are ordering replacements).
- Whilst checking the sway bar links, it's also a good idea to check the sway bar bushings too. These will wear out on most vehicles over time and usually have a life span that is a lot lower than other suspension parts (usually around 50,000 miles). They often look like they are in good condition but fail to hold the sway bar in place when put under pressure.
- Start by visually checking the condition of the bushings. Clean away any dirt and check that the bushing brackets are tightly secured to the subframe. Next, check that there are no visible gaps between the bushings and the sway bar.
- If the sway bar bushings look ok, then remove the top ball joint nut on both sway bar links. This will release the sway bar so that you can wiggle the sway bar on both sides to check that it is held firmly to the subframe by the bushings and brackets. If it moves around too much then the bushings will need to be replaced.
Sway bar link replacement costs
Sway bar links usually cost between approximately $20 and $50 each to buy. Sometimes they are sold in pairs and sometimes the driver side part will be different to the passenger side part, so take car if ordering online.
If you plan on getting a mechanic to do the job for you, you can expect to pay at least $180 to $200 to get one set of sway bar links replaced. If you're not sure which suspension parts are causing the symptoms then