Your vehicle’s suspension system keeps you and your passengers safe, comfortable, and stable. At the heart of this system are two key components: shocks and struts. These are designed to absorb the bumps and jolts of the road, keeping your tires in contact with the ground and preventing your vehicle from bouncing or swaying excessively.
Shocks and struts are critical to your vehicle’s handling and safety, and it’s essential to understand the differences between them to make informed decisions about your suspension system. In this blog post, we’ll explore the differences between shocks and struts and provide tips for choosing the right components for your vehicle.
Shocks vs. Struts
The most important thing to understand about shocks and struts is that they serve a similar purpose but are different in design, construction, and function.
Shocks in the Front
Shocks are a single component designed to absorb the energy of bumps on the road surface. Essentially, they are hydraulic cylinders filled with fluid and have a piston inside that moves up and down in response to bumps in the road. As the piston moves, it compresses the liquid, which absorbs the impact’s shock and reduces the bounce or sways that your vehicle experiences.
Struts in the Back
Struts, conversely, are more complex and have additional components beyond just the shock absorber. In addition to the hydraulic cylinder and piston, struts have a coil spring and an upper chamber that houses the upper control arm and other weight-bearing components. The coil spring helps to support the vehicle’s weight, while the upper chamber and control arms help to provide additional stability and control.
Differences Between Shocks and Struts
While shocks and struts serve similar purposes, they are different in design and function. In this section, we’ll explore these differences in more detail.
The critical difference between shocks and struts is that shocks are typically used on vehicles with a separate spring assembly. In contrast, struts are used on vehicles with a coil spring integrated into the suspension system.
Shock Absorbers
Shocks are essentially hydraulic cylinders filled with fluid and have a piston inside that moves up and down in response to bumps in the road. As the piston moves, it compresses the fluid, which absorbs the impact’s shock and reduces the bounce or sways your vehicle experiences. Shocks are typically mounted separately from the springs and other suspension components.
Coil Springs
Coil springs are used to support the weight of the vehicle and maintain the proper ride height. They are often used in conjunction with shock absorbers but also with struts.
Upper Control Arm
The upper control arm is a critical suspension system component that connects the wheel hub assembly to the chassis. It helps to control the motion of the wheel and maintain proper alignment. In vehicles with struts, the upper control arm is usually housed in the upper chamber of the strut assembly.
Hydraulic Fluid
Both shocks and struts use hydraulic fluid to absorb the shock of bumps and jolts in the road. The fluid is usually a specialized oil resistant to foaming and temperature changes, which can affect its ability to perform.
Handling Characteristics
Because of their different designs, shocks, and struts can have slightly different handling characteristics. Vehicles with struts tend to have better handling and stability, especially in cornering situations. Shocks are more commonly used in off-road cars and trucks, where they can handle rough terrain more effectively.
Road Surface
Another difference between shocks and struts is how they handle different types of road surfaces. Struts are better suited for smooth roads, while shocks are better for rough terrain. This is because the additional weight-bearing components of struts can make them less effective at absorbing significant impacts, while shocks are better at handling larger bumps and jolts.
Spot Worn Shocks and Struts On Time
Common issues with strut assemblies include compression cycle issues, fluid leaks, and problems with weight-bearing components. These issues can occur due to wear and tear over time and damage caused by potholes, rough roads, and accidents.
A worn or damaged strut can cause your vehicle to bounce excessively, leading to a rough ride and poor handling. A leaky strut can also cause fluid to leak onto other suspension components, leading to further damage and potential safety issues.
Like any other mechanical component, shocks and struts wear out over time due to regular use. The hydraulic fluid inside the shocks and struts can become contaminated or lose its viscosity, which can cause the shocks to become less effective at absorbing bumps and jolts in the road. The internal components of the shocks and struts can also wear out or become damaged, which can compromise their performance.
Several telltale signs indicate that your shocks or struts may be worn and need replacement. These include:
- Uneven tire wear: Worn shocks and struts can cause your tires to wear unevenly, leading to shorter tire life and reduced handling performance.
- Issues with the upper control arm: If your shocks or struts are worn, it can cause the upper control arm to move more than it should, which can lead to alignment issues and other handling problems.
- Fluid leak: If you notice a fluid leak near your shocks or struts, it could be a sign that the seals have failed and the internal components are compromised.
- Excessive bouncing: If your vehicle bounces excessively after hitting a bump or going over speed bumps, it could be a sign that your shocks or struts are worn and no longer provide adequate damping.
Strut Issues Are a Safety Hazard
The deterioration of shocks and struts can affect a vehicle’s stability and safety, resulting in a less smooth ride and reduced handling ability. This can be especially dangerous on uneven roads, where the vehicle may become unstable and difficult to manage.
Worn shocks and struts can cause your tires to wear unevenly, affecting your vehicle’s ability to grip the road and handle turns effectively. This can increase your stopping distance and make it more difficult to avoid accidents.
Can You Have a Shock and A Strut on the Same Vehicle?
Depending on the manufacturer’s design, some vehicles may have shocks and struts. Shocks and struts perform the same primary function of dampening the vehicle’s suspension, but the design and location of the components can vary.
Combining shocks and struts on the exact vehicle can impact handling and stability. This is because shocks and struts have different designs and may not work together seamlessly. Following the manufacturer’s recommendations for your vehicle is vital to ensure optimal performance and safety.
I’d recommend sticking with the suspension setup recommended by the vehicle manufacturer. They design and test their vehicles with specific suspension components for optimal performance, handling, and safety.
Final Thoughts
Proper maintenance of a vehicle’s suspension system requires following the manufacturer’s guidelines and installing high-quality, branded shocks and struts.
By staying on top of maintenance and addressing any issues promptly, you can help ensure a smooth, safe, and comfortable ride for you and your passengers. Have your vehicle inspected by a qualified mechanic if you notice any issues with your suspension or ride quality.
Those interested in learning more about the better brand-name shocks available on the market and the differences between shock absorber types might want to read my take on Mevotech vs. Moog suspension parts.