3.73 Ratio Rear Axle Assembly

The Zumbrota RAA435-2021J is a remanufactured axle assembly meticulously rebuilt to stringent quality standards for precision and reliability. It is designed for 9.75-inch Ford F-150 models manufactured between 2000 and 2003, featuring a 3.73 gear ratio and rear disc brakes. This assembly is Ford-built and utilizes a semi-floating axle type. Each unit undergoes thorough inspection for straightness, cracks, and surface wear. Internal components, including ring and pinions, gears, clutches, and carriers, are fully inspected and tested. All bearings and seals are replaced, and gears are examined for optimal tooth contact patterns and correct rolling torque. The gear backlash is precisely set to ensure proper lubrication and quiet operation, with axle tubes inspected for OEM straightness. Zumbrota employs an exclusive hydro-blast rinse and sandblasting procedure, followed by a proprietary deep cleaning process, to set a high standard for axle assembly remanufacturing. Key specifications include a 9.75-inch ring gear diameter, a 3.73 gear ratio, and rear disc brakes with 14mm wheel studs. The wheel bearings have a 2.992 OD. This assembly is specified as 'Without Posi Traction'. It includes the differential cover but does not come with fluid or mounting hardware and is not pre-filled with oil. The Hollander number for this unit is 435-221J. Buyers should 'Check Tag' to ensure compatibility.