Product Details

The Riaction GT1 Coilovers for the 1998-2006 Mercedes-Benz SL-Class R129 deliver a premium, adjustable suspension upgrade built for drivers who want more from their SL-Class R129 than the factory setup can offer. These Mercedes-Benz SL-Class coilovers are engineered to pair street comfort with canyon and track capability, giving you the stance, handling, and adjustability you've been chasing without compromising daily driveability. Whether you track your R129 SL-Class on weekends or log daily miles, this R129 coilover kit dials in ride height and damping to match how you actually use the car.

Every GT1 set features a monotube damper with 32 levels of damping adjustment, so you can tune ride quality to match the road, the weather, or your driving mood. Full-length ride-height adjustment separates preload from ride height — meaning you can drop the SL-Class R129 to the height you want while preserving spring travel and shock stroke. Riaction coilovers for the 1998-2006 Mercedes-Benz SL-Class are fully rebuildable and backed by a 2-year warranty, making the GT1 a long-term suspension investment rather than a disposable upgrade.

GT1 Series Technology

  • Monotube linear damper with seamless 52mm electroplated carbon steel body
  • 32-level damping adjustment (1-Way)
  • 44mm CNC-machined 6061 aluminum high-flow piston
  • 20mm piston rod for MacPherson applications / 14mm for non-MacPherson
  • SAE9254 cold-wound linear main springs
  • Multi-thickness valving shims for consistent damping
  • Polyurethane oil seals and 7.5W suspension fluid
  • Low-gas-pressure design for improved compliance
  • Fully rebuildable — built to be serviced, not replaced

Features

  • Full-length ride-height adjustment (preload-independent)
  • 32 levels of damping adjustment
  • Optional Swift Springs upgrade (sold separately)
  • 2-year limited warranty
Specifications
Part Number MZ-044-LT
Part Name Riaction GT1 Coilovers
Vehicle 1998-2006 Mercedes-Benz SL-Class
Chassis Code R129
Adjustment Type 1-Way
Ride-Height Adjustable Yes
Spring Rate - Front 12 Kg/mm
Spring Rate - Rear 8 Kg/mm
Top Mounts - Front OEM
Top Mounts - Rear OEM
Camber Plates - Front No
Camber Plates - Rear No
Suspension Design - Front True Coilover
Suspension Design - Rear True Coilover
Vehicle Fitment
  • 1998 Mercedes-Benz SL-Class (R129)
  • 1999 Mercedes-Benz SL-Class (R129)
  • 2000 Mercedes-Benz SL-Class (R129)
  • 2001 Mercedes-Benz SL-Class (R129)
  • 2002 Mercedes-Benz SL-Class (R129)
  • 2003 Mercedes-Benz SL-Class (R129)
  • 2004 Mercedes-Benz SL-Class (R129)
  • 2005 Mercedes-Benz SL-Class (R129)
  • 2006 Mercedes-Benz SL-Class (R129)

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