KYB 5550040 Suspension Shock Absorber - Rear

KYB Gas-a-just Shock Absorber

The KYB Gas-a-just shock absorber, part number 5550040, is a monotube suspension shock built for direct rear replacement applications. It is engineered for responsive control and consistent damping, with fitment for select Chevrolet Silverado 1500 and GMC Sierra 1500 trucks.

Key Features

• Monotube shock absorber design for responsive suspension control.
• Separate hydraulic and high-pressure gas chambers for consistent performance.
• Resists fade caused by aeration during repeated suspension movement.
• Includes a dust cover for added protection.
• Lower and upper E2 mounts: 14.6 x 42.

Detailed Description

KYB Gas-a-just shocks use an air-free hydraulic piston and valve area for immediate response, while a separate high-pressure nitrogen gas chamber adds performance on demand. That design helps maintain control without the fade associated with aeration in conventional twin-tube shocks. Part number 5550040 is specified for rear applications on 2019-2021 Chevrolet Silverado 1500, 2022 Chevrolet Silverado 1500 LTD, 2019-2021 GMC Sierra 1500, and 2022 GMC Sierra 1500 Limited. This part cross-references Monroe Shocks & Struts 552001 for the same application.

Common Issues It Can Address

• Excessive bounce after bumps or dips.
• Reduced rear suspension control under load.
• Inconsistent damping during repeated road impacts.
• Worn shock performance from age and mileage.
• Loss of ride stability on rough pavement.

Installation Notes and Tips

Verify rear fitment by year, make, model, and notes before ordering. Confirm the compressed length, extended length, and mount style match the original shock absorber. Inspect surrounding suspension components for wear before installation, and follow the vehicle service procedure for proper torque and alignment.

Quality Assurance

KYB is known for OE-style suspension engineering, and the Gas-a-just line is built around a monotube design that prioritizes control and consistent damping. Part number 5550040 is supported by the listed application data for the Silverado 1500 and Sierra 1500 platform.