DIY

Shocks vs. Struts: What You Need to Know

Reading Time: 7 minutes

Have you ever owned a car with such a bumpy ride that every road imperfection was sent straight to the seat of your pants? Perhaps, the rough ride was accompanied by a symphony of clunking and banging noises, as well?

If so, you may have a set of bad shocks or struts on your hands. When these suspension components wear out, they can make your car extremely uncomfortable—not to mention unsafe.

To properly deal with any issues you may be experiencing with your suspension system, you need to understand what the shock and strut mount is, why you need it, and how to replace it.

What are Shocks and Struts?

The shock and strut mount is a vital component of the suspension. It insulates tire noise and vibrations from the cabin. It is also responsible for creating a smooth steering movement and response through the bearing working as a steering pivot.

Shocks and struts serve the same general purpose: dampening oscillations from your car’s springs. Without the shocks and struts, after hitting a bump, the springs would be uncontrolled and your car would continue to bounce.

Most shocks and struts contain hydraulic fluid. When the car travels over a bump and the spring moves up and down, the fluid acts against a piston inside the strut, creating the resistance needed to limit spring oscillations.

There is a spring, as well as either a shock or a strut, at each corner of your vehicle.

What’s the Difference Between Shocks and Struts?

Are shocks and struts the same thing? The short answer—not really.

Although shocks and struts both serve the same primary purpose, they’re not the same thing. The main difference is that each strut is integrated into an assembly with one of the suspension coil springs. Shocks, on the other hand, are stand-alone components.

Also, because of their design, struts act as a structural part of the suspension—shocks do not. Furthermore, front strut assemblies often contain a bearing that serves as a pivot point for the steering knuckle. 

Shock absorbers and struts are different parts of a car’s suspension system. Despite the differences between them, the mounts are similar and the terms are often intertwined.

Struts

Shocks

What are the Parts of a Strut Assembly?

The strut mount is only one component of the strut assembly. Most include the strut, bump stop or boot, spring seat, spring, and mount. Some of them also include mount bearings and a spring isolator.

While various cars have different formats, you can expect the majority of them to include a strut body or insert. Older cars utilize the insert more than modern vehicles do. There’s also the bump stop or boot. This isn’t always required depending on the strut’s protected position.

Why Do Shocks and Struts Wear Out?

Just think about it: shocks and struts absorb violent spring oscillations for tens of thousands of miles. If that were your job, you’d eventually wear out, too. That’s why shocks and struts are not expected to last the lifetime of your car. 

Much like brakes and tires, these suspension components are considered “wear items” that will eventually need to be replaced.

What Happens When Strut Mounts Wear Out?

Strut mounts endure heavy vibration and continual shock. As with any rubber on metal bonded part; it is going to wear down. | Pictured: Used parts of a suspension system

Worn strut mounts or bearing plates affect vehicle handling and safety adversely. These are vital aspects to the vehicle suspension and shouldn’t be ignored. Worn out strut mounts and bearing plates change breaking distances, steering capability, and tracking.

For these reasons, it’s not safe to drive a vehicle with defective strut mount bearings. Furthermore, ignoring the problem only leads to further damage to the suspension. This isn’t just unsafe but leads to additional costs for repair.

Aside from the safety concerns, worn out strut mounts create a lot of noise. This can become annoying and disruptive to your daily drive.

Bad Strut and Shock Symptoms

Think you have bad shocks or struts? If you have one or more of the following symptoms, you might be right.

Rough ride

An extremely bumpy ride is the number one symptom associated with worn shocks or struts.

Strange noises

Shocks and struts that are worn or damaged may make a clunking noise. The sound is most noticeable when traveling over bumps.

Abnormal tire wear

Worn shocks and struts cannot properly control spring oscillations. As a result, your car’s wheel and tire assembly bounce up and down more than normal. Eventually, the issue can lead to tire cupping (a series of high and low spots on the tread).

Improper wheel alignment

Since struts act as a structural portion of the suspension, if they’re damaged, they can throw off your car’s wheel alignment. 

Fluid leaks

In many cases, an accumulation of hydraulic fluid will develop on the exterior of a blown shock or strut.

Of course, there are a lot of other issues (besides shocks and struts) that can cause the problems listed above. Be sure to get a professional diagnosis before jumping to conclusions.

Among these symptoms, there are also some visual indications you can watch for. Whether you look at the components yourself or you get a professional mechanic to inspect them, look for the following signs:

When to Replace Shocks and Struts

As a general rule of thumb, shocks and struts should be replaced every 50,000 to 100,000 miles. That figure, however, is just an estimate. Real-world results will depend on factors such as the type of driving you do, as well as the kinds of roads you travel on.

Strut mount bearings often last for the life of a vehicle. Still, high loads, extreme wear, and external influences lead to premature failure. This might include temperature fluctuations, humidity, salt, and frost.

If you need to replace your coil springs or struts due to wear or age, then you should also swap out the mounts. To remove the strut and spring assembly, you need to take out the mount anyway, so it’s more cost effective to do this at the same time.

It’s not uncommon to experience unusually stiff or loose steering when the strut mount is failing.

What Happens if You Keep Driving With Bad Shocks or Struts?

A set of bad shocks or struts can cause more than just a bumpy ride. When these suspension components wear, they can also affect your car’s handling and braking ability, leading to reduced vehicle safety.

In other words: If you’ve got a set of bad shocks or struts, it’s best to address the problem sooner rather than later.

Anytime you replace strut and shock mounts, you want to do it in pairs – left and right because these endure the same road conditions and number of miles.

Shock or Strut Replacement Cost

Typically, shocks and struts are replaced in pairs, rather than individually. Why? Because if one is worn out, the other is almost certain to follow suit.

Shocks usually cost less to replace than struts. Expect to pay between $500 and $1000 [M1] for a pair of shocks; between $1000 and $2000 for a pair of struts. Naturally, if you have a premium or high-performance car, the cost may be higher.

How to Replace Shocks and Struts

If you plan to tackle the repair yourself, you will need some equipment. Make sure you have these tools on hand.

Replacing your shock and strut mount is a difficult job, but it can be done yourself. Prepare your tools and your workspace before following these steps.

Step 1: Lift your vehicle with a floor jack. Secure the frame with your jack stands. Make sure you only work on one wheel at a time. Loosen the nuts on the wheel with your impact gun. Remove the wheel and set it nearby.

using a floor jack to lift the car to gain access to the strut mount
To replace your car’s shock and strut mount, lift your vehicle using a floor jack and secure the frame with jack stands. Make sure to only work on one wheel at a time.

Step 2: Locate the mount. It should be connected to the strut tower. It is held in place with nuts or bolts that must be removed with a socket and ratchet. Put the bolts in a safe spot while working.

removing shock and strut mount nuts and bolts using automatic tool
The mount should be connected to the strut tower held in place with nuts or bolts that must be removed with a socket and ratchet.

Step 3: Remove the strut assembly from your vehicle and compress the spring. Then, take off the shock and strut mount. Replace it with the new one. Ensure you line up the holes before tightening down the nut with a torque wrench. You might want to utilize a vice to keep your mount steady during tightening.

the shock and strut mount and assembly removed to be replaced with a new one
Replace the shock and strut mount with the new one. Ensure you line up the holes before tightening down the nut with a torque wrench.

Step 4: Put your wheel back in place and tighten the nuts. Turn the steering wheel to check for proper installation. There shouldn’t be any binding or noises if it’s done correctly.

Step 5: Repeat steps 1-4 on the other side of your vehicle.

Step 6: Lower the vehicle and make sure it sits at equal heights on both sides.

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Author

Brian Jones

ASE Certified Master Tech and Parts Specialist

Brian Jones spent more than 20 years working as an ASE Certified Master Tech and Parts Specialist at multiple dealerships. Currently, he lives with his wife and children in a suburb of Dallas, TX. He spends his time dreaming about pickup trucks, muscle cars, Jeeps and anything related to motorsports. He works with numerous dealerships around the country as a consultant. In his spare time, Brian likes to visit new places and hopes to travel the world.

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