KYB KG54318 Shock Absorber - Rear

KYB Gas-a-just Rear Shock for Pathfinder and QX4

The KYB Gas-a-just KG54318 is a rear monotube shock absorber built for 1996-1999 Nissan Pathfinder and 1997-1999 INFINITI QX4 applications with standard suspension. It is engineered to add damping response over original equipment while maintaining a controlled ride for daily driving, towing, and heavier wheel-and-tire setups.

The Gas-a-just line uses a monotube design with separate gas and oil chambers for quick response and fade-resistant operation. For Pathfinder and QX4 owners looking for a rear shock upgrade, KG54318 is built around the vehicle-specific valving and mounting dimensions needed for direct replacement service.

Key Features

• Adds up to 25% more damping performance over original equipment shocks
• Vehicle-specific components and valving for Nissan Pathfinder and INFINITI QX4 rear applications
• High-pressure monotube construction separates gas and oil for consistent response
• Designed for vehicles that work, tow, or run larger, heavier tires and wheels
• Triple chrome plated piston rod helps reduce seal wear and fluid leakage
• Improved gas pressure supports quicker steering response and suspension control
• Supports proper operation of electronic safety systems by helping the suspension perform as designed
• Compressed length: 14.57 in; extended length: 22.8 in; stroke length: 8.23 in
• Lower mount type: E2(12X48); upper mount type: E2(16X42)
• Dust cover included

Product Details

KYB Gas-a-just shocks are designed to deliver firmer control than a conventional twin-tube design by using a high-pressure monotube layout with an air-free hydraulic working area and a separate nitrogen gas chamber. That construction helps the KG54318 react quickly to suspension movement, resist fade from aeration, and maintain stable damping under load. This makes it a practical rear shock absorber choice for Nissan Pathfinder and INFINITI QX4 owners who want more controlled handling without changing the vehicle’s basic suspension layout.

This part cross-references Monroe Shocks & Struts 37158 for the same application.

What It Helps Address

• Rear-end bounce or excessive oscillation after bumps
• Reduced control when carrying cargo or towing
• Soft or inconsistent damping from worn original shocks
• Delayed response during lane changes or braking transitions
• Ride instability from larger, heavier tires and wheels

Installation Notes and Fitment

Fits 1996-1998 Nissan Pathfinder, rear. Fits 1997-1998 INFINITI QX4, rear. Fits 1999 Nissan Pathfinder, rear, monotube performance upgrade; excludes electronic adjustable suspension; to 11/98. Fits 1999 INFINITI QX4, rear, monotube performance upgrade; excludes electronic adjustable suspension; to 11/98.

Before installation, verify rear suspension configuration and confirm the vehicle is not equipped with electronic adjustable suspension where excluded. Match the mount types and compressed/extended lengths to the original shock position before final assembly. For best results, inspect related rear suspension components such as bushings and mounts during replacement.

Quality Assurance

KYB designs the Gas-a-just line around monotube performance and vehicle-specific valving for consistent damping control. The KG54318 is built to support the suspension performance expected on Pathfinder and QX4 rear applications, with construction details aimed at reducing seal wear and maintaining fade-resistant operation.