Ultimate Shock Absorbers Buying Guide

Shock absorbers are a crucial component of your suspension system. As the name suggests, they absorb shock.

But there's more to it than that. How they work and if they're working correctly has a direct impact on the rest of your car.

To help our customers understand how shock absorbers work and how to choose the right replacements online, we've created this comprehensive guide that covers everything.

We’ll cover:

• What are shock absorbers?
• How do shock absorbers work?
• Why do they matter?
• How to tell if your shock absorbers need changing
• The types of shock absorbers available online
• The best shock absorber brands and options
• How to choose the right shock absorbers
• Frequently asked questions about shock absorber parts

What Are Shock Absorbers?

Shock absorbers are the hydraulic or gas-filled components controlling how your car responds to bumps, potholes, and uneven road surfaces. It's more common for modern cars to have hydraulic shock absorbers.

But more than that, they keep the four wheels of your vehicle on the ground. It's an incorrect assumption that shock absorbers support the weight of your car; that's actually the much smaller and less obvious wheel bearings. Shock absorbers do, however, keep the bottom of the tire surface in contact with the ground.

Part of the shock absorbers are springs and struts that become a cushion between the axles and the body of the car, reducing shocks, wheel oscillation, and vibrations when you go over uneven road surfaces.

They also help your car absorb braking forces and affect how you maneuver your car.

The shock absorbers are mounted between the car chassis and the wheels. They'll either be alongside the spring or inside it, which depends on the specific vehicle suspension design of your car. Both sides of the front and rear axes have shock absorbers.

A standard hydraulic shock absorber (twin-tube or monotube) will have:

• A piston rod
• A piston
• A cylinder (pressure tube)
• A base valve (only in twin-tube designs)
• Hydraulic fluid
• A gas chamber (only in gas-pressurized shocks)

How Do Shock Absorbers Work?

As your car travels over bumpy surfaces, the wheel naturally moves upward, and a piston rod pushes into the cylinder. That spring pushes fluid through the small valves in the piston and the base valve. 

Hydraulic resistance develops to slow the piston's movement, and the energy is dissipated as heat within the fluid. That action is called the compression stroke, and it compresses so that it doesn't continue to bounce up and down, as you can imagine a spring would, until friction and air resistance dissipate the energy. It's technically incorrect to say that shock absorbers absorb the shock.

They actually dampen the motions created by uneven surfaces by converting the kinetic energy of the spring as it moves up and down into thermal energy.

The rebound stroke, or the extension phase, happens as the spring tries to return to its original shape. Fluid moves through rebound valves within the piston, and the resistance is more often than not greater than in the compression stroke.

This two-stage damping process generates smooth wheel motion and prevents excessive oscillations.

Some cars have different shock absorbers. For example, on pickup trucks, shock absorbers are built for the heavier load. They will look a lot bigger, but their function is still the same as standard cars. The only difference is that they can withstand more load.

Why Do They Matter?

Without shock absorbers, you wouldn't have the safe, comfortable driving experience that you do.

More than that, shock absorbers keep the contact between the car and the road. The springs would almost endlessly oscillate and lift the tires off the road with every bump without the shock absorbers. Effectively, the tires would spend every second of your driving in the air.

There's also constant micro movement control from the shock absorbers through every brake and acceleration. They would pitch forward during braking, or they would squat backward during acceleration. And cornering would be worse, with the car rolling excessively or rolling completely if not for the movement control of the shock absorber.

And with the roll and movement control, there's a better transfer of weight distribution. And as we said, it's true that shock absorbers don't take the weight of the car, but the suspension geometry staying consistent keeps the weight consistent.

Then there's the mechanical fatigue on the rest of the components. The tires would wear out, and the steering rack and mounts wouldn't cope.

How to Tell if Your Shock Absorbers Need Changing

Here are the signs your shock absorbers need changing:

• Excessive bouncing after going over a bump in the road
• Uneven tire wear
• Increased braking distances
• Vibrations or rattling in the steering wheel
• Hydraulic fluid leaking
• A knocking noise when driving over rough surfaces

Your shock absorbers need checking with every service or every 80,000 km. Depending on the type of shock absorber and driving habits, they should last between 80,000 and 160,000 km or every 5 to 10 years.

Because they work in pairs, you should replace them in pairs. The front and the rear together keep the suspension balanced.

If you notice that it's less comfortable when you're driving or that there's fluid close to the tires, for example, take your car to be checked.

When doing a visual inspection, check for dents or heavy corrosion or rusting. Most modern designs have a protective coating, so you shouldn't see rusting or corrosion unless your car is really old. You might notice dents or cracks, especially if you've gone over a speed bump at force, for example. Or, if there's an oil leak, you'll either see the oil on the shock absorber or on the floor around it.

Although you can see the shock absorbers by looking at each corner of the car, near the tires, we would recommend taking it to a professional mechanic.

The Types of Shock Absorbers Available Online

Conventional telescopic shock absorbers

Conventional, also called stand-alone telescopic shock absorbers, are the simplest design. You don't really find them on the front suspension of modern cars, but they are sometimes on the rear. They're more common on older makes and models.

They're designed with an outer tube that holds hydraulic oil and an inner tube where the piston moves up and down. Inside the shock absorbers are small valves that regulate the speed of oil flow between the chambers. They're compact, lightweight, and suitable for the average driver and driving conditions.

The issue is that conventional shocks don't carry any structural load. They're only designed to dampen. Conventional springs should always be mounted with a coil or leaf spring for stability.

Best for: Small passenger cars and light commercial vehicles with separate springs and shocks.

Strut-type shock absorbers

A strut-type shock absorber combines the damper and structural suspension element. They always come with the shock absorber and spring in one unit.

The upper part of the strut connects to the vehicle body using the bearing mount. The lower end connects to the steering knuckle. That design saves space and weight and makes this a lightweight, affordable, and effective absorber.

With this type of shock absorber, the struts carry lateral loads, and they must be stronger than standard shocks. Within the absorber is the same piston and hydraulic fluid as in conventional designs, but the casing and rod are thicker to resist bending.

Best for: Front-wheel-drive cars and most modern sedans.

Spring seat shocks

Spring-seat shocks combine the telescopic and strut-type designs. There's a spring seat welded onto the shock body that supports the coil spring. But unlike strut absorbers, they don’t bear the same structural loads.

For us, it's the perfect hybrid setup that simplifies assembly and provides more consistent ride comfort. They're also easier to replace because the upper mount remains separate.

Best for: Rear suspensions of hatchbacks, small SUVs, and light vans.

Twin-Tube Shock Absorbers

Twin-tube shocks are the most common design in modern cars. They have two concentric cylinders. One is an inner "working" tube where the piston moves. The other is the outer "reserve" tube that stores excess oil and gas.

Whenever your car goes over a bump in the road, the hydraulic oil flows between the tubes and the calibrated valves. That movement controls compression and rebound forces.

Twin-tube designs provide the most comfortable and soft ride. That's why they're so popular with modern manufacturers. They're also cheaper monotube types (next section).

We will say that they're not ideal for high-performance models because the oil can foam during heavy use.

Best for: Everyday drivers who want a comfortable suspension system.

Monotube Shock Absorbers

Monotube shocks have a single pressure tube divided into two chambers. One is for hydraulic oil and one for high-pressure gas (usually nitrogen). Separating the two is a floating piston.

Monotube shocks dissipate the heat more effectively than other options. They also resist aeration and maintain consistent damping under high stress. Because the piston area is larger, monotube shocks respond faster to wheel movement and give you precise control.

They can be fixed in any orientation and often have an external reservoir for improved cooling.

Best for: Sports cars, performance vehicles, and drivers wanting sharper handling.

The Best Shock Absorber Brands and Options

At Parts Avenue, we only stock the best shock absorber brand: TMC. With TMC, you get the original equipment-level part you need at an affordable price. We know TMC provides the best types of shock absorbers.

TMC

TMC shock absorbers go beyond original equipment-level quality and source elite manufacturer-level NBR rubber seals for precision control. When you buy shock absorbers online, manufactured by TMC, you get a chrome-plated steel piston rod that's also excellent for resisting corrosion and giving the suspension system the strength it needs to keep your car stable. 

And with 5 sealing techniques providing a leak-proof design, you can expect high-tech motion dampers that adjust dynamically to any movement.

How to Choose the Right Shock Absorbers

1. Check the Fitment

On each Parts Avenue product page, you’ll find our Fitment Check Tool just below the part title. Input your car’s year, make, and model, and the system instantly confirms whether the part fits.

2. Identify the Suspension Type

You should know the suspension type suitable for your vehicle size and driving style. For example, if your car uses MacPherson struts on the front axle, you’ll need complete strut assemblies. Rear axles might use separate shocks.

3. Match Your Driving Style

Twin-tube hydraulic shocks are excellent for city or highway driving. They provide the comfort and control you need. For mountain roads or off-roading, monotube gas-charged shocks handle heat and pressure better.

Frequently Asked Questions About Shock Absorber Parts

How long do shock absorbers last?

Most shock absorbers last between 80,000 km and 100,000 km. The actual lifespan depends on your driving style and how much you drive. If you only drive to work and back on the highway, your shock absorbers will last longer.

Can I replace only one shock absorber?

We wouldn't recommend replacing only one shock absorber. You risk creating uneven loads across the suspension and wheels. If you look to buy shock absorbers through Parts Avenue, you'll notice we only sell them in pairs: either the two at the front or the two at the rear.

What’s the difference between hydraulic and gas-charged shock absorbers?

Hydraulic shocks use oil to control damping and generate a smoother ride. Gas-charged shocks have a small nitrogen charge that generates improved responses and prevents fluid foaming. They're far better for performance driving.

Are adjustable shocks worth it for daily driving?

If you enjoy fine-tuning your car's feel or occasionally drive on rough roads, yes. For most drivers, standard twin-tube or gas-charged shocks are perfectly adequate.

We have an almost endless list of the highest-quality shock absorbers in Canada. If you need any help or advice on selecting the best shock absorber for your car, send us an email at info@partsavenue.ca.

Start your search today with Parts Avenue, the most-trusted car parts provider in Canada.