It’s impossible to imagine cars as we know them today without suspension. Quite often, car suspension is mistaken to be solely responsible for ride quality. However, that’s far from the truth. Along with taking care of things like the ride quality, it’s also responsible for a car’s dynamics — that includes steering and the overall handling aspects.

What’s more, car suspension has evolved by leaps and bounds since the early days. The fact that it’s been continuously evolving isn’t the only noteworthy fact, it also has specific variations for different applications. Modern car suspension offers adjustability that can allow for tweaks that drastically impact a car’s characteristics. Despite it being a part of our lives, there’s still a lot that we common folk don’t know, especially when it comes to its workings.

Car Suspension — Where It All Began

Before we take a closer look at car suspension, its components, and how it works, let’s discuss where it all began. What you might find interesting is that suspension was invented and used well before motorized cars. There is research that suggests that chariots and carriages used suspension setups multiple centuries ago. While it’s a heavily dated form of suspension, the idea behind it was more or less the same.

Where things get interesting with advancements in suspension is in the late 1700s when the coil spring was patented for the first time. Interestingly, the development of this suspension tech started almost a century before the patent. It is said that Robert Hooke, an experimental scientist, and philosopher of the time discovered that an elastic body under stress changes shape proportional to the applied stress over a range. This discovery went on to be called Hooke’s Law.

It took another 100 years for the coil spring suspension tech to be put to use. The first application was an armchair produced in 1857. Many believe that the industrial revolution that took place during this period allowed for the mass production of components like the coil spring. 

Cars, however, continued to use leaf springs until 1906 when the ‘Brush Runabout’ became the first vehicle to make use of coil springs. Leaf springs were still widely used until 1934 as that’s when General Motors decided to make the switch to coil springs for the front suspension.

Types of Car Suspension

Car Suspension can be primarily divided into two types — independent and dependent. The majority of cars on the road today use the former, but there was a time when the latter was widely used. There are multiple variations of both car suspension types as well. While there is a third type called semi-dependent suspension, it’s highly uncommon. In this type, the movement of one wheel does affect the other, but they are not rigidly connected.

Independent Car Suspension

As its name suggests, independent car suspension is designed to let each wheel move upwards and downwards independently. What that means is the wheel on the right side can move up or down without affecting the wheel on the left. That being said, they aren’t completely disconnected as they feature sway bars to link them. This has many added benefits. One of the biggest is that the wheels aren’t forced to operate perpendicularly.

As a result of the independent nature of the car suspension, each corner of the vehicle handles potholes, bumps, and gradations independently. The only limitation to this car suspension setup was maintaining camber. Different types of independent suspension systems approached this hurdle in their way. Keep in mind, these types of independent suspension – like multi-link and wishbone – have certain advantages, but aren’t widely used as it’s not cost-effective. 

• MacPherson Strut
• Double Wishbone
• Swing Axle
• Sliding Pillar
• Multi-Link Suspension
• Semi-trailing Arm Suspension
• Swinging Arm

Dependent Car Suspension

The other type of suspension, dependent, is not as favorable as the independent type. This is because of a few shortcomings when compared to the independent type. 

The workings of a dependent car suspension are the opposite of an independent car suspension, where it doesn’t operate without affecting the wheel at the other end of the axle. Cars that use this system almost always feature a beam or a live axle that ensures both wheels are parallel and perpendicular to each other.

There are several disadvantages to this type of suspension. The biggest is how every end of the car is affected by a situation occurring at one end. What this means is that if there’s a pothole or a bump that one end experiences, it’ll pass it on to the other end as they are rigidly connected. This can upset the overall stability of a car. Furthermore, the connectivity of the wheels also affects the camber.

• Leaf Springs
• Satchell Link
• WOBLink
• Mumford Linkage
• Panhard Rod
• Watt’s Linkage

Main Components of Car Suspension

The best way to understand how car suspension works is by knowing its components and their purpose. For the sake of simplifying this article, we’ve stuck to the most widely used suspension — the independent type.

Spring

One of the prime components of car suspension has to be the springs. The use of springs took car suspension to the next level. Springs essentially act as reservoirs of energy. They absorb or collect the energy that is passed on to them when they compress. They compress undulation like potholes and bumps on the road. These springs return to their original state and release energy. The spring works in conjunction with the shock absorber to reduce the effect of uneven surfaces and maintain stability.

When we say springs, you are probably imagining circular coil springs, and you aren’t wrong. They are indeed the most common spring and the only one to fall under the independent type of car suspension. However, there are also leaf springs of the dependent suspension type which serve a similar purpose but aren’t nearly as efficient. Besides coil springs and leaf springs, there are torsion bars which can be considered to be the third alternative. Torsion bars fall under the semi-dependent car suspension type and can also be referred to as twist beams.

Coming back to coil springs, they feature a coil shape that has proven to be good for energy-storing. Another benefit of coil springs is that they are quite compact which helps with overall packaging. The performance of coil springs also depends on their spring rate. Simply put, the spring rate dictates how much pressure or force it takes to compress the spring. If you’re looking for quality coil springs, check our selection of products made by some of the best names in the business.

Shock Absorber

Shock absorbers or dampers are used along with springs in car suspension systems. While springs do a great job at collecting the energy or force, their design forces them to get rid of this energy and return to their original state. The force of the return would lead the spring to compress once again, almost in the form of a bounce. This bounce would then translate into a ride quality that would also be springy or bouncy.

The only way to stop the bounce would be by dealing with the energy in the springs. This is where shock absorbers come in. A shock absorber features a piston that moves inside an oil-filled cylinder. The shock absorber is compressed along with the spring, and it pushes into the oil and generates resistance against the coil spring’s tendency to bounce. As we mentioned earlier there are many variations of every part of car suspension. When it comes to the shock absorber they feature one tube or two in a concentric setup.

The shock absorbers feature narrow control passages and one-way valves in the piston. This is designed to restrict the oil flow from one chamber to another. It’s this restriction of oil flow that’s responsible for slowing down the bounce of the spring and stabilizing the car. Interestingly, some vehicles feature shock absorbers that use both oil and gas. These are not only more modern but have proven to be more efficient in overall performance as compared to conventional oil-filled shock absorbers. We stock some of the best shock absorbers on the market. Check our catalog for quality replacement options.

Linkage

Car suspension is made out of multiple parts that work together to deliver the ride quality and handling we’re used to today. These parts can work together because they are interconnected, and that’s made possible thanks to links. Links are what allow independent car suspension systems to carry out multiple tasks like absorption and steering at the same time. They can also be described as the frame of the suspension system. These links feature joints or bushings on either end that are designed to integrate different parts of the suspension. 

These joints usually feature a ball joint or a bushing to allow the components to pivot. Car suspension linkages separate themselves from control arms as they don’t offer as much movement. When it comes to the application of these linkages, a MacPherson car suspension setup uses around two links per wheel, while multi-link suspension systems use at least three links. 

Dependent car suspension systems don’t require linkages as most of the components are mounted directly on the solid or live axle. Control arms and wishbones are examples of linkages.

Ball Joint

Another important part of a car suspension is the ball joint. Ball joints help establish a connection between control arms and steering knuckles. This connection lets steering knuckles move in all kinds of directions. The knuckle doesn’t just move upwards and downwards but also side to side. Despite being one of the smallest parts of a car suspension, it’s incredibly important as it keeps the vehicle in control by ensuring smooth movement.

A ball joint is fairly straightforward in its construction. It has a stud that sits in a metal housing. This stud can rotate thanks to a specially designed socket that sits in the lubricated casing. The reason it’s called a ball joint is that one end of the stud is shaped like a ball. This ball-shaped side is what sits in the socket allowing for multiple degrees of rotation.

Knuckle

The most common suspension setups use two arms at each wheel. These arms connect to the knuckle at the top and the bottom. They connect to the aforementioned ball joints which allow for movement in various directions. The arms and ball joints work together to let the knuckle pivot while also ensuring that it remains in a vertical position.

The main purpose of the knuckle is to help connect the wheels to the steering system while making sure the rest of the car suspension system does its job. The knuckle uses a lateral arm that’s connected to the tie rod ends. The tie rod ends connect the steering rack to the knuckles which makes a car maneuverable. The tie rod ends, pushes, and pulls the knuckles to turn the front wheels. 

Anti-Roll Bar

One of the most simple parts of a car suspension is the anti-roll bar or the stabilizer. It’s a simple cylindrical bar that ties both ends of the axle together. Despite being an uncomplicated part, it serves quite an important role. What it does is mitigate the roll that would be experienced when a car turns. This role is a result of centrifugal force acting upon the vehicle. While the roll doesn’t sound like a huge problem, it can reduce stability and be discomforting for passengers.

The intensity of the anti-roll effect depends on the rigidity of the metal bar. The higher the rigidity the less the car will roll. However, added rigidity can come at the cost of ride quality which is why manufacturers design anti-roll bars with both ride quality and handling in mind. Many times, anti-roll bars offer adjustability that lets the user decide the effect of the anti-roll bar.

Spindle

The main purpose of the spindle is to allow the axle which is part of the drivetrain to operate. The axle is connected to the car suspension and wheels but needs to rotate with the help of the spindles. Spindles are designed to hold the hub of the wheels in place while supporting the wheel bearings.

Spindles are used on most types of car suspensions. When it comes to the popular MacPherson Strut, the spindle connects to two arms – positioned at the back and the front. With double wishbone suspension setups, the spindle is connected to the upper and lower arms. 

Do You Require Any Car Suspension Parts?

You’ve come to the right place If you are on the lookout for the right car suspension parts. The Newparts.com Shop has high-quality car suspension spares for an incredibly long list of vehicles. From small parts like ball joints to larger components like shock absorbers, we have it all! Furthermore, if you’d like to read the latest car reviews, fixes to common problems, and informative guides — check out our dedicated Blog section.