Firestone 4155 CoilRite Rear Air Helper Springs for Toyota Sienna/Chevy Uplander

Vehicle Fitment

• 2004-2026 Toyota Sienna (FWD only -- does NOT fit AWD or Hybrid)
• 2005-2009 Chevy Uplander
• 2005-2007 Buick Terraza
• 2005-2007 Saturn Relay

Fitment Notes

• Rear axle only
• Toyota Sienna: FWD models only -- does not fit AWD or Hybrid variants
• No drilling required
• Manual fill -- air compressor sold separately (see Air Accessory Systems)
• Replacement air spring: Firestone 6020
• Full product number: W237604155
• Installation time: 1-2 hours

Features

• Installs inside existing coil springs -- creates variable spring rate
• Levels vehicle under load
• Reduces body roll and bottoming out
• Improves braking and handling under load
• Adjustable pressure for varying loads and conditions
• Individual inflation valves -- adjust each side independently
• Durable elastic polyurethane construction
• Operating temperature range: -40°F to 180°F (-40°C to 82°C)
• Compatible with all Firestone Air Command compressor kits (sold separately)

Specifications

• Part Number: 4155 (W237604155)
• Series: Coil-Rite
• Position: Rear
• Fill Type: Manual
• Load Capacity: 500-1,000 lbs. per set
• Min. Air Pressure: 5 PSI
• Max. Air Pressure: 35 PSI
• Temperature Range: -40°F to 180°F (-40°C to 82°C)
• Material: Elastic polyurethane
• Drilling Required: No
• Replacement Air Spring: Firestone 6020

Included Components

• 2x Coil-Rite air springs
• Air line and individual inflation valves
• All mounting hardware

Product Description

The Firestone 4155 Coil-Rite is a rear air helper spring kit for the 2004-2026 Toyota Sienna (FWD only), 2005-2009 Chevy Uplander, 2005-2007 Buick Terraza, and 2005-2007 Saturn Relay. The Coil-Rite springs install inside the existing rear coil springs without drilling, creating a variable spring rate that stiffens automatically under load and softens when unloaded. The result is a leveled vehicle under heavy cargo or passenger loads, reduced body roll, and improved braking and handling effectiveness -- without altering ride quality when the vehicle is empty.

Pressure is adjusted through individual inflation valves -- the same as inflating a tire -- allowing each side to be tuned independently for uneven loads. The 5-35 PSI operating range and 500-1,000 lb load capacity cover the full range of real-world loading situations for these minivan platforms. The elastic polyurethane construction is rated for temperatures from -40°F to 180°F for year-round use. This kit is manual fill; air compressor kits (Firestone Air Command series, sold separately) can be added for cab-controlled inflation. Note the Toyota Sienna fitment covers FWD models only -- AWD and Hybrid Sienna variants are not compatible.