What coilovers are and why you might install them
A coilover is a suspension component that combines a coil spring and a shock absorber into one unit. When you install coilovers, you replace your vehicle's factory suspension with this integrated assembly, which lets you adjust both the ride height and the stiffness of your suspension. Most people install coilovers to lower their vehicle, improve handling during cornering, or fine-tune how the car feels on different road surfaces.
The installation itself is a mechanical job that requires removing your factory suspension parts and bolting in the new coilover assembly in their place. It typically takes four to eight hours depending on your vehicle's design, whether you have the right tools, and whether you run into rusted or stuck fasteners. Many owners do this work themselves in a garage or driveway; others take the vehicle to a shop.
Key Takeaways
- Coilovers replace your factory shocks and springs as a single unit, allowing you to adjust ride height and suspension stiffness.
- The job requires lifting the vehicle safely, removing wheels and brake components, unbolting the factory assembly, and installing the new coilover in its place.
- You will need basic hand tools, a jack and jack stands, and possibly a spring compressor depending on your vehicle's suspension design.
- Wheel alignment is required after installation because changing suspension geometry affects how your wheels sit relative to the road.
- If fasteners are seized or corroded, the job takes longer; if you lack tools or experience, a shop can complete the work in a few hours.
Tools and equipment you need before starting
At minimum, you need a floor jack and jack stands to safely lift the vehicle. Never work under a car supported only by a jack—use the stands as your primary support. You also need basic hand tools: a socket set, wrenches, screwdrivers, and a torque wrench to tighten fasteners to the manufacturer's specification.
Depending on your vehicle's suspension type, you may need a spring compressor. Some coilover kits come pre-assembled with the spring already compressed and mounted to the shock, so you do not compress anything yourself. Others require you to compress the spring before removing it from the factory shock or before installing it on the new coilover. Check your kit's instructions and your vehicle's service manual to know which applies to you.
A torque wrench is essential because suspension fasteners must be tightened to a specific force, measured in foot-pounds or Newton-meters. Over-tightening can strip threads or crack components; under-tightening can cause fasteners to loosen while driving. Your vehicle's service manual lists the correct torque value for each bolt.
Step-by-step installation process
Start by parking on level ground, engaging the parking brake, and placing wheel chocks behind the rear wheels. Loosen the lug nuts on the wheel you are working on while the vehicle is still on the ground—this is easier than trying to loosen them after the wheel is in the air. Then lift the vehicle with the floor jack, place jack stands under the frame or suspension support points, and lower the vehicle onto the stands.
Remove the wheel and tire. You will now see the brake caliper, rotor, and the suspension assembly. Unbolt the brake caliper and hang it with a wire or bungee cord so it does not dangle from the brake line. Remove the brake rotor if your kit's instructions require it. Next, locate the bolts connecting the factory shock to the steering knuckle or control arm—usually two or three bolts. Unbolt these and support the shock so it does not fall.
At the top of the shock, inside the engine bay or under the hood, you will find bolts or a mounting plate connecting the shock to the vehicle's body. Unbolt these. The factory shock assembly should now come free. If a spring is still attached, you may need to compress it before removal, depending on your suspension design. Follow your kit's instructions on this step.
Install the new coilover by reversing the process: bolt the top mount to the vehicle body first, then align the bottom of the coilover with the steering knuckle or control arm and bolt it in place. Use the torque wrench to tighten all fasteners to the specification in your manual. Reinstall the brake rotor and caliper, then the wheel and tire. Lower the vehicle and repeat on the other three corners.
Adjusting ride height and suspension stiffness
Once all four coilovers are installed, you can adjust the ride height by turning the adjustment collar on the coilover body. This collar moves the spring seat up or down, which raises or lowers the vehicle. Most coilovers have a locking ring that you must loosen before turning the collar, then tighten again after adjustment to prevent the collar from rotating while driving.
Suspension stiffness is adjusted by turning the damping knob, usually located at the top or bottom of the coilover shock body. Turning it one direction increases stiffness (a firmer, less bouncy ride); turning it the other decreases stiffness (a softer, more compliant ride). Start with the middle setting and adjust from there based on how the car feels on the road. Changes are subtle and take a few drives to notice.
Make small adjustments to one corner at a time and test drive between changes. Lowering the vehicle too much can cause the suspension to bottom out over bumps or cause the wheels to rub inside the fenders. Raising it too much defeats the purpose of the coilovers. Most owners settle on a height that looks good and still clears obstacles on their regular driving routes.
Wheel alignment after installation
Changing your suspension geometry changes the angles at which your wheels sit relative to the road. This affects tire wear, steering feel, and how the vehicle handles. After installing coilovers, you must have a wheel alignment performed at a shop with alignment equipment.
The alignment technician will measure and adjust three angles: camber (tilt of the wheel), caster (forward or backward lean), and toe (whether the wheels point straight ahead or inward or outward). Some coilover kits include adjustable control arms or camber plates to allow you to dial in these angles yourself, but most vehicles require a professional alignment. The cost is typically $100 to $200 depending on your location and whether your vehicle needs adjustable parts.
Do not drive the vehicle on public roads until alignment is complete. Misaligned wheels will cause uneven tire wear, pulling to one side, and poor handling.
Common problems and how to avoid them
Seized or corroded fasteners are the most common obstacle. If a bolt will not budge, explore penetrating oil (such as PB Blaster or Liquid Wrench) and let it soak for 15 to 30 minutes. Tap the bolt gently with a hammer to help the oil penetrate, then try again. If it still will not turn, heat the area with a heat gun or hair dryer to expand the metal slightly, which can break the corrosion bond. As a last resort, you may need to drill out the bolt and install a new one.
Improper torque is another issue. If you tighten fasteners too much, you risk stripping the threads or cracking the component. If you tighten them too little, they can loosen while driving, causing noise, vibration, or loss of control. Use a torque wrench and follow your manual's specifications exactly.
Bottoming out occurs when the suspension compresses fully and the coilover body hits the bump stop or the wheel well. This usually means the ride height is set too low. Raise the vehicle slightly and test drive again. If you want a lower stance, you may need adjustable control arms or camber plates to maintain proper suspension geometry at that height.
When to take your vehicle to a shop instead
If you lack a floor jack, jack stands, or a torque wrench, renting or borrowing these tools is usually cheaper than paying a shop. However, if you are not comfortable working under a vehicle, do not have a suitable workspace, or encounter seized fasteners you cannot free, a professional shop is the safer choice.
A shop with suspension experience can complete a four-corner coilover installation in two to four hours and will handle seized fasteners, perform the alignment, and warranty the work. Expect to pay $400 to $800 in labor depending on your location and vehicle complexity. This is reasonable insurance if you are uncertain about the job or want the work done quickly.
Frequently Asked Questions
Do I need to replace other suspension parts when I install coilovers?
Not always. Coilovers replace only the shock and spring. If your control arms, sway bars, or other suspension components are worn, you can replace them separately. However, if you are lowering the vehicle significantly, adjustable control arms or camber plates may be necessary to maintain proper wheel angles and prevent tire wear issues.
Can I install coilovers on a vehicle with air suspension?
Some vehicles use air suspension instead of traditional springs and shocks. Coilover kits for these vehicles exist but are more complex because they must integrate with or replace the air system. Check whether a coilover kit exists for your specific vehicle before purchasing. If none is available, you may need to convert to a traditional suspension setup, which is a larger project.
How long do coilovers last before they need replacement?
The shock absorber inside a coilover typically lasts 50,000 to 100,000 miles depending on driving conditions and how stiffly you set the damping. The spring itself lasts much longer but can sag over time, causing the ride height to drop. If your coilovers are leaking fluid or the vehicle bounces excessively after bumps, the shock is worn and needs replacement.
Will coilovers affect my vehicle's warranty?
Installing aftermarket coilovers may void the manufacturer's suspension warranty. Some dealers will refuse to service suspension-related issues if they determine aftermarket parts are the cause. Check your warranty documentation and contact your dealer before installation if warranty coverage is important to you.
What is the difference between coilovers and lowering springs?
Lowering springs replace only the spring and work with your factory shocks. Coilovers replace both the spring and shock as one unit and allow you to adjust ride height and damping. Coilovers offer more control and adjustability but cost more. Lowering springs are cheaper but offer no damping adjustment and may not work well with lowered ride heights if your shocks are not designed for it.