Air Suspension to Coil Spring Kit For 2007-2013 W221 S350 S500 S550 S600 RWD

Application

Compatible for Mercedes-Benz S-Class W221 RWD 2007-2013 S350, S500, S550, S600 Excludes 4 Matic

Specification

Condition: New
Shock Absorber Type: Gas Pressure
Product Type: Air Spring to Coil Spring Conversion Kit
Items Included: Strut Assembly Kit, Bushing,Coil Spring,Mount,Shock,Strut
Material: High-tensile steel
Adjustability: No
Shock Absorber System: Twin-Tube
Strut overall length Front: 613 mm
Strut overall length Rear: 882 mm
Front Shock Body Diameter: Φ50 mm
Rear Shock Body Diameter: Φ50 mm
Front Piston Rod diameter: Φ18 mm
Rear Piston Rod diameter: Φ18 mm
Spring Rate Front: 5.3 kg/mm(135 lbs/in)
Spring Rate Rear: 5.3 kg/mm(135 lbs/in)
Front spring inner diameter: 70.5-82.5-77 mm
Rear spring inner diameter: 70.5-82.5-77 mm
Spring length Front: 380 mm
Spring length Rear: 380 mm
Front Shock Travel Length: 140 mm
Rear Shock Travel Length: 220 mm
Placement on Vehicle: Front,Left,Rear,Right

Package included

Package included：
2x Front struts
2x Rear struts
1x Electronic Module

Feature

1. Eliminates Costly Air Suspension Failures – Permanently replaces unreliable air springs and compressors with durable coil springs, ending repeated repair bills and preventing sudden suspension collapse.

2. Significantly Lowers Maintenance Costs – Converts complex, expensive-to-fix air suspension into a simple, proven coil spring system, drastically reducing long-term ownership costs.

3. Improves Driving Stability & Handling – Provides more consistent ride height and firmer suspension response for enhanced control, especially under load or during cornering.

4. Guaranteed Ride Height & Load Capacity – Maintains correct vehicle height regardless of temperature or system leaks, ensuring reliable load leveling and towing capability.

5. Simple, Permanent Solution – A straightforward installation kit designed for a one-time conversion, offering peace of mind and freeing you from constant system monitoring.

6. Direct Bolt-On Installation – Uses factory mounting points—no welding or modifications required.

7. Firm, Sport-Tuned Ride – Designed with performance-oriented spring rates for better body control without sacrificing daily usability.

interchange number

31-013600-4-S, 61JZHW86