What's The Difference Between A Shock And A Strut?

Shocks and struts are the most common components replaced during a typical suspension repair. They're also commonly confused with one another, thanks in large part to their similar design. The following is a quick guide to help do-it-yourselfers tell the difference between their shocks and struts:

The Basics on Shocks

A shock absorber, or "shock" for short, is a long two-piece tube that contains a series of valves filled with oil. As a vehicle rolls over bumps and imperfections in the road surface, the energy of those bumps are absorbed by the shock absorber. The oil within the shock absorber flows through the various valves at specific rates, softening and smoothing out the otherwise harsh suspension movement.

As shocks age, they tend to leak oil. A loss of oil effectively renders the shocks useless at absorbing suspension impacts until they're replaced. Replacing the shocks is a relatively straightforward task - all you have to do is remove the shock absorber and attach a new one in its place.

However, some vehicles may require you to first compress and remove the springs, a task that should only be performed with a reliable spring compressor.

What About Struts?

Struts look a lot like shocks and they even perform the same tasks as shocks, but the overall design and intent is different. For instance, the coil spring is integral to the strut assembly instead of being completely separate from the shock absorber.

Unlike shocks, struts are designed as an integral part of the vehicle. In other words:

• If you were to remove the shocks, the car would still be held off the ground by its springs. You wouldn't have much of a pleasant ride, though.
• If you were to remove the struts, however, the car would drop to the ground and become practically immobile. The only thing that would keep the wheels attached to the car, aside from the axles, would be the lower control arms.

The typical strut is designed to be replaced in individual pieces or as a complete unit otherwise known as a loaded strut. Replacing one of these on your own is much easier, since you won't have to compress the coil springs or focus on strut alignment. Other types of struts feature replaceable cartridges that allow you to remove the shock portion of the strut without having to remove the entire unit from the vehicle.

Coilover shocks look very similar to struts, especially when viewing the upper portion of the shock. However, coilover shocks have a different mounting design and they're not an integral part of the vehicle's suspension. To learn more, contact a company like Affordable Automotive Service Center with any questions you have.