KYB KG5558 Shock Absorber - Rear

KYB Gas-a-just Rear Shock for Saab 900

The KYB Gas-a-just KG5558 is a rear suspension shock absorber for Saab 900 models from 1979-1993. Built as a monotube design, it separates gas and oil for quicker response, consistent damping, and reduced fade during demanding driving.

For Saab 900 rear suspension service, the KYB Gas-a-just line adds firmer control than a standard twin-tube shock while still maintaining a controlled ride in normal use. Part number KG5558 is engineered for drivers who want improved steering response and suspension stability.

Key Features

• Fits 1979-1993 Saab 900, rear
• Monotube shock absorber design for responsive damping
• Up to 25% more damping performance over original equipment shocks
• High-pressure nitrogen gas and hydraulic chambers work separately 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
• Designed specifically for Saab applications
• Supports vehicles that work, tow, or use larger, heavier tires and wheels
• Part number KG5558

Product Details

The KYB Gas-a-just KG5558 uses a high-pressure monotube layout with an air-free hydraulic working area and a separate nitrogen gas chamber. That construction helps the shock react quickly to road inputs while maintaining consistent damping as conditions change. For Saab 900 rear suspension applications, this design is suited to drivers who want more control than a conventional OE-style twin-tube shock can provide.

This part cross-references Monroe Shocks & Struts (e.g., 39011) for the same application. The KG5558 also aligns with the rear shock needs of Saab 900 models across the 1979-1993 range.

Common Problems It Can Address

• Excessive rear-end bounce after bumps
• Reduced steering response from worn rear shocks
• Shock fade during repeated suspension movement
• Fluid leakage caused by seal wear
• Loose or unstable handling in Saab 900 rear suspension service

Installation Notes

Verify rear fitment against the vehicle’s suspension configuration before installation. The listed dimensions are compressed length 11.69 in., extended length 17.87 in., and stroke length 6.18 in. Mounting details are lower mount type E2(12X50) and upper mount type S1. This shock does not include a dust cover, internal rebound spring, or B-stop.

For best results, inspect related suspension components such as bushings, mounts, and tires before replacing the shock. Proper installation and torque procedures should follow the vehicle service manual.

Quality Assurance

KYB is known for OE-focused suspension engineering, and the Gas-a-just line uses a monotube design with separate gas and oil chambers to maintain consistent damping performance. Part number KG5558 is built to support stable rear suspension control on Saab 900 applications.