Shocks vs Struts – The key differences

Depending on the type of car, it will either have shocks or struts to stabilise the ride and keep you comfortable on the road.

Many people will refer to these components interchangeably, but in actual fact, they are, and work, notably different.

Shocks vs Struts

Conventional shock absorbers do not support vehicle weight, instead, they control spring and suspension movement, according to Monroe, a leading manufacturer of these components.

Shock absorbers in layman’s terms can be likened to oil pumps. A piston is attached to the end of the piston rod and works against hydraulic fluid in the pressure tube.

As the suspension moves up and down, the fluid is forced through the orifices inside the piston, but these tiny holes let only a small amount of fluid through which in turn slows down spring and suspension movement.

All shock absorbers are “velocity-sensitive hydraulic damping devices,” meaning the amount of resistance they provide depends on the speed of the suspension and the number and size of the tiny orifices in the piston.

Therefore, the faster the suspension system moves, the more resistance the shock absorber provides, said Monroe.

Shocks’ main purposes are to reduce bounce, roll and sway, and brake dive and acceleration squat in a vehicle.

Shock absorbers

Struts, on the other hand, are a major structural part of a suspension system.

They typically comprise a strut housing to provide rigid structural support for the assembly, paired with a damping unit within the strut housing to control spring and suspension movement.

On most struts, the bottom of the body attaches to the steering knuckle, which in turn connects to a lower control arm through a lower ball joint.

Struts perform a similar job to shock absorbers and work on the same hydraulic principle, where fluid is used to control spring and suspension movements.

They have other goals, too, which are to provide structural support for the suspension and control spring, and to hold the tyre in line.

As such, struts affect ride comfort and handling as well as vehicle control, braking, steering, wheel alignment, and wear on other suspension parts.

Strut components

To find out which type of dampers your car has, you can read the owner’s manual, search the vehicle online, ask a professional, or simply look under the wheel wells yourself.

Keep in mind, your particular vehicle may have both these components, for example, shocks in the front and struts in the back.

If you think your ride may need new dampers, there are four obvious signs to look out for, including:

• Leaking fluid
• Rough and bumpy ride
• Uneven tyre tread wear
• Instability when braking or turning

If it is exhibiting one or more of these conditions, it’s recommended to visit your nearest technician to find out whether the dampers are due for a replacement.