KYB 553178 Shock Absorber - Rear

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

The KYB Gas-a-Just 553178 is a rear suspension shock absorber built as an OE monotube replacement for select Mercedes-Benz applications. It is engineered to restore original ride control while adding firmer damping response for vehicles that carry load, tow, or run larger wheels and tires.

Key Features

• Monotube shock design with separate hydraulic and high-pressure gas chambers for responsive control
• Up to 25% more damping performance than original equipment shocks
• High-pressure nitrogen gas helps deliver fade-resistant operation and quicker response
• Triple chrome plated piston rod helps reduce seal wear and fluid leakage
• Designed specifically for Mercedes-Benz rear suspension applications
• Dust cover included
• B-stop and R-stop included in the design

Product Details

Gas-a-Just is KYB’s monotube shock absorber line for drivers who want OE-style fitment with more immediate damping response. The 553178 uses an air-free hydraulic working area for control and a separate gas chamber with a floating piston to maintain consistent performance during normal driving and sudden suspension movement. This makes it a practical choice for Mercedes-Benz E-Class, 300-series, and 190E rear suspension service where original ride quality and steering response matter. This part cross-references Monroe Shocks & Struts 39001 for the same application.

What It Helps Address

• Excessive rear-end bounce after bumps
• Reduced control from worn OE rear shocks
• Fluid leakage from aging shock seals
• Soft or delayed response in loaded driving conditions
• Loss of stability on Mercedes-Benz rear suspension systems

Installation Notes and Fitment

Fits 1995 Mercedes-Benz E300, rear; 1994-1995 Mercedes-Benz E320, rear; 1994-1995 Mercedes-Benz E420, rear; 1988-1993 Mercedes-Benz 300CE, rear; 1990-1993 Mercedes-Benz 300D, rear; 1987 Mercedes-Benz 300D, rear; 1986-1993 Mercedes-Benz 300E, rear; 1992-1993 Mercedes-Benz 300SD, rear; 1991-1993 Mercedes-Benz 300SE, rear; 1992-1993 Mercedes-Benz 400E, rear; 1991 Mercedes-Benz 300SEL, rear; 1987-1989 Mercedes-Benz 260E, rear; 1986-1987 Mercedes-Benz 190E, rear.

Installation on some Mercedes-Benz models requires following the manufacturer’s instructions for the suspension strut and coil spring assembly. Verify rear application, mount style, and vehicle configuration before replacement. Part number 553178 should be matched to the exact rear fitment listed for your vehicle.

Quality Assurance

KYB designs Gas-a-Just shocks as OE monotube replacements with application-specific valving and components for Mercedes-Benz. The monotube construction, high-pressure gas separation, and chrome piston rod are used to support consistent damping and reduced seal wear in daily driving and heavier-duty use.