Arnott Air Suspension Coil Conversion Kit Part No C-3020: A Practical Replacement Guide

If you're dealing with a failing air suspension system on your luxury SUV or sedan, the Arnott Air Suspension Coil Conversion Kit Part No C-3020 is a popular aftermarket solution. This kit replaces the factory air springs with conventional coil springs and eliminates the air compressor, valve block, and associated plumbing. It’s designed for specific vehicles, often from brands like Mercedes-Benz, BMW, or Audi, where the original air ride system becomes unreliable and expensive to repair. This article explains what the C-3020 kit includes, which vehicles it fits, the pros and cons of converting, and what to expect during installation.

What Is the Arnott C-3020 Coil Conversion Kit?

The Arnott C-3020 is a complete coil spring conversion kit that removes the factory air suspension components and replaces them with steel coil springs and new shock absorbers. Unlike repairing individual air springs or the compressor, this conversion gives you a permanent, maintenance-free suspension setup. The kit typically includes:

• Two coil spring assemblies (front or rear, depending on application)
• New shock absorbers matched to the spring rate
• Necessary hardware such as spring seats, isolators, and bump stops
• Instructions for installation

Arnott is known for engineering these kits to maintain near-original ride height and handling characteristics. The C-3020 is often a direct bolt-on kit, meaning no modifications to the vehicle’s structure are required.

Why Consider a Coil Conversion?

Reliability Issues with Air Suspension

Factory air suspension systems offer a smooth ride and adjustable height, but they have common failure points. Air springs develop leaks, compressors burn out, and electronic sensors fail. Replacing individual components can cost thousands of dollars, and the system may still fail again. A coil conversion eliminates these failure points entirely.

Cost Savings Over Time

The Arnott C-3020 kit is significantly cheaper than replacing all air suspension components with OEM parts. Installation labor is also simpler because there’s no need to bleed or program the air system. Once installed, you have no ongoing maintenance costs for compressors or air lines.

Improved Ride Quality for Some Drivers

Many drivers find that a well-engineered coil conversion actually improves ride quality over a worn-out air system. The Arnott kit is tuned to provide a comfortable ride while reducing body roll and nose dive under braking. However, it won’t be identical to a perfectly functioning air suspension – it will be firmer and more traditional.

Which Vehicles Does the C-3020 Fit?

The Arnott C-3020 is vehicle-specific. It’s crucial to confirm fitment before purchasing. Common applications include:

• Mercedes-Benz S-Class (W220, W221) – front or rear
• Mercedes-Benz E-Class (W211) – rear
• BMW 7 Series (E65/E66) – front or rear
• Audi A8 (D3) – front or rear
• Range Rover L322 – rear

Arnott’s website provides a detailed fitment guide. The C-3020 often refers to the front conversion for certain models, but always verify using your vehicle’s year, make, and model. Some kits are sold as pairs for front or rear axles, so you may need two kits for a complete conversion.

Installation Considerations

Difficulty Level

Installing the Arnott C-3020 kit is a moderate to advanced DIY job if you have mechanical experience. You’ll need to safely lift and support the vehicle, disconnect air lines and electrical connectors, remove the old air springs, and bolt in the new coils. A professional mechanic can complete the job in 4 to 6 hours for one axle.

What to Keep in Mind

• Warning lights: After conversion, the air suspension warning light will remain illuminated because the ECU expects signals from the air system. Some drivers ignore the light; others install a resistor or use a programmer to clear the error. Arnott sometimes provides instructions for handling this.
• Ride height: The kit is designed to maintain stock ride height, but slight variations can occur. Ensure the spring seats are correctly positioned.
• Shock absorbers: The included shocks are specific to the conversion and may not be adjustable. If you want variable damping, you’ll need to explore other options.

Pros and Cons of the Arnott C-3020

Pros

• Eliminates air suspension failures – no more leaks, compressor failures, or sensor issues.
• Cost-effective – much less than OEM air suspension replacement.
• Bolt-on installation – no cutting or welding required.
• Aftersales support – Arnott offers a limited lifetime warranty on many of their kits.

Cons

• Loss of adjustability – you lose ride height adjustment and adaptive damping (if equipped).
• Dashboard warning light – may cause a persistent check suspension light.
• Ride quality changes – the ride will be firmer; some may miss the “floating” feel of air.
• Resale value – some buyers prefer original air suspension, though others see conversion as a plus.

Where to Buy the Arnott C-3020

Arnott kits are sold through authorized dealers, automotive parts retailers, and specialty suspension shops. You can also order directly from Arnott’s website. Prices vary, but expect to pay between $800 and $1,500 per axle depending on the application. Always check the warranty terms and return policy before purchasing.

Final Recommendation

The Arnott Air Suspension Coil Conversion Kit Part No C-3020 is a smart choice for owners of vehicles with chronic air suspension problems who want a permanent, lower-cost fix. It’s especially ideal if you plan to keep the car for several more years and want to avoid repeated repair bills. However, if you rely on ride height adjustability for towing or off-road use, or if you prefer the original plush ride, a coil conversion may not be for you. Before buying, confirm fitment with your vehicle’s VIN and consider whether the dashboard warning light will bother you. For most drivers, the peace of mind provided by a reliable coil spring suspension outweighs the loss of air ride features.