What is Car Suspension?- Definition, How does It Work

What is a car Suspension System?

Suspension is the system of tires, tire air, springs, shock absorbers, and linkages that connects a vehicle to its wheels and allows relative motion between the two. Suspension systems must support both road holding/handling and ride quality, which is at odds with each other.

The tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible because all the road or ground forces acting on the vehicle do so through the contact patches of the tires.

The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of the front and rear suspension of a car may be different.

Why is your car suspension so important?

Your car’s suspension system is responsible for smoothing out the ride and keeping the car in control. Specifically, the suspension system maximizes the friction between the tires and the road to provide steering stability and good handling.

The suspension system also provides comfort for passengers to limiting the impact of particular road conditions to not only the car, but the passengers riding inside.

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The suspension system is made up of several components, including the chassis, which holds the cab of the car. The springs support the vehicle weight and absorb and reduce excess energy from road shocks, along with the shock absorbers and struts. Finally, the anti-sway bar shifts the movement of the wheels and stabilizes the car.

Your car’s suspension system must be in good condition. Worn suspension components may reduce the stability of the vehicle and reduce driver control, as well as accelerate wear on other suspension system components. Replacing worn or inadequate shocks and struts will help maintain good ride control, as they:

  • Control spring and suspension movement
  • Provide consistent handling and braking
  • Prevent premature tire wear
  • Help keep the tires in contact with the road
  • Maintain dynamic wheel alignment
  • Control vehicle bounce, roll, sway, drive, and acceleration squat
  • Reduce wear on other vehicle systems
  • Promote even and balanced tire and brake wear
Car Suspension

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 to 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 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.

Parts of Suspension System

Following are the Parts of Suspension:

  • Wheels and tires
  • Springs
  • Shock absorbers and struts
  • Linkages
  • Bushings, bearings, and joints
  • Steering system all types
  • Hydraulic power steering
  • Electric power steering

1. Wheels and tires

Tires aren’t always considered part of the suspension, but they’re arguably the most important component of it. It provides traction for acceleration, braking, and cornering, and absorbs small bumps.

Tires wear over time, and are subject to cuts and punctures from hitting sharp objects, and to slow or sudden leaks from impacts. On the other hand, wheels fail (from bending or cracking) much less often, usually only in response to hard impacts from accidents or hitting potholes.

2. Springs

Every car and truck today has some sort of mechanism to absorb large bumps, and this always includes some form of spring, a metal part that bends in response to force. (A few cars over the years, particular those made by Chrysler, have used torsion bars metal rods that absorb impacts by twisting instead of bending instead of coil or leaf springs, but these are all different forms of spring.)

Springs can sometimes break when the vehicle hits a bump very hard, and many will sag eventually (after many years), but in general these parts are much less prone to failure than most other suspension components.

3. Shock absorbers and struts

While springs absorb the bumps, shock absorbers (or, in cars that have them, struts, which are similar to shocks) dampen the motion of the springs after a bump, keeping the vehicle from bouncing excessively.

Shocks and struts are filled with a thick oil, and over time the oil can leak out, causing the shock or strut to fail. Impacts and accidents can also cause leakage or can damage delicate internal parts.

4. Linkages

Every suspension includes various rods and other connecting pieces that collectively keep the wheels where they’re supposed to be relative to the rest of the vehicle. Most of these linkages are solid metal parts that rarely fail except in major accidents.

However, sometimes linkages and associated bushings are sold together, and the failure of a bushing can necessitate replacing the whole assembly.

5. Bushings, bearings, and joints

Because most parts of any suspension must be movable, the various linkages are connected by flexible connections. These include bushings and bearings, which are connections that allow a small amount of twisting or sliding, often without needing lubrication, and joints, which in automotive applications often use a lubricant such as a grease to allow for controlled movement.

Some suspension bushings are made of rubber, which can become brittle or break over time, leading to failure. Many joints tend to wear out, leading initially to looseness and eventually to failure.

A couple of the most common culprits are tie rod ends, which are lubricated joints that connect certain steering linkage parts, ball joints, which are found in both the steering system and attached to the control arms, and the bushings that separate the control arms from the vehicle’s frame.

6. Steering system all types

Every steering system contains numerous linkages, some joints such as the tie rod ends mentioned above, and some sort of steering box, the mechanical device that converts rotation of the steering wheel into the movement of the car’s wheels.

In general, linkages aren’t very likely to fail, while components such as tie rod ends are. Steering boxes wear out eventually, with rack-and-pinion steering systems in vehicles equipped with hydraulic power steering being the most failure-prone.

7. Hydraulic power steering

Many vehicles are equipped with power steering. Of the two types of power steering, hydraulic systems (i.e., those that use a high-pressure fluid to help the driver turn the wheels) are more failure-prone. Fluid can leak from high-pressure lines, delicate valves occasionally wear out, the belt that drives the power steering pump can loosen or break, and eventually, the pump itself may fail.

8. Electric power steering

More and more power steering systems found in modern cars and trucks are electric, not hydraulic. Electric power steering systems include various sensors, wires, and actuators (motors), any of which can fail, but luckily such failures are less common than failures of hydraulic components.

Types of Suspension system

There are 8 Types of Car Suspensions as mention 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.

Signs Your Car Needs Suspension Repair

Our vehicle’s suspension system (i.e., shocks or struts) is something we often take for granted. However, after supporting several tons of metal year after year, eventually, the shocks will wear out and suspension repair will be necessary.

Some people mistakenly believe the suspension is mainly about having a smooth ride, and therefore these repairs aren’t as important as other maintenance issues like oil changes or brakes. However, having a bad suspension can greatly affect your ability to control the vehicle, especially when stopping or turning, so it’s in your best interest not to ignore this part of auto maintenance.

How do you know when it’s time for suspension repair? Your vehicle will usually tell you. Here are six things to watch for.

1. Car rides roughly

Most people can tell their shocks or struts are wearing out when they begin to feel every bump in the road, or when every bump causes the vehicle body to “bounce.” A rough ride is an obvious sign that your vehicle’s suspension needs work.

2. Drifting or pulling during turns

With a failing suspension system, you’ll often feel the vehicle “drift” or “pull” when you’re turning. This basically means the shocks are no longer keeping the vehicle body stable against the centrifugal force of a turn, increasing your risk of a rollover. If you feel this sensation while turning, it’s time to take the car to a trusted auto repair shop for servicing.

3. Dips or “nose dives” when stopping

When the shocks are worn out, you’re likely to feel the vehicle body lurching forward and downward nose-first when you apply the brakes firmly. This can actually affect your ability to stop the car quickly (a bad suspension can increase stop time by up to 20 percent).

4. Uneven tire treads

Take a look at your tires. If you notice the tread is wearing down unevenly on your tires, or if you notice balding spots, this is often a symptom that the suspension isn’t holding the car evenly, and therefore putting uneven amounts of pressure on the tires.

5. Damaged, “oily” shocks

If you can look under the vehicle, take a look directly at the shocks or struts. If they look greasy or oily, there’s a good chance that they are leaking fluid and therefore aren’t working properly. It’s probably time to get those shocks replaced.

6. Try the “bounce test”

If you suspect your suspension is going bad (perhaps due to one or more of the symptoms we mentioned above), try this simple test. With the car in “park,” press down on the front of the vehicle with all your weight, “bounce” it a few times, then release. Do it again on the rear of the vehicle. If the car continues to rock or bounce more than 2-3 times after you release it, the suspension is wearing out.

FAQs.

What is a car suspension?

The suspension is the system of tires, tire air, springs, shock absorbers, and linkages that connects a vehicle to its wheels and allows relative motion between the two. Suspension systems must support both road holding/handling and ride quality, which is at odds with each other.

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.

What are the parts of Suspension System?

Following are the Parts of Suspension:
1. Wheels and tires
2. Springs
3. Shock absorbers and struts
4. Linkages
5. Bushings, bearings, and joints
6. Steering system all types
7. Hydraulic power steering
8. Electric power steering