KYB 551134 Suspension Strut - Front

KYB Gas-a-Just Front Strut for Ford F-150

The KYB Gas-a-Just 551134 is a front suspension strut built for 2009-2013 Ford F-150 trucks with a monotube performance upgrade and no Heavy Duty Payload Package. It is engineered for drivers who need firmer control, quicker response, and consistent damping in everyday driving and demanding use.

Key Features

• Monotube design separates gas and oil for fade-resistant operation and immediate response
• Up to 25% more damping performance than original equipment shocks
• Valving and components are tuned specifically for Ford F-150 applications
• Higher gas pressure improves steering response and suspension control
• Triple chrome plated piston rod helps reduce seal wear and fluid leakage
• Supports vehicles that tow, work, or run larger and heavier tires and wheels
• Helps maintain suspension behavior needed by electronic safety systems

Product Details

KYB Gas-a-Just 551134 uses two separate working chambers: an air-free hydraulic section for control and a high-pressure nitrogen gas chamber with a floating piston for ride comfort and instant performance when suspension demand increases. This design is intended to deliver more consistent damping than a traditional twin-tube layout, especially on a Ford F-150 that sees load changes, rough pavement, or upgraded wheel and tire packages. This part cross-references Monroe Shocks & Struts 71141 for the same application.

Fits 2009-2013 Ford F-150, front, monotube performance upgrade; w/o Heavy Duty Payload Package; Gas-a-just. KYB 551134 is also referenced by Ford OE numbers 9L3Z18124BE, AL3Z18124AA, and AL3Z18124BA.

Common Problems This Part Can Address

• Excessive front-end bounce over bumps and expansion joints
• Reduced steering response during lane changes or braking
• Shock fade from heat buildup or aeration in demanding use
• Uneven control after adding heavier tires and wheels
• Loss of suspension consistency on work trucks and tow vehicles

Installation Notes and Tips

Verify the vehicle is a 2009-2013 Ford F-150 with the front monotube performance upgrade and without the Heavy Duty Payload Package before ordering. Confirm mount dimensions and suspension configuration against the original unit, including compressed length 16.41, extended length 20.74, and stroke length 4.33. Upper mount type is 12X1.25 and lower mount type is E2(20X60). Dust cover, internal rebound spring, and B-stop are not included or specified for this part.

Quality Assurance

KYB designs the Gas-a-Just line for controlled damping, reduced fade, and stable performance under changing road and load conditions. The 551134 follows the brand’s monotube performance approach for Ford F-150 front suspension service and replacement.