KYB KG5533 Shock Absorber - Rear

KYB Gas-a-Just Rear Shock for Mercedes-Benz

The KYB Gas-a-Just KG5533 is a rear suspension shock absorber built for Mercedes-Benz applications that need OE-style control with added damping response. It is a monotube replacement for the original rear shock on select Mercedes-Benz 300SE, 300SEL, 300SDL, 300SD, and 300D models.

Gas-a-Just is KYB’s monotube shock line, using separate hydraulic and high-pressure gas chambers to deliver responsive damping, fade resistance, and consistent control during normal driving and load changes. The KG5533 is a direct-fit rear shock for W126 chassis applications listed below.

Key Features

• Rear suspension shock absorber for select Mercedes-Benz models
• Monotube design separates gas and oil for consistent damping response
• Up to 25% more damping performance than original equipment shocks
• Triple chrome plated piston rod helps reduce seal wear
• Higher gas pressure improves steering response and suspension control
• Designed for vehicles that work, tow, or use larger, heavier tires and wheels
• Dust cover included

Detailed Description

KYB KG5533 is engineered as an OE monotube replacement for the rear suspension on Mercedes-Benz vehicles that require stable ride control and predictable handling. The Gas-a-Just design uses an air-free hydraulic working area for responsiveness and a separate high-pressure nitrogen chamber with a floating piston to maintain fade-free operation. This construction helps the shock react quickly when road conditions change while maintaining comfort in everyday driving. For Mercedes-Benz 300SE, 300SEL, 300SDL, 300SD, and 300D rear applications, KG5533 supports the original suspension behavior with added damping authority.

This part cross-references Monroe Shocks & Struts 39032 for the same application.

What This Shock Helps Address

• Excessive rear-end bounce after bumps or dips
• Reduced control during braking, cornering, or lane changes
• Suspension fade from repeated load or road input
• Uneven ride quality caused by worn rear shocks
• Delayed response in heavier Mercedes-Benz rear suspension applications

Installation Notes and Fitment

• Fits 1988-1991 Mercedes-Benz 300SE, Rear; Recommended OEM Replacement; (W126)(Exc.Hydromat Susp.); Gas-a-just
• Fits 1988-1991 Mercedes-Benz 300SEL, Rear; Recommended OEM Replacement; (W126)(Exc.Hydromat Susp.); Gas-a-just
• Fits 1986-1987 Mercedes-Benz 300SDL, Rear; Recommended OEM Replacement; (W126)(Exc.Hydromat Susp.); Gas-a-just
• Fits 1981-1985 Mercedes-Benz 300SD, Rear; Recommended OEM Replacement; (W126)(Exc.Hydromat Susp.); Gas-a-just
• Fits 1975 Mercedes-Benz 300D, Rear; Replace suspension strut and coil spring assembly according to manufacturer's instructions; Gas-a-just

Verify compressed length 11.06 in., extended length 17.76 in., and stroke length 6.69 in. before installation. Lower mount type is E3(61.6X87X0) and upper mount type is S1. This rear shock absorber is intended for the listed Mercedes-Benz W126 applications and should be matched to the vehicle’s suspension configuration before service.

Quality Assurance

KYB designs the Gas-a-Just line as an OE-style monotube replacement with application-specific valving and components for Mercedes-Benz fitment. The KG5533 is built to support consistent damping performance and suspension control in the listed rear applications.