What Is Suspension In a Car and How Does It Work?

Vehicle suspension is the intricate system in your car that includes springs, shock absorbers, and linkages.

It connects your vehicle to its wheels, ensuring a smooth ride, stable handling, and good control. Understanding suspension is crucial for a comfortable and safe driving experience.

What is Suspension In a Car?

In a nutshell, your car’s suspension system is a protective lattice of shock-absorbing components such as springs and dampers.

Your car’s suspension helps ensure that your drive is safe and smooth by absorbing the energy from various road bumps and other kinetic impacts. Furthermore, it helps your tires stay in contact with the road by increasing tire friction.

Think of the suspension of your car as a kind of carriage on which the car’s main cabin sits. Your cabin is made more comfortable because it is sitting on the suspension, which is connected to the car’s wheels.

The vehicle and its cabin are insulated against impacts that are common when driving, even on well-paved roads.

The main parts of a car’s suspension include:

• Springs, which help to control the height and load of the suspension and cabin.
• Shocks (also called dampers), which absorb and dampen various kinetic energy impulses that your tires transmit when they contact the road.

Your car’s suspension system also likely has an anti-sway bar. The anti-sway bar can help to shift the movement of your wheels relative to your steering wheel. It effectively stabilizes your car’s direction as it moves along the road.

Your car likely has a suspension system for both its front wheels and its back wheels. Suspension systems can be either independent or dependent:

On the flip side, dependent suspension systems are used when wheel direction is bound by axle movement.

Independent suspension systems are used when your back or front wheels move independently of the front or rear axle, respectively.

What Does a Car Suspension Do?

Car suspensions are designed to help maximize the amount of friction between the tires and the road. This helps make car rides more comfortable, as well as ensure there is steering stability and good handling for the driver.

Roads are filled with imperfections, so a suspension system must be designed to handle these and support a vehicle. The suspension helps absorb energy from the tires to allow the body and frame of the car to remain stable.

The car’s ride is the ability to smooth out a bumpy road, and a car’s handling allows it to safely accelerate, corner and brake.

Principles known as road isolation, road holding and cornering are important to understand — and are why the suspension system is so important.

• Road isolation is how a vehicle is able to travel undisturbed over rough and bumpy roads.
• Road holding is the principle that tires need to be kept in contact with the ground, as this is what ensures you can steer, brake and accelerate safely.
• Cornering refers to the ability of the vehicle to travel a curved path while minimizing body roll.

The suspension system and the parts included in it help solve the challenges associated with those principles and help ensure a smooth and safe ride.

Why is your car suspension so important?

Any modern car is equipped with a suspension due to its advantages. For example:

• Suspension systems maximize the friction between your car’s tires and the road. By maximizing friction, you can steer your vehicle more stably and experience more comfortable handling. The more contact your tires have with the road, the safer and more confident you can drive.
• Your car’s suspension system also provides additional comfort. By limiting the kinetic energy transferred to your cabin from road imperfections such as bumps, you will experience much less bobbing and your passengers will also enjoy a smoother ride.
• In addition, suspension systems can help increase the life and durability of your car. Your vehicle’s components are subjected to much less stress over time by limiting how much energy is transferred from bumps and potholes in the road. Therefore, the other components of your car will last longer.

Parts of a Suspension System and Their Functions

#1. Springs.

Springs are the backbone of your suspension system. They absorb shocks and bumps, maintaining tire contact with the road. Coil springs and leaf springs are common types used in vehicles.

#2. Shock Absorbers (Dampers).

Shock absorbers, often simply called shocks, work in tandem with springs to control the rebound and oscillation of the springs. They ensure your ride remains smooth and stable by dissipating kinetic energy.

#3. Struts.

Struts are a structural part of the suspension system and serve multiple functions. They provide support to the vehicle’s weight, house the spring and shock absorber, and help maintain wheel alignment.

#4. Control Arms.

Control arms connect the wheels to the frame or body of the vehicle. They enable the wheels to move up and down while controlling their lateral movement.

#5. Sway Bar (Stabilizer Bar).

Sway bars reduce body roll during cornering. They connect the suspension components on each side of the vehicle, distributing force and enhancing stability.

#6. Bushings.

Bushings are small but critical components that dampen vibrations and reduce noise. They are found in various parts of the suspension system, including control arms and sway bars.

#7. Ball Joints.

Ball joints allow the suspension components to pivot and move. They connect the control arms to the steering knuckles and are essential for steering and control.

#8. Tie Rods.

Tie rods connect the steering system to the wheels. They play a crucial role in steering responsiveness and maintaining wheel alignment.

How does a car suspension work?

A suspension works on the principle of force dissipation which involves converting force into heat thus removing the impact that force would have made.

It uses springs, dampers, and struts to achieve this. A spring will hold the energy while a damper will convert it into heat.

The job of a car suspension is to maximize the friction between the tires and the road surface, to provide steering stability with good handling, and ensure the comfort of the passengers.

If a road were perfectly flat, with no irregularities, suspensions wouldn’t be necessary. But roads are far from flat. Even freshly paved highways have subtle imperfections that can interact with the wheels­ of a car.

It’s these imperfections that apply forces to the wheels. According to Newton’s laws of motion, all forces have both magnitude and direction. A bump in the road causes the wheel to move up and down perpendicular to the road surface.

The magnitude, of course, depends on whether the wheel is striking a giant bump or a tiny speck. Either way, the car wheel experiences a vertical acceleration as it passes over an imperfection.

Without an intervening structure, all of the wheel’s vertical energy is transferred to the frame, which moves in the same direction. In such a situation, the wheels can lose contact with the road completely.

Then, under the downward force of gravity, the wheels can slam back into the road surface.

What you need is a system that will absorb the energy of the vertically accelerated wheel, allowing the frame and body to ride undisturbed while the wheels follow bumps in the road.

The study of the forces at work on a moving car is called vehicle dynamics, and you need to understand some of these concepts in order to appreciate why a suspension is necessary in the first place.

Types of Car Suspensions

There are 8 Types of Car Suspensions as mentioned below:

• Multi-Link Suspension
• Rigid Axle Suspension
• Macpherson Suspension
• Double Wishbone Suspension
• Independent Suspension
• Rigid suspension
• Trailing Arm Suspension
• Air Suspension

#1. Multi-Link Suspension.

Multi-Link is a suspension developed by Double Wishbone and Multi-Link into a suspension that has a fairly complicated construction design because it has separate parts that are held together by joints.

This suspension also has component ends that pivot on two sides of the arm. Construction is made by manipulating the direction of the force that will be received by the wheel.

Multi-Link is a type of suspension that has a quality grip and with this suspension, controlling the car becomes easier. The Multi-Link suspension also has many variations.

If this suspension is damaged, then the replacement process takes a long time and the spare parts are still rare, so the price is relatively more expensive than other suspensions.

#2. Rigid Axle Suspension.

Rigid Axle suspension is usually placed at the rear of the car. The main feature of this suspension is its wheels on the rear left and right. The two wheels are connected into one axle which is commonly referred to as the axle.

The rigid axle suspension has 2 models at once, namely the Axle Rigid model which is equipped with leaf springs, and the Axle Rigid model which is equipped with a coil spring or often referred to as a spring.

This suspension has fairly good quality and can be applied in various types of cars. It is fairly simple because it can work with just one solid piece and is equipped with 2 springs.

The axle rigid is also considered a strong suspension, so it can support large loads stably, making it suitable for various types of large cars.

Suspension can help dampen the vibrations or shocks that occur when you are on a road that is uneven or tends to be bumpy. With a good-quality suspension car, you can stay seated without any disruption.

The suspension is not only useful to help reduce vibrations when the car is driving but can make handling safer and let the car can run stably on the road.

With its very significant use, of course, the suspension is a must-have component in a car and it must get extra care.

Now, there are many types of cars around the world and this makes a variety of suspension types available. Even the use of suspensions in each car brand is always different, due to a large number of quality suspensions.

Differentiating the type of suspension in each car brand is certainly a way to balance the type of car. At least several types of suspension are widely popular and used in cars produced nowadays.

#3. Macpherson Suspension.

Macpherson is a suspension whose name is taken from its inventor, Earle Macpherson. Lots of cars around the world use Macpherson suspension.

Many automotive manufacturers like this suspension, because it has an affordable price and also has fairly simple components.

The Macpherson suspension has an upright shape and is supported by shock absorbers which are used as the center point of the corner caster in the car. This suspension is also very easy to obtain because it’s distributed widely.

The disadvantage of Macpherson’s suspension is that it is less able to receive loads and the tilt angle always changes when the car is turned or turns, this makes the tires less able to grip the road asphalt properly.

#4. Double Wishbone Suspension.

Double Wishbone is a type of suspension that has 2 arms that support the suspension system, namely the upper and lower arms. With this suspension, the car can run stably.

#5. Independent suspension.

Independent suspension is a specially designed suspension because the right and left wheels at the rear are not connected directly but instead by axle joints

If the rear wheel steps on a hole, of course, the car will not rock and this is because only the left suspension moves. Independent suspension is indeed widely used in luxury cars.

The independent suspension has a more complex construction and the axle movements are mutually independent. This suspension is also equipped with two flexible joints. This type of suspension is still fairly expensive, so its use is mostly in luxurious cars.

#6. Rigid Suspension – Leaf Spring.

Rigid – Leafspring is one type of suspension that is widely applied in cars circulating in Indonesia and is mostly used in commercial-type cars or old-type cars. This suspension is usually used at the rear of the car because this suspension is stiff.

This suspension has a fairly simple and simple construction. This type of suspension usually consists of an Axle Housing that is intentionally tied using a U-Bolt already attached to the frame. Cars that use this suspension usually have a fairly high level of resistance.

#7. Trailing Arm Suspension.

Trailing Arm is a type of suspension whose instructions are almost the same as 3 Links – Rigid, even though the working system is very different. The way it works is also different from the 3 Links – Rigid or other types of suspension.

The Trailing Arm suspension has connected from the right side to the left. This type of suspension is usually placed at the back of the car.

#8. Air Suspension.

Air Suspension is one of the developed suspensions that has excellent performance, so this type of suspension is widely used in luxury cars.

Even in luxury cars, the car’s suspension can be adjusted using a computer and this allows the adjustment to be done properly.

The drawback of this suspension is that it has a very complicated construction when compared to other types of suspension. Not only that, but this suspension also has a very expensive price.

How can I tell if my car has suspension problems?

Different parts of the suspension system can wear out or become damaged. It’s important to pay attention to potential signs that a part needs to be repaired or replaced. Some common signs of suspension damage include:

#1. Pulling to one side when driving.

A car that’s pulling to one side when driving is a sign that your shock absorbers, tyres or brakes have seen better days.

To work out which the culprit is, you’ll have to do a bit of investigating. It might be something as simple as an under-inflated tyre, so try checking the tyre pressure before anything else.

Improper tyre alignment might be an issue, so you might want them looking at too. If you haven’t rotated your tyres in a while, then this may also resolve the problem.

If that still hasn’t cleared things up, then try taking a look at your shock absorbers. Notice any signs of wear or damage to them? It’s best to take your car to a qualified mechanic before anything gets worse.

#2. Bumpy rides are more common.

If driving on flat, paved roads is starting to feel like a World Rally qualifier, then take note. Feeling every rock, bump and hole means your shock absorbers or struts are probably on the way out.

To check, try giving your car the bounce test. To do this, push your entire weight down on your car’s bonnet. Release it and then count the number of times the car bounces. Any more than three bounces means there’s a problem with either your shock absorbers or struts.

#3. One corner sits lower than others.

A corner that sits lower than the others, accompanied by a clunking noise when going over a bump, could mean you have a worn or damaged spring.

To double-check, make sure your tyres are all properly inflated. If one corner still seems to be sitting lower than the rest, try pushing your entire weight down on the boot of the car.

What sound does the suspension make? A creaking or squealing sound is a tell-tale sign your suspension needs seeing to by a professional.

#4. Diving, rolling or squatting.

If your car dives forward when braking, leans or rolls to the side when cornering or squats backwards when accelerating then be sure to get it checked at a garage. As well as making for an unpleasant ride, it could also increase your stopping distance, which is very unsafe.

#5. Difficulty with steering.

Are you having trouble steering your car, even at low speeds? If so, it’s a sign your suspension system is lagging or your steering system is at fault. Try topping up your power steering fluid to see if that helps. You should check for worn or loose belts and damaged control arm bushings too.

Keep an ear out for squealing sounds too, as this may be an issue with your power steering pump. Driving a car when your steering isn’t working is dangerous, so have it checked by a mechanic as soon as possible.

#6. Oily shock absorbers.

If they’re in their proper condition, then your shock absorbers should be dry in appearance. But if they’re greasy or oily, then there may be a leak which could end up damaging your vehicle if it’s left untreated.

Replacing The Suspension

Replacing the suspension will take you about a day, but the question is, how do you know if something is wrong? There are some common tell-tale signs that should immediately urge you to go for repairs, and they include:

Rough rides.If you have used the car for a while, you know precisely how driving should feel. A faulty suspension will make it quite difficult to turn and brake, while every bump in the road will feel more impactful.

Drifting during turns. This is a significant problem as it’s not safe to drive a vehicle that drifts on turns. You should immediately notice the “floatiness”, which is a sign that your shocks are at fault.

Uneven tire treads. Generally, the tread wear should remain even. One side will have fewer treads than the other with a faulty suspension.

If or when you notice any of the above symptoms, the final amount you’ll spend on repairs will depend on what exactly went wrong.

The suspension has many components, and, thus, you can expect the check to be around $1,000-$5,000. However, it’s important to be aware of the more costly replacements and procedures:

• Shock absorber replacement: $200-$1,500
• Coil spring replacement: $550-$700
• Strut replacement: $50-$900
• Wheel alignment: $20-$400

Ultimately, your car’s suspension system is just one of the many crucial components required to ensure a safe ride whenever you hop in your vehicle. Without suspensions, vehicles would be bumpy at best and, at worse, hazardous.

Make sure that you keep your suspension system in good condition by periodically taking your car in for an inspection with a certified mechanic. We strongly suggest taking your vehicle in for repairs if your ride ever becomes too bumpy or you suspect that your suspension is possibly wearing down.

FAQs.