KYB KG5506 Shock Absorber - Rear

KYB Gas-a-Just Rear Shock for Classic GM

The KYB Gas-a-Just KG5506 is a monotube rear shock absorber built for classic GM cars that need firmer control and consistent damping. It is designed to respond quickly under load while maintaining a comfortable ride during normal driving.

For Chevrolet Nova, Buick Skylark, Oldsmobile Omega, Pontiac Phoenix, and Cadillac Seville rear suspension applications, the KG5506 adds performance-focused damping without changing the vehicle’s original shock location.

Key Features

• Up to 25% more damping performance than original equipment shocks
• Monotube design separates gas and oil for fade-resistant operation and quick response
• High-pressure nitrogen gas chamber adds instant performance when suspension demand increases
• Triple chrome plated piston rod helps reduce seal wear and fluid leakage
• Valving and components are tuned for classic GM cars
• Improves steering response through higher gas pressure and faster reaction
• Supports vehicles that work, tow, or use larger, heavier tires and wheels
• Compatible with electronic safety systems that rely on proper suspension behavior

Product Details

The Gas-a-Just line uses a two-chamber monotube layout: an air-free hydraulic section for control and a separate high-pressure gas section with a floating piston for ride comfort and immediate damping response. This design helps maintain consistent performance under repeated suspension movement, which is useful on older rear suspensions that need tighter body control. KYB KG5506 is a direct-fit suspension shock absorber for rear applications on 1969-1973 Chevrolet Nova, rear; 1974-1979 Chevrolet Nova, rear; 1975-1979 Buick Skylark, rear; 1974-1979 Oldsmobile Omega, rear; 1977-1979 Pontiac Phoenix, rear; and 1976-1979 Cadillac Seville, rear. This part cross-references Monroe Shocks & Struts 5931 for the same application.

What It Helps Address

• Excessive rear-end bounce after bumps
• Reduced control during cornering or lane changes
• Shock fade from repeated suspension movement
• Soft or unstable handling on heavier wheel and tire setups
• Loss of damping performance from worn OE-style shocks

Installation Notes and Tips

Verify compressed length, extended length, and mount style before installation: compressed length 12.95 in, extended length 20.83 in, stroke length 7.87 in, lower mount type E2(11.1X41), upper mount type E3(61.6X87X0). Dust cover is included. This shock is intended for rear placement only, and fitment should be matched to the exact vehicle year and suspension configuration listed above.

Quality Assurance

KYB designs the Gas-a-Just line for consistent damping control, reduced fade, and long-term seal protection through its monotube construction and chrome-plated piston rod. The KG5506 is engineered for classic GM rear suspension applications where stable ride control and predictable response matter.