KYB KG4163 Shock Absorber - Rear

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

The KYB Gas-a-just KG4163 is a rear suspension shock absorber for select Nissan Pathfinder and INFINITI QX4 applications. It uses a monotube design with separate gas and oil chambers to deliver quick response, consistent damping, and stable ride control for vehicles that work, tow, or run larger wheels and tires.

Key Features

• Monotube shock absorber design for direct response and fade-resistant operation
• Up to 25% more damping performance than original equipment shocks
• High-pressure nitrogen gas and hydraulic chambers are separated for consistent control
• Triple chrome plated piston rod helps reduce seal wear and fluid leakage
• Valving and components are tuned for Nissan Pathfinder and INFINITI QX4 rear applications
• Dust cover included
• Part number KG4163

Product Details

Gas-a-just is KYB’s performance-oriented shock line, built around a high-pressure monotube layout that reacts quickly to suspension movement. For the Nissan Pathfinder and INFINITI QX4, KG4163 adds damping capacity over OE-style twin-tube designs while maintaining a controlled ride during normal driving. The monotube construction separates the gas and oil to reduce aeration, which helps maintain consistent performance under repeated suspension movement. This part number, KG4163, is a rear shock absorber engineered for the listed applications and is a direct fit for the specified model years.

This part cross-references Monroe Shocks & Struts 37204 for the same application.

What It Helps Address

• Excessive rear bounce after bumps or dips
• Reduced steering response from worn rear damping
• Ride fade during towing or heavier-duty use
• Suspension instability with larger tires and wheels
• Oil leakage or seal wear from aging shock absorbers

Installation Notes and Tips

• Fits 2000-2004 Nissan Pathfinder, rear.
• Fits 2000-2003 INFINITI QX4, rear.
• Fits 1999 INFINITI QX4, rear, from 12/1998.
• Fits 1999 Nissan Pathfinder, rear, from 12/1998.
• Verify rear suspension configuration and mounting style before installation.
• Inspect related bushings, mounts, and hardware condition during shock replacement.
• Confirm the vehicle is within the listed year and production-date range before ordering.

Quality Assurance

KYB is a major OE suspension supplier, and the Gas-a-just line is built to meet the demands of vehicles that see regular load, tow, or performance use. The KG4163 uses a high-pressure monotube design, a triple chrome plated piston rod, and application-specific valving for the Pathfinder and QX4 rear suspension.