Ford 9.75 4.10 Rear Axle Assembly

The Zumbrota RAA435-2021X1H-P is a rear axle assembly built for enhanced drivetrain performance, suitable for applications requiring stronger traction, higher speeds, and increased towing capabilities. This unit is designed for the Ford 9.75 axle and comes with a 4.10 gear ratio and a Duragrip limited-slip differential. Zumbrota meticulously remanufactures these assemblies, ensuring each component meets stringent quality standards. Every axle assembly undergoes thorough inspection for straightness, cracks, and surface wear. All internal components, including ring and pinions, gears, clutches, and carriers, are inspected and tested. To guarantee precision and longevity, all bearings and seals are replaced, and gears are inspected for optimal tooth contact patterns and correct rolling torque. The assembly process includes an exclusive hydro-blast rinse and sandblasting procedure, followed by a proprietary deep cleaning method. This specific assembly is intended for 2000-2004 Ford F-150 models equipped with the 9.75 rear axle. It features a nodular steel ZPA differential cover for added strength and protection. The unit is not pre-filled with oil, requiring the owner to add the appropriate lubricant post-installation.