KYB 553306 Shock Absorber - Rear

KYB Gas-a-just Rear Shock for Mercedes-Benz C-Class

KYB Gas-a-just 553306 is a monotube suspension shock absorber built as an OE-style replacement for select Mercedes-Benz C-Class rear applications. It is engineered to restore original control and handling while delivering quick response for vehicles that carry heavier wheels, tow, or see more demanding driving.

Key Features

• Monotube OEM replacement design for consistent damping response
• Separate hydraulic and high-pressure nitrogen gas chambers for fade-resistant operation
• Triple chrome plated piston rod helps reduce seal wear and fluid leakage
• Higher gas pressure improves steering response and suspension control
• Supports electronic safety systems by helping the suspension operate as designed
• Includes dust cover, B-stop, and R-stop
• Compressed length: 17.71 in; extended length: 21.81 in; stroke length: 4.1 in
• Lower mount type: E2(10X40); upper mount type: S1

Product Details

The KYB Gas-a-just line is a monotube shock absorber series focused on restoring OE ride characteristics with added control under load. Part number 553306 uses an air-free hydraulic working area for responsiveness and a separate high-pressure nitrogen gas section with a floating piston to maintain stable damping during normal driving and deliver immediate performance when conditions change. This makes it a practical rear shock choice for Mercedes-Benz C280, C350, C55 AMG, C230, C240, and C320 models where precise rear suspension control matters.

This part cross-references Monroe Shocks & Struts 39047 for the same application.

What It Helps Address

• Excessive rear bounce or poor damping control
• Reduced steering response from worn rear shocks
• Fluid leakage caused by seal wear
• Fade during repeated suspension movement or heavier-duty use
• Loss of ride stability on Mercedes-Benz C-Class rear suspension setups

Installation Notes

Fits 2006-2007 Mercedes-Benz C280, rear; 2006-2007 Mercedes-Benz C350, rear; 2005-2006 Mercedes-Benz C55 AMG, rear; 2002-2005 Mercedes-Benz C230, rear with sport suspension; 2001-2005 Mercedes-Benz C240, rear; 2003-2005 Mercedes-Benz C240, rear excluding self-leveling suspension; 2005 Mercedes-Benz C320, rear excluding self-leveling suspension; and 2001-2004 Mercedes-Benz C320, rear without self-leveling suspension. Replace the suspension strut and coil spring assembly according to the manufacturer’s instructions where specified. Verify mount style and suspension configuration before installation.

Quality Assurance

KYB designs the Gas-a-just line as an OE monotube replacement to help restore the vehicle manufacturer’s intended suspension behavior. Part number 553306 is built for direct-fit rear applications listed above and is engineered to support consistent damping performance in the Mercedes-Benz C-Class platform.