How to tell if coil springs need replacing?

Coil springs typically need replacing when the car sits lower or unevenly, the coils show damage or rust, you hear clunks or bangs, and ride quality deteriorates or tire wear worsens.

Coil springs are a fundamental part of a vehicle’s suspension. They support the weight of the car, maintain ride height, and work with dampers to control motion. Over time, springs can fatigue, corrode, or crack, especially after pothole impacts or heavy loads. This article explains the telltale signs and how to assess whether replacement is necessary, plus what to consider when deciding on replacement options.

Visible signs and symptoms to watch for

The following list highlights common visual and performance cues that springs may be near the end of their life. Use this as a checklist to decide if a professional inspection is warranted.

• Sagging or uneven ride height on one corner or axle


• Visible cracks, breaks, deformation, or severe rust on the coils


• Coils that are touching or binding together due to deformation


• Bottoming out or harsh, jarring impacts over bumps


• Rough ride quality or unusual clunks, bangs, or squeaks when going over bumps


• Uneven tire wear or changes in alignment that aren’t explained by steering components


• Vehicle leaning excessively when loaded, such as with passengers or cargo

Not every sign confirms a spring failure on its own, but a combination of height change, damage, and handling issues strongly suggests replacement is due.

How to assess the suspension safely and effectively

Before attempting anything yourself, it’s important to understand safe procedures and the limitations of springs. The following steps help you evaluate the springs without misdiagnosis. If you’re unsure, seek a qualified technician to confirm the cause of the symptoms.

1. Park on a level surface and check ride height at each corner. Compare the gap from the wheel arch to the top of the tire with the vehicle’s factory specification or a known-good reference.


2. Visually inspect each coil for cracks, severe rust, or deformation. Look for coils that are separated or contact each other when the suspension is compressed.


3. Check for symmetrical wear. Compare both sides of the same axle to see if one side shows more sag or damage than the other.


4. Gently compress and release each corner by pressing down on the bumper or fender. Note excessive bouncing or a slow return to normal height, which can indicate worn springs or related components.


5. Inspect associated suspension components. Worn shocks or struts, damaged mounts, or broken rubber bushings can mimic or contribute to spring symptoms and should be evaluated together.

If you observe obvious damage, cracks, or persistent sagging, or if the vehicle bottoms out frequently, arrange a professional inspection. A technician can perform a more thorough assessment, including load testing and measuring ride height across the vehicle in multiple conditions.

Replacement considerations and what to expect

Should you replace both springs on an axle?

In most cases, it’s best to replace both springs on the same axle or across the same pair of wheels. Springs wear at similar rates, and replacing one spring without addressing the other can lead to uneven handling or accelerated wear on the remaining spring. If one spring has failed, inspect the companion spring for signs of fatigue as well.

OEM vs aftermarket springs

Original equipment manufacturer (OEM) springs are designed to meet the factory ride height and handling characteristics. Aftermarket springs offer various options (e.g., progressive-rate, stiffer performance springs, or load-rated springs for heavier use). The right choice depends on your goals (comfort, towing, off-road use) and the vehicle’s design. A professional can help you select springs that preserve proper alignment and ride comfort.

Other components to consider replacing simultaneously

Springs don’t wear in isolation. If you’re addressing worn springs, consider inspecting and possibly replacing related parts at the same time, such as shocks/struts, mounts, and bushings. Replacing worn shocks or struts along with springs helps restore proper damping and overall ride quality and can prevent uneven spring wear.

Preventive tips to extend spring life

While you can’t stop everyday driving wear entirely, these practices can help preserve spring integrity longer.

• Avoid carrying loads beyond the vehicle’s rated capacity and use proper distribution of cargo.


• Drive carefully over potholes and speed bumps, and try to avoid repeated hard bottoming.


• Have a professional inspect the suspension after a collision or significant impact.


• Keep up with regular vehicle inspections, especially if you notice changes in ride height or handling.

Regular inspection and timely replacement when signs appear help maintain handling, ride comfort, and tire life.

Summary

Coil springs indicate the health of your suspension through ride height, damage, noise, and ride quality. Look for sagging, cracked or corroded coils, and abnormal handling or tire wear. If in doubt, have a technician confirm whether replacement is needed. Replacing springs in pairs, considering OEM or appropriate aftermarket options, and inspecting adjacent components like shocks and mounts improves reliability and ride performance.

Conclusion

Knowing the signs of worn coil springs and understanding replacement considerations can save you from unsafe driving conditions and costly damage down the line. When in doubt, prioritize a professional diagnostic to ensure your suspension is restored to safe, optimal performance.

Does replacing your coil spring improve ride?

Coil springs also help prevent the vehicle from bottoming out when loaded or during adverse driving conditions by working to maintain optimal ride height as determined by the manufacturer. Replacing the coil springs on a vehicle can have a dramatic impact on its ride and handling.

How to test a coil spring?

To test coil springs, you can perform a visual inspection for damage, or apply controlled forces to measure deflection and load to determine their performance. For a visual inspection, look for cracks, corrosion, dents, or uneven ride height, as these are signs of a broken or weakened spring. For a more technical test, apply a known weight to compress the spring and measure how far it deflects, which indicates the spring's force-deflection characteristics.
 
This video demonstrates how to visually inspect coil springs for damage: 59sYou WrenchYouTube · Jul 31, 2021
Visual inspection

• Park and observe: Park your vehicle on a level surface and check if it is sitting lower on one side or is generally lopsided. 
• Locate the springs: Find the springs, which are typically located around the shock absorbers near the wheels. 
• Inspect the entire spring: Carefully examine the entire length of the spring, looking for any cracks, deep scratches, rust, or missing pieces. Pay close attention to the top and bottom ends where breaks often occur. 
• Check for unevenness: Look for unevenness in the suspension, such as a noticeable dip or lean, which could indicate a broken or worn-out spring. 

You can watch this video to see how to check the ride height of your vehicle to identify potential issues with coil springs: 59sEuropean Auto RepairYouTube · Dec 29, 2022
Load and rate testing

• Set up the test: For a more technical test, you can use a setup to measure force and deflection. 
  • Securely attach a ruler to a wall and a stick to the spring to act as a pointer. 
  • Place the spring on the floor with the pointer next to the ruler. 
• Take a static measurement: Record the initial position of the pointer on the ruler before adding any weight. 
• Apply a consistent load: Apply a known, consistent weight to the top of the spring. 
• Take a loaded measurement: Record the new position of the pointer on the ruler. 
• Calculate the deflection: Subtract the static measurement from the loaded measurement to find the deflection amount (xx𝑥). 
• Determine the spring rate: You can calculate the spring rate, which is the force per unit of deflection, by dividing the weight applied by the deflection distance (xx𝑥). Professional testing equipment uses load cells and displacement sensors for greater accuracy. 

How long should coil springs last?

Coil springs can last the lifetime of the vehicle, but they typically last 60,000 to 90,000 miles under normal conditions. Their lifespan depends heavily on factors like driving habits, road conditions, climate, and vehicle load. 
Factors that affect coil spring lifespan

• Driving conditions: Rough roads with potholes and speed bumps, or even frequent driving over speed bumps, cause more stress and wear them out faster. 
• Vehicle load: Consistently carrying heavy loads or towing will put extra strain on the springs, causing them to sag or break prematurely. 
• Climate: Road salt used in winter can cause corrosion and rust, weakening the metal and increasing the risk of snapping. 
• Driving habits: Aggressive driving, such as hard cornering or sudden braking, puts more stress on the suspension system. 
• Other suspension components: Ignored or worn-out shocks and struts can cause a coil spring to weaken over time because they aren't providing the proper support, leading to clunking or "bottoming out" sounds. 

Signs of failing coil springs

• Uneven ride height: One corner of your car sits noticeably lower than the others. 
• Loud noises: You hear clunking or knocking sounds, especially when going over bumps. 
• Poor handling: The car pulls to one side or the steering feels impaired. 
• Bottoming out: The suspension feels like it's hitting its limits on bumps and inclines. 

What is the average cost of replacing a coil spring?

The cost to replace a coil spring typically ranges from $350 to $800 for a single spring, or $225 to $500 each for a pair, including parts and labor. Parts alone can cost between $35 and $645, with labor costing around $133 to $168. Replacing all four springs will increase the total cost.
 
Factors affecting cost

• Number of springs: Replacing one or two springs is cheaper than replacing all four. 
• Vehicle make and model: Some cars require more expensive or specialized parts. 
• Part brand: Aftermarket parts are often cheaper than OEM (Original Equipment Manufacturer) parts. 
• Labor rates: Costs vary based on the mechanic's hourly rate and the time it takes. 
• Other services: If you need other suspension components, like shocks or struts, replaced at the same time, the cost will be higher. 

Replacement options and tips

• DIY: Replacing coil springs yourself can save a significant amount on labor, but requires specific tools like a coil spring compressor and a high level of safety knowledge. 
• Replace in pairs: It is strongly recommended to replace coil springs in pairs (either front or rear) to ensure the vehicle's suspension is balanced. 
• Shop around: Get quotes from different repair shops to compare prices for both parts and labor. 
• Check for other damage: While you're having the springs replaced, it's a good opportunity to have other suspension components inspected for wear or damage. 

Signs of a bad coil spring
Sagging or leaning on one side, Excessive bouncing or body roll, Uneven tire wear, The vehicle bottoms out over bumps, and Visible rust or cracks on the spring.