If you hear a knocking or clunking sound when driving over bumps, it might be because your car’s sway bar links (also known as stabilizer links) are worn out or broken.
Sway bar links play an important role they connect two parts of the suspension (the sway bar and control arm) together. As such, you’ll want to replace a broken sway bar link as soon as possible.
What Is a Sway Bar?
A sway bar is part of your vehicle’s suspension, which includes your wheels/tires, springs, shocks, steering system, linkages, bushings, and joints. Sway bars help your ride handle turns and prevents body lean, the last thing you want while operating a motor coach or RV!
At its core, a sway bar is really just a torsion spring a piece of metal that reacts to a twisting movement. When your vehicle turns, the sway bar works to level everything out and fights that tilting feeling you may have experienced when taking a corner too fast.
The number and variety of sway bars depend on the vehicle, and the actual bar attaches across the vehicle’s body from one wheel to the other.
What Does A Sway Bar Do?
As mentioned above, the purpose of a sway bar is to prevent body lean in the vehicle, typically caused by turning. When a vehicle especially a large vehicle like a truck or motor coach turns, force is distributed to the outside (if you were turning right, force and weight would be naturally shifted to the left.) This typically causes the outside tire to lift higher than the inside tire. But, with a sway bar, tires are brought back to the same level, thus leveling the entire vehicle.
As a torsion spring, the sway bar reacts to the twisting movement (again, most commonly experienced in turns) and levels your vehicle’s wheels. On the flip side, if both tires hit something at the same force, there would be no need for a sway bar because there would be no twisting motion.
The most obvious reason why sway bars are important is to ensure your vehicle doesn’t roll too much when handling turns. Aside from safety, sway bars help prevent lopsided wheel alignment and work to maintain an overall better grip on the road.
When to replace sway bar links?
A sway or stabilizer bar prevents the car body from leaning too much and keeps the vehicle stable when driving in turns. Most cars have one sway bar in the front and another separate sway bar in the rear suspension. Sway Bar LinkSway (stabilizer) bar link. 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 ball joints at each end.
Over time, the sway bar link ball joints wear out. The first sign of a worn-out sway bar link is a knocking noise from the suspension when driving slow over road bumps. In rare cases, if the grease inside the sway bar link joints dries up, it may also make a creaking noise when the suspension is moving up and down.
Your mechanic can check the sway bar links 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.
How to Change a Sway Bar Link?
Note: Refer to your car’s owner’s manual or a service manual to find out the size of sway bar links you need to replace the old, worn-out ones.
Step 1: Engage the parking brake. Set the parking brake on the vehicle and set the wheel chocks on one of the tires you are not removing.
This is for safety and will ensure the vehicle will not roll.
Step 2: Loosen the lug nuts. Using the lug wrench, loosen the lugs on the tires that need to be removed slightly, but do not remove them.
Step 3: Raise your vehicle. Find the lift point on your vehicle and raise it using the jack.
Lift points are the locations designated by the manufacturer where it is safe to raise your vehicle. Lift points are different for every vehicle and can be found in your vehicle’s owner’s manual.
Step 4. Secure the vehicle. Once the vehicle is raised, place a jack stand in a secure position on the suspension arm where the sway bar link is attached and lower the vehicle onto it.
This is important because the sway bar is a load-bearing part. Setting the jack stand in this way compresses the suspension and relieves the pressure from the sway bar link.
Leave the jack slightly touching the lift point while still keeping the majority of the vehicle’s weight on the jack stand.
Step 5: Remove the tire. At this point, remove the lug nuts completely and then remove the tire from the vehicle.
Step 6: Locate the sway bar link to be replaced. Sway bars are usually located at the front of the car and are bolted to the suspension on your vehicle.
Depending on the make and model of your car, you may have only front sway bars links or front and rear sway bar links.
Step 7: Remove the lug nuts. Two lug nuts hold the sway bar link in place. Start by removing the upper nut first. This nut holds the most weight when the sway bar is at normal rest, so it tends to be the most problematic.
Once the top nut is removed, remove the lower nut.
Tip: For rusted or frozen nuts, spray them with penetrating lubricant and allow a few minutes for the lubricant to take effect. This will make the job a bit easier.
Step 8: Apply pressure on the sway bar. Once both nuts are removed, take your pry bar and apply pressure on the sway bar close to the link.
This will relieve any remaining pressure on the sway bar link and allow you to remove it.
Step 9: Make sure the new sway bar link matches the old one. Use the pry bar to apply pressure down on the sway bar and install the new link in place of the old one.
Make sure the direction of installation is correct as the ends can look very similar.
Once the link is in place, install the nuts and tighten them to the appropriate torque specification. Refer to the owner’s manual of your vehicle to find the correct torque specification for your car.
Step 10: Install the tire back on the vehicle. Tighten the lug nuts as much as possible, but don’t overdo it. Putting excessive pressure on the car can knock it off the jack stand.
Once the lug nuts are snug, remove the jack stands and lower the vehicle slowly using the jack.
Step 11: Tighten the lug nuts. Once the vehicle is back on the ground, tighten the lug nuts to the appropriate torque specification.
If you are changing more than one sway bar link, simply repeat the steps on the other side.
How Long Does It Take to Replace Sway Bar Links?
As long as a vehicle doesn’t have severe rust and corrosion, replacing a pair of sway bar links is usually a pretty straightforward job. On most vehicles, a professional can complete the task in under an hour.
Why Would a Sway Bar Link Break?
In most instances, sway bar links simply wear out due to time, miles, and use. But the links can also break due to rust and corrosion, or metal fatigue. It’s also possible for worn control arm or sway bar bushings to over-extend the links, causing them to break.
What Does a Sway Bar Link Do?
Sway bar links connect the sway bar to the control arm. There is one link at each end of the sway bar.
The sway bar (also known as a stabilizer bar) itself is basically a large-diameter steel bar designed to prevent body roll during cornering. When the car is traveling over bumps, the stabilizer bar also provides a certain level of stability.
Most modern vehicles have both a front and rear sway bar, as well as front and rear sway bar links.