Firestone Coil-Rite Rear Air Helper Spring Kit - MPN 4108 - Select 1981-2021 GM, Ford, Lincoln, Mercury

Fits select 1981-2021 Cadillac, Chevrolet, Ford, GMC, Hummer, Lincoln, and Mercury vehicles with rear coil spring suspensions.

The Firestone Coil-Rite Air Helper Spring Kit provides a variable spring rate to manage heavy loads and improve ride quality. These air springs install directly inside your vehicle's existing rear coil springs, providing additional support that works in tandem with the factory suspension. By adjusting the air pressure, you can level your vehicle while towing or hauling, ensuring proper headlight aim, consistent steering response, and more effective braking performance even under adverse road conditions.

Made from durable, elastic polyurethane, these helper springs are designed for longevity and reliable performance in extreme climates. They allow you to fine-tune your suspension as easily as inflating a tire, offering a customizable solution for varying cargo weights.

• Supports 500–1,000 lbs per set (do not exceed vehicle GVWR)
• Constructed from high-strength, durable polyurethane
• Adjustable air pressure for varying load and road conditions
• Operating temperature range: -40°F to 180°F (-40°C to 82°C)
• Improves steering, balance, and braking effectiveness
• Reduces tire wear and prevents bottoming out
• Manufacturer Part Number: 4108