Updated at: 03-08-2023 - By: Lucas

Your car or light truck is equipped with shock absorbers, but do you really know what they are and how they work? In this article, we’ll take a closer look at shock absorbers, what they do, and why you should care.

It’s one of the most important components of your vehicle, yet many owners don’t even think about it until something goes wrong. Don’t let that be you!

If you can understand how shock absorbers work, you can do a simple check to make sure they’re working properly and prevent expensive repairs down the road.

Types of Shock Absorbers

Hydraulic Type Shock Absorber

Hydraulic Type Shock Absorber

A hydraulic shock absorber is one of those things you never think about until it’s not there any more. When you hit a bump or a pothole, your car will jolt forward and then back.

This is because the shock absorbers are working hard to absorb the impact and reduce the force of the blow. Without them, your ride would be harsh and uncomfortable. But, with the hydraulic type shock absorber, all of this is taken care of for you.

It has a piston that is attached to the underside of the vehicle that is forced against the inside of the tube. As the car moves forward and backward, the piston and the tube are forced together and apart. This creates a dampening effect that absorbs much of the jarring motion.

The result is a smoother and more comfortable ride.

Double Acting Shock Absorber

Double Acting Shock Absorber-1

A double acting shock absorber has two chambers. One chamber is filled with a gas (usually nitrogen) and the other is filled with oil.

As the car encounters a bump or other unevenness in the road, the oil moves to the top of the shock and then back down again when the road is level. This oscillation of the oil helps to dampen the effects of the bump.

The gas works in a similar manner, but it works on a much faster time scale. When the car encounters an unevenness in the road, the gas moves to the top of the shock and remains there until the road is level again.

This quick movement of the gas works to quickly reduce the severity of the impact.

Single Acting Shock Absorber

Single Acting Shock Absorber

A single acting shock absorber is a type of shock absorber that has only one compression chamber. This type of shock absorber is usually used in rear-wheel drive vehicles with independent suspension.

It is also used in some four wheel drive vehicles. This shock absorber works on the principal of a dual-tube shock absorber with a single-acting valve in each tube.

A single-acting shock absorber will have a check valve in one tube and a spring in the other. When the pressure builds up in the one tube, the spring in the other tube forces the check valve to close and prevents the pressure from building up in the other tube.

When the car hits a bump or goes over a pothole, the pressure in the one tube increases which causes the check valve to open and release the pressure. Then, when the vehicle hits a level surface, the pressure in the other tube decreases and causes the spring to force the check valve to close again and prevent the pressure from decreasing.

This process continues until the pressure in both tubes are equalized.

Friction Type Shock Absorber


A friction type shock absorber is a device that uses the force of air pressure to absorb and dissipate the impact force of the suspension system.

This allows for smoother, more comfortable rides and less fatigue for the driver. Friction type shock absorbers are typically located at the bottom of each wheel well and they use a valve to control the flow of air.

As the vehicle travels over bumps, the valve opens up and allows air to escape from under the tires. This causes the tire to compress slightly and the shock absorber to work to restore the original size of the tire.

Friction type shock absorbers are typically made out of a soft rubber and they have a steel rod running through them.

The steel rod is what actually interacts with the valve and controls how much air is allowed to escape from under the tire.

Lever Type Shock Absorber

Lever Type Shock Absorber

A lever type shock absorber is a mechanical device that works in conjunction with the suspension of your vehicle. When you drive over a bump, the lever inside the shock absorber is forced outwards.

This causes the piston inside the cylinder to compress a small amount of fluid. As the piston compresses the fluid, it begins to exert a counteracting force that pushes the piston back into its original position. This action absorbs a large portion of the impact and prevents the jarring of your vehicle. The end result is a smoother ride.

Lever type shock absorbers are much more effective than coil type shock absorbers. A lever type shock absorber will provide a far more comfortable ride. That’s because it has a greater surface area than a coil type shock absorber. It is also easier to retrofit into an older vehicle.

In fact, most older vehicles have lever type shock absorbers already.

Telescopic Type Shock Absorber


A telescopic type shock absorber is a shock absorber with two telescoping tubes. One tube is inside the other. The inner tube has a piston attached to it.

As the wheel moves up and down, the piston moves up and down inside the inner tube. This piston is connected to a shaft which is connected to a valve. When the valve is open, it allows fluid to flow from one side of the piston to the other.

This creates a cushioning effect for the wheel. As the shaft turns, the valve adjusts itself to allow the proper amount of fluid to pass through.

This type of shock absorber is commonly used on low-priced vehicles. It is very simple and effective. However, it does have one drawback.

The shaft that connects the two tubes can get quite hot. This makes the shock absorber less effective and can even cause it to malfunction. On high-priced vehicles, a hydraulic type shock absorber is used.

These are more expensive than the telescopic type, but they last much longer. Plus, they don’t have the hot-shaft problem.

 Twin-tube Shock Absorbers  (Basic Twin-tube)


A twin-tube shock absorber has two tubes running side-by-side within the same housing. One tube is connected to the wheel and the other is connected to the vehicle.

As the wheel moves up and down, the movement is transmitted to the other tube. This causes the shock absorber to compress or extend, which makes the wheel move up and down more smoothly.

Twin-tube shock absorbers work very well. However, they do have one drawback. They have a tendency to “bound” when they are extended too far. When this happens, the wheel will jump up and down with a lot of force. This can damage the tires, the wheel and the vehicle.

A twin-tube shock absorber with a reservoir also prevents this from happening.

Twin-tube Gas Charged

A twin-tube gas charged shock absorber is a device that uses two tubes filled with gas, one inside the other. The inner tube contains a chemical that reacts with the gas in the outer tube.

As the wheel moves up and down or side to side, the inner tube moves up and down or side to side within the outer tube. This creates a dampening effect on the movement of the wheel.

The gas in the inner tube is compressed or expanded depending on the direction of movement of the wheel. This causes the inner tube to move up and down or side to side within the outer tube. This creates a dampening effect on the movement of the wheel.

Twin-tube shock absorbers are used on all kinds of vehicles, but they are especially important on those types of vehicles that have a lot of suspension movement. These include sports cars, sedans, SUVs and light trucks.

They are also used on farm equipment, tractors, earthmovers and other heavy duty construction equipment.

Positive Sensitive Damping

Positive Sensitive Damping

A damping shock absorber works with the suspension system of your vehicle to absorb unwanted vibrations and keep the ride smooth and comfortable.

However, many people don’t realize that there is a difference between a regular shock absorber and a positive sensitive one. A regular shock absorber has a plunger inside that is pushed down when you hit a bump in the road.

This causes the piston to compress a fluid inside the absorber. The pressure from the compressed fluid then pushes the plunger back up and it extends the piston.

This process repeats itself over and over and the result is a smooth and comfortable ride. But, a regular shock absorber cannot damp out the vibrations caused by certain types of road conditions.

For example, if you have a lot of loose gravel on the road, the pressure from the gravel hitting the underside of your vehicle will cause the shock absorber to work overtime and extend the piston all the way back up. This creates an uncomfortable jolting effect and makes driving very difficult.

Acceleration Sensitive Damping

Acceleration sensitive damping shock absorbers are a feature on many new vehicles. They are designed to provide a smoother ride and better handling while maintaining an optimal level of comfort.

They work by sensing when the vehicle is being driven hard and then automatically increase the amount of damping provided by the shock absorbers. This allows for a much more comfortable ride with less harshness.

This feature is especially important for drivers who frequently drive their vehicle hard on rough roads. It also helps maintain a more comfortable ride for passengers. These types of shock absorbers are now standard equipment on most new vehicles.

They are very cost effective and easy to install.



A coilover shock absorber is a device that is attached between the spring and the shock body of a suspension system. Coilovers are used to change the characteristics of a suspension system without having to rebuild or replace any of the parts.

Coilovers are used when the vehicle has been modified with performance enhancing components. Coilovers are very useful when the vehicle is being driven on rough roads or when driving over large bumps.

When the coilovers are compressed, they create an oil film between the piston and the rod. This oil film reduces the amount of friction between these two parts. As a result, the engine does not have to work as hard to overcome the resistance created by the bump.

This allows the engine to be working on other things instead of overcoming the resistance caused by the bump. This means that the engine can be working at peak efficiency which results in better gas mileage.

Monotube Shock Absorber

Monotube Shock Absorber

Mono-tube shock absorbers are the same basic design as dual-tube shock absorbers, except that there is only one piston.

This makes them cheaper to produce than a dual-tube unit, but it also means that they cannot react as quickly to changes in road conditions as a dual-tube unit. Therefore, they are not recommended for heavy use, such as off-roading or when driving on rough roads.

They are, however, very effective on smooth, hard surfaces and can be a good choice for a vehicle that will be driven on regular roads.  

They are a cost-effective alternative to a dual-tube unit and, because of this, you may see them on more vehicles in the aftermarket than you would expect.


What to do if car shock absorbers are making noise?

The sound is caused by the shock absorbers and the springs rubbing against each other. These parts should be greased regularly to prevent this from happening.

Is the shock absorber a part of the suspension?

The shock absorber is a part of the suspension.

Does the shock absorber control the height of the vehicle?

Yes, the height of the vehicle can be controlled by the shock absorber. But, the height of the vehicle can also be controlled by the operator. If the operator decides to drive too high, the shock absorbers will not be able to keep the vehicle level. 


There are many kinds of shock absorbers that are used to absorb the shocks caused by driving on uneven roads.

Shock absorbers are a very important part of the car because they reduce the amount of shocks that are transmitted to the passengers in the car.

Without shock absorbers, every bump in the road will be felt by the passengers in the car.Good shock absorbers should be made of rubber and there are many different types of them.

Each type of shock absorber has its own properties and each type of shock absorber is suitable for a particular type of vehicle.