What Is a Strut?

People talking about vehicle suspensions often refer to “shocks and struts.” Hearing this, you may have wondered just what a strut is, whether it’s the same as a shock, and whether you need to worry about your car’s or truck’s struts.

The first thing to understand about a strut is that it’s one component of a vehicle’s suspension — the system of parts that connects the wheels to the rest of the vehicle. The three major functions of any vehicle’s suspension are to:

  • Support the vehicle

  • Absorb impacts from bumps, potholes, and other road irregularities

  • Allow the vehicle to turn in response to the driver’s inputs. (The steering system can be considered part of the suspension, or its own system, but either way the suspension has to allow for movement of the wheels as the vehicle turns).

It turns out that unlike most other components of the suspension, the strut is usually involved in all three of these functions.

What's in a strut

A complete strut assembly is a combination of two main parts: a spring and a shock absorber. (Sometimes the term strut refers to the shock absorber portion only, but other times the term is used to denote the entire assembly including the spring). The spring, which is almost always a coil spring (in other words, one shaped like a spiral), supports the weight of the vehicle and absorbs large bumps. The shock absorber, which is fitted either above, below, or right down the middle of the coil spring, also supports some or all of the vehicle’s weight but its main function is the same as that of any shock absorber, namely to dampen vibrations. (Despite its name, a shock absorber doesn’t absorb shock directly — that’s the job of the spring — rather, it stops the vehicle from bouncing up and down after a bump). Because of its weight-bearing design, a strut has to be much stronger than a normal shock absorber.

Do all vehicles have struts?

Not all cars and trucks have struts; many suspension designs use separate springs and shock absorbers, with the shocks supporting no weight. Also, some cars use struts only on one pair of wheels, usually the fronts, while the other pair employs a different design using separate springs and shocks. When a car has struts on the front wheels only they are usually MacPherson struts, which are struts that are also considered part of the steering system because the wheels pivot around them.

Why do some vehicles use struts while others have separate springs and shocks? The specifics are complicated but for the most part it comes down to a trade-off between simplicity and initial cost (advantage: struts) and handling and performance (advantage: certain suspension designs without struts ... usually). But there are exceptions to these patterns; for example, most sports cars employ what’s called a “double wishbone” suspension, which uses shock absorbers rather than struts, but the Porsche 911, which is arguably the quintessential sports car, uses struts.

How to maintain your struts

What else does a vehicle owner need to know about struts? Not too much. Whether your car has struts or shock absorbers you’ll want to have them inspected periodically for leaks or other damage. One difference is that when they do wear out, struts are more expensive to replace, but there’s nothing a driver can do about that. Regardless of what suspension system your car has, be sure to have it inspected regularly — every oil change or alignment, or every 5,000 miles or so is fine.


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Recent Strut Assembly Replacement reviews

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Clarissa

27 years of experience
234 reviews
Clarissa
27 years of experience
Infiniti EX35 V6-3.5L - Strut Assembly Replacement (Front) - Wynnewood, Pennsylvania
Clarissa did a great job on my Infiniti front suspension! My Infiniti now handles and absorbs bumps like it should again! Clarissa took her time to do it right and consult with me, and also looked over the rest of the suspension, brakes, wheels and tires, etc to discuss any other necessary work. Would definitely recommend Clarissa!
Nissan Altima - Strut Assembly Replacement (Front) - Blue Bell, Pennsylvania
Terrific job - again. I’ve used Clarissa for some bigger projects - struts, new brakes, etc. Very professional, very personable and explains the process thoroughly.

Chuck

10 years of experience
347 reviews
Chuck
10 years of experience
Toyota Highlander V6-3.5L - Strut Assembly Replacement (Front) - Rowlett, Texas
Chuck was great! We talked via phone to discuss the available options to repair my Highlander. He worked with me to schedule a time that was convenient for me, and he arrived early for the appointment. He walked me through some of the other issues that exist on my 2008 Highlander which has 223k miles. His feedback on my car was clear and easy to understand.

Jonathan

35 years of experience
483 reviews
Jonathan
35 years of experience
Jeep Grand Cherokee V6-3.7L - Strut Assembly Replacement (Front) - Palm Harbor, Florida
Johnathan was right on time . He replaced both front struts on my Jeep with no problems.. He test drove it than I did. No more thumping all fixed. Johnathan was very courteous and professional. I will always ask for him when we have car problems.

Sebastian

5 years of experience
110 reviews
Sebastian
5 years of experience
BMW X3 L6-3.0L Turbo - Strut Assembly Replacement (Front) - North Palm Beach, Florida
Sebastian was professional, knowledgeable, and gave me great advice on my vehicle! After he finished, he did a total inspection and went over the work he completed on my vehicle.

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