Struts 101 Table of Contents

Introduction to Automotive Struts

Struts are an essential component of a vehicle's suspension system, playing an important role in ensuring a smooth and stable ride. Serving as a structural component, struts not only support the weight of the vehicle but also absorb shocks from the road, providing both comfort and control. For vehicle owners, car enthusiasts, and racers alike, understanding the function and maintenance of struts is integral to maximizing vehicle performance and safety.

Key Takeaways:

  • Struts support vehicle weight and absorb road shocks.
  • They play a significant role in comfort and handling.
  • Regular maintenance of struts is necessary for vehicle safety and performance.

What Are Struts?

Struts are vital components of a vehicle's suspension system, commonly found in the front end of most front-wheel-drive vehicles. They integrate several functions into a single, compact assembly. Essentially, a strut combines a shock absorber with a coil spring, providing structural support to the suspension.

Key Points about Struts:

  • Combination of Functions: A strut integrates a shock absorber and a coil spring.
  • Primary Roles: Provides structural support, maintains vehicle alignment, and absorbs road impacts.
  • Impact on Handling: Plays a critical role in steering and handling by keeping the tires aligned.

History of Struts

The evolution of struts in automotive engineering traces back to the mid-20th century when advancements in vehicle design necessitated more compact and efficient suspension solutions. Traditionally, vehicles used separate coil springs and shock absorbers. However, as front-wheel-drive vehicles became more popular, the need for a more integrated suspension system emerged. Enter the MacPherson strut, invented by Earle S. MacPherson in the 1940s.

Key Historical Facts:

  • Early Designs: Vehicles originally used separate coil springs and shock absorbers.
  • MacPherson Strut: Revolutionized vehicle suspension systems by combining components.
  • Benefits: Greater space efficiency, improved handling, and easier vehicle assembly.

Importance in Vehicle Suspension

Struts hold a pivotal position in the architecture of vehicle suspension systems. They serve as the backbone of the suspension, providing structural integrity while simultaneously absorbing shocks and vibrations from the road. This dual function is crucial for maintaining vehicle stability and ensuring a smooth ride.

Key Functions of Struts in Suspension:

  • Shock Absorption: Manages road shocks and ensures ride comfort.
  • Weight Distribution: Supports the vehicle’s weight and helps in reducing body roll.
  • Alignment Control: Keeps tires in optimal contact with the road, improving traction and safety.

Types of Struts

MacPherson Struts

MacPherson struts are among the most widely used suspension components in modern automobiles, particularly in front-wheel-drive vehicles. Named after their inventor, Earle S. MacPherson, these struts offer a compact and efficient design that combines a shock absorber and coil spring into one assembly.

Key Features of MacPherson Struts:

  • Compact Design: Combines shock and spring into a single unit.
  • Popular Use: Common in front-wheel-drive vehicles.
  • Advantages: Reduced weight, improved handling, easier maintenance.

Double Wishbone Struts

Double wishbone struts, also known as double A-arm suspension, offer enhanced performance characteristics compared to other strut types. These struts feature two control arms that resemble wishbones, providing a more complex suspension geometry.

Key Features of Double Wishbone Struts:

  • Complex Suspension Geometry: Provides better control over wheel movement.
  • Handling and Stability: Improves steering precision and reduces body roll.
  • Ideal for Performance: Common in luxury and performance vehicles.

Coilover Struts

Coilover struts represent a versatile and adjustable suspension option, combining a coil spring encircling a shock absorber within a single unit. Known for their adaptability, coilovers allow drivers to fine-tune their vehicle's ride height and damping characteristics.

Key Features of Coilover Struts:

  • Adjustable Design: Allows for customization of ride height and damping.
  • Versatility: Suitable for track racing and everyday use.
  • Performance Benefits: Provides superior handling and cornering stability.

How Struts Work

Components of Struts

Struts are composed of several key components that work together to provide structural support and shock absorption for a vehicle. The primary elements include the coil spring, shock absorber, and strut housing.

Key Strut Components:

  • Coil Spring: Supports vehicle weight and absorbs large road impacts.
  • Shock Absorber: Controls spring movement and smooths out vibrations.
  • Strut Housing: Provides structural integrity and connects components to the vehicle.

Mechanics of Strut Function

The mechanics of strut function lie in their ability to dampen road shocks while maintaining vehicle stability and control. When a vehicle encounters a bump, the coil spring compresses, absorbing the impact and reducing the shock transferred to the chassis.

How Struts Function:

  • Absorbs Impact: The coil spring compresses to absorb bumps.
  • Dampens Oscillation: The shock absorber within the strut controls spring motion.
  • Steering Role: The upper strut mount allows the strut to pivot for steering control.

Read More: Strut Mounts

Struts vs. Shock Absorbers

While struts and shock absorbers both serve to dampen road shocks and enhance ride quality, they differ significantly in design and function. Struts are structural components of the suspension system, integrating a coil spring and a shock absorber into a single unit.

Differences Between Struts and Shocks:

  • Struts: Support vehicle weight, maintain alignment, and provide damping.
  • Shocks: Control oscillations but do not support vehicle weight or affect alignment.
  • Application: Struts are more complex and impact steering dynamics, while shocks are used in systems with separate springs.

Read More: Are Shocks and Struts the Same Thing?

Common Strut Issues

Signs of Worn Struts

Recognizing the signs of worn struts is crucial for maintaining vehicle safety and performance. One of the most evident indicators is a rough and bumpy ride, as worn struts fail to absorb shocks effectively.

Common Signs of Worn Struts:

  • Bumpy Ride: Fails to absorb road shocks, leading to discomfort.
  • Excessive Bouncing: Occurs after hitting a bump or pothole.
  • Uneven Tire Wear: Misalignment caused by worn struts affects tire wear.

Common Strut Failures

Common strut failures can significantly impact a vehicle's handling, safety, and ride comfort. One prevalent issue is leaking hydraulic fluid, which occurs when the seals inside the strut deteriorate.

Frequent Strut Failures:

  • Leaking Hydraulic Fluid: Reduces damping ability and increases bounce.
  • Broken Coil Spring: Causes sagging and affects ride height.
  • Worn Strut Mounts: Leads to steering problems and clunking noises.

Read More: Electronic Struts vs Passive Struts

Maintenance Tips

Proper maintenance of struts is essential to extend their lifespan and ensure optimal vehicle performance. Regularly inspecting struts for signs of wear or damage, such as leaks, rust, or unusual noises, can help identify issues early.

Strut Maintenance Checklist:

  • Regular Inspections: Check for leaks, rust, or noises.
  • Mileage-Based Replacement: Replace every 50,000 miles or as needed.
  • Balanced Replacement: Replace struts in pairs (front or rear) for even handling.

Strut Replacement and Upgrades

When to Replace Struts

Determining the right time to replace struts is crucial for maintaining vehicle safety and performance. Persistent symptoms such as a bumpy ride, unusual noises, or excessive bouncing after hitting a bump are clear indicators.

Signs That Struts Need Replacing:

  • Unstable Ride: Difficulty maintaining straight-line stability.
  • Increased Stopping Distance: Struts affect braking efficiency.
  • Leaking Fluid: Visible leaks indicate seal failure.

Choosing the Right Struts

Selecting the right struts for your vehicle is essential for maintaining optimal performance and safety. Start by considering your vehicle's make and model, as manufacturers often recommend specific strut types tailored to each vehicle.

Factors to Consider When Choosing Struts:

  • Vehicle Make and Model: Ensure compatibility with manufacturer specifications.
  • Driving Conditions: Heavy-duty struts for rough roads; standard for everyday use.
  • Quality and Brand: Opt for reputable brands known for performance and reliability.

Upgrading to Performance Struts

Upgrading to performance struts can significantly enhance your vehicle's handling, stability, and overall driving experience. Performance struts are designed to provide better damping characteristics and support, making them ideal for high-speed driving and aggressive cornering.

Benefits of Performance Strut Upgrades:

  • Better Handling: Provides improved cornering stability and control.
  • Customizable Settings: Adjust ride height and stiffness for various driving conditions.
  • Increased Durability: Engineered to withstand more demanding road conditions.

By following this comprehensive guide, you can understand the importance of struts in your vehicle's suspension system, recognize common strut issues, and make informed decisions when it's time to replace or upgrade your struts.