As we all know well, cars can make lots of annoying squeaking sounds every now and then. They can squeak while braking, or it might be the tires, or even windshield wipers. However, you can more or less isolate the problem for these issues easily.
When it comes to squeaking suspensions, the problem isn’t really that easy to fix or even pin down. This article will focus on what causes these squeaking noises, how you can pinpoint the exact problem, and how to get rid of them.
How Can I Recognize Suspension Squeaks?
If you drive on a bumpy road, or even if you happen to go over a speed bump, your car might make a quick creaking noise when it goes over the uneven section. Obviously, this is quite an embarrassing thing for a driver since most people on the street will turn around reflexively. However, embarrassment would be the least of your problems. If you even suspect that there’s a creaking sound coming from your car’s suspension, address it as soon as possible.
The Basics of Car Suspension
What Does Car Suspension Do?
Car suspension is extremely important. In fact, it’s roughly as vital to your car as the engine, brakes, and wheels.
For those of you who don’t know enough on the subject, the suspension is basically there to maintain the balance of your car. In ideal conditions, automobiles would run on straight, even roads with no bumps, holes, indentations, rubble, or any other obstacle. However, even the best-maintained roads out there have their issues and your car has to handle them if you want a smooth drive.
In short, a car’s suspension must do the following:
- Maximize friction between the tires and the road beneath them
- Provide good handling and solid steering
- Make sure the car remains roughly level during the whole drive
- Provide comfort and safety of the driver and the passengers.
Everything that makes up the suspension is found in the bottom part of the car’s chassis and its biggest part is the frame. This component supports all of the load that comes from the car, i.e. the engine, the body, etc. Directly connected to the frame is the suspension system, which we will cover in more detail in a bit. In very basic terms, this system dampens and absorbs shock, maintains the tire contact, and helps with the weight support.
At the front of the car is the steering system, linked to both the suspension system and the frame. By using this system, you’re able to move your car forward and direct it in any horizontal direction.
Tires are the final part of a car’s suspension. Their primary function is to keep the car in motion, but they also need to maintain the vehicle’s balance. They do that thanks to the friction and the grip on the road.
The Suspension System’s Components
You’ll find a spring in every car’s suspension system nowadays. As the car moves along a bumpy road, the spring either stretches or compresses. By doing so, it absorbs the kinetic energy that driving on an uneven road produces, keeping the car level.
There are various types of springs in use today. Historically, people first used the so-called leaf springs that consisted of several layers (“leaves”) of metal. Right now, you can find them on various heavy-duty vehicles like trucks. However, the most commonly used type is the coil spring because of its motion absorption capabilities. There are, of course, other types of springs out there.
Struts and Anti-roll Bars
A spring will definitely absorb the kinetic energy from driving on an uneven road, but it has to dissipate it in order to keep the car from bouncing uncontrollably. There are several ways that help the suspension system overcome this issue, one of them being struts and anti-roll bars.
A strut is a shock absorber that’s mounted inside of a coil spring. Not only does it help with dampening the kinetic output of the coil, but it also provides additional support for the whole suspension. Because of how vital the strut is to the suspension, you should treat it as a critical safety feature of your car and make sure that it’s not worn or damaged.
Anti-roll bars, also known as anti-sway bars, usually go hand in hand with struts and shock absorbers. These metal rods join each side of the suspension and run along the entirety of the axle.
Shock absorbers are an alternative to struts. They manage to dissipate the kinetic energy of the springs by converting it into heat thanks to their unique design. For example, an average absorber contains a piston that moves like an oil-pump. The oil moves out of the valves and holes for easier control of movement resistance.
What Causes Squeaking Noise When Driving Over Bumps
Now that we have a basic understanding of car suspension, it’s time to find out just what makes it squeak when you drive on those tiresome bumps.
A vehicle’s suspension system has lots of different components, and as you’ve just read above, each of them is vital to your car. For instance, if a coil is rusty or has any cracks, you need to replace it immediately. The same goes for a cracked anti-roll bar or a busted strut.
Shock absorbers tend to be the most frequent reason behind suspension squeaking, at least when it comes to the system components. There are various culprits for this noise and they depend on what type of absorbers your car uses. If it’s a hydraulic absorber, it might be leaking or have air problems. A spring absorber will suffer from the same issues that a regular spring might, i.e. rust and external damage.
Segments that make up the car’s suspension are all connected via joints. They are a pivot point between the wheels and the suspension and thanks to how they’re designed, they allow the wheels to move fluidly.
There are several types of joints out there. The most common is the rubber sleeve known as the bushing. This joint goes between the suspension component and the car’s frame, allowing the said component to rotate. If the bushing is worn, damaged, or broken, it will begin to creak.
Aside from ball joints, cars can also have regular rubber mounts and ball joints. As the name suggests, a ball joint contains a metal ball in a cup. This ball receives constant lubrication in order to avoid friction and provide more movement to the system. It’s used almost as often as the bushing, and it causes squeaking if there isn’t enough lubricating grease or if it gets old and loses its potency.
Rubber mounts, on the other hand, are only used in spots where you expect a small amount of movement. That’s why you will usually find them on the rear end of lower control arms. The squeaking can come from a tear in the rubber mount, so check it carefully for any damaged spots. In addition, spray a little penetrating oil and see if that helps stop the noise.
Steering Wheel Components
Interestingly, the creaking might not come from the suspension itself, but from other components related to it. For instance, the issue can arise from the steering wheel, or rather one of its components — the control arm. If it happens to be loose or damaged, it will cause a squeaking noise whenever you turn or go over a bump. However, pinpointing the squeak from the steering wheel is hard when you’re driving, so try to listen for it carefully to make sure where the noise comes from.
Lack of Lubrication
Most suspension components get lubrication automatically during the drive. However, both oil and grease can lose their lubricating properties after a while, or you might just have a leak somewhere. When rubber and metal components don’t get lubrication, lots of friction occurs and the parts start to wear down, causing the creaking.
Finding Suspension Noises
Most of the parts we’ve listed as potential sources have to move (and move in a specific way) in order to make that irritating sound. Even then it’s difficult to discern which side of the suspension it came from.
Fortunately, there is a method that you can use to find the suspension squeaks. The steps of this method are as follows:
- Make sure you parked your car on a level surface with no holes or bumps
- Block every single wheel; you need to be sure that the car won’t roll away as you test it for creaks
- Ask a friend or a family member to bounce all corners of your car; naturally, be sure that the body panel stays intact and suffers no external damage
- In order to create the squeak, you will need to move your car in particular ways, which include pulling, pushing, bumping, and bouncing
- Try turning the steering wheel with the car parked; if you hear a noise, it’s more than likely not from the suspension
- Check the wear level of your tires; a damaged bushing is usually on a tire which has more wear
How to Stop Your Suspension From Squeaking Over Bumps
Replace the Bushings and Rubber Mounts
Both of these components are made primarily of rubber. Therefore, if you spot any cracks or signs of wear, the best course of action is to replace them completely. You can do this by yourself; simply unscrew the cap, take the bushing out, replace it with a new one and screw the cap back on.
Depending on the level of damage, you might not need to actually replace a bushing or a mount. If there are minor signs of wear, simple lubrication might do the trick. Naturally, the best way to lubricate a bushing is to take it out, but you can also do it with the bushing still inside. All you need is a lubricant bottle with a long nozzle that reaches into tight spaces and holes.
Lubricate the Ball Joints
A typical ball joint already gets enough lubrication and it’s pretty sturdy. However, should the suspension suffer one hit too many, even these joints can be worn and damaged.
The easiest step is to apply more lubrication. But if there’s a leak due to a broken dust cover (also known as a rubber boot), you are going to have to replace it. Luckily, it’s not a difficult process. Simply get the old dust cover out, grease the joint up, then put it in a new cover.
When metal scrapes against metal or rubber, it causes friction and has squeaking as a nasty byproduct. Since coil springs tend to compress and expand often, this friction is inevitable.
You can reduce the noise that the springs make by lubricating their contact points with grease. However, if they show cracks or signs of wear, replace them at once.
Fix the Issues With Steering Wheel
Most of the solutions listed above are things that you can do in your own garage. After all, you simply need an appropriate product and you can reduce the noise by simply greasing the suspension up.
- Moly-fortified for increased film strength
- Fortified with extreme pressure additives for...
- Helps inhibit rust and oxidation
- NLGI #2 GC-LB lithium complex EP grease
However, broken or loose parts in the steering wheel or anywhere connected to the suspension are serious. As such, you will definitely need to take your car to a professional and have them look it over. Never try to disassemble your steering system, as it’s quite complex. One small error can make your problem ten times worse.
Was this article helpful? Did you find a solution to your own squeaking suspension or did we miss something? Please let us know in the comments below.