KYB KG4522 Shock Absorber - Front

KYB Gas-a-Just Front Shock Absorber

The KYB Gas-a-Just KG4522 is a monotube suspension shock absorber built to restore OE-style control on select Mercedes-Benz models. It uses separate hydraulic and high-pressure gas chambers for responsive damping, stable ride quality, and quicker steering response during everyday driving.

Compatible With 1975 Mercedes-Benz 300D front, 1981 Mercedes-Benz 380SLC front, and 1981-1985 Mercedes-Benz 380SL front. This part cross-references Monroe Shocks & Struts (e.g., 39030) for the same application.

Key Features

• Monotube design with separate gas and oil chambers for fade-resistant operation
• Up to 25% more damping performance than original equipment shocks
• High-pressure nitrogen gas helps deliver quicker response and improved steering feel
• Triple chrome plated piston rod helps reduce seal wear and fluid leakage
• Built for Mercedes-Benz applications with valving matched to the vehicle
• Includes dust cover, B-stop, and R-stop
• Designed for vehicles that work, tow, or use larger, heavier tires and wheels

Product Details

Gas-a-Just is KYB’s monotube shock line for drivers who want firmer control without giving up normal-road comfort. The KG4522 uses an air-free hydraulic working area for consistent damping and a separate nitrogen gas section with a floating piston to maintain pressure and reduce fade. That design helps the shock react quickly when road conditions change, which is important on older Mercedes-Benz suspension systems that rely on precise damping to maintain ride quality and chassis control. The KYB Gas-a-Just KG4522 is a direct-fit suspension shock absorber for the front of 1975 Mercedes-Benz 300D, 1981 Mercedes-Benz 380SLC, and 1981-1985 Mercedes-Benz 380SL.

What It Helps Address

• Excessive front-end bounce after bumps
• Reduced steering response or loose road feel
• Shock fade during repeated suspension movement
• Fluid leakage caused by seal wear
• Loss of control from worn OE-style damping

Installation Notes

Install at the front position only. Follow the manufacturer’s instructions and replace the suspension strut and coil spring assembly as specified for these Mercedes-Benz applications. Verify compressed length, extended length, and mount style before installation: compressed length 13.19 in., extended length 19.17 in., stroke length 5.98 in. Upper mount type is S1 and lower mount type is SSPECIAL.

Quality Assurance

KYB designs Gas-a-Just shocks as OE monotube replacements to restore original suspension capability and maintain consistent damping performance. The higher gas pressure and monotube construction are intended to support stable operation and help electronic safety systems perform as designed when the suspension is operating correctly.