National 450308 Manual Transmission Output Shaft Seal

Manual Transmission Output Shaft Seal for Ford and Jeep

National 450308 is a manual transmission output shaft seal built with nitrile material and a Redicoat finish for sealing performance at the transmission tailshaft. It is an oil seal in the National 450000 series, sized for a 2.125-inch shaft and a 3.061-inch housing bore.

Use National 450308 when servicing Borg-Warner manual transmissions in classic Ford F-100, F-250, and F-350 trucks, as well as Jeep Wagoneer applications listed below. The part number 450308 is also a direct reference point for cross-checking manual transmission output shaft seal applications.

Key Features

• Nitrile construction for sealing durability in transmission service
• Redicoat surface treatment
• Oil seal design for manual transmission output shaft applications
• Inside diameter: 2.125 in. / 53.980 mm
• Outside diameter: 3.066 in. / 77.880 mm
• Housing bore: 3.061 in. / 77.750 mm
• Width: 0.500 in. / 12.700 mm
• National 450308 part number for catalog and fitment lookup

Detailed Description

National 450308 is a manual transmission output shaft seal engineered for Borg-Warner-equipped Ford trucks and Jeep Wagoneer models. The seal’s nitrile material and precise dimensional sizing help maintain a proper seal at the output shaft, where transmission fluid retention is critical. This part is listed for 1953-1972 Ford F-100, F-250, and F-350 applications with specific Borg-Warner T98, T98A, T18, and T18B transmissions, plus 1963-1966 Jeep Wagoneer models with Borg-Warner T89E, T89C, and T89D transmissions.

This part cross-references Gates 12259 and 21210 for the same application. National 450308 is a practical replacement choice when matching the original seal dimensions and transmission configuration on classic Ford F-100, Ford F-250, Ford F-350, and Jeep Wagoneer manual transmissions.

What It Helps Address

• Transmission fluid seepage at the output shaft
• Wet or oily residue around the tailshaft area
• Seal wear from age, heat, and mileage
• Loss of sealing integrity during manual transmission service
• Replacement needs on Borg-Warner T98, T98A, T18, T18B, and T89-series transmissions

Installation Notes and Tips

Verify shaft diameter, housing bore, and transmission type before installation. Confirm the vehicle’s Borg-Warner transmission variant and match the seal dimensions to the original unit. Clean the sealing surface and inspect the shaft for wear or scoring before installing National 450308. For fitment, use the exact application notes: Fits 1953-1955 Ford F-100, with Borg-Warner T98 Transmission; Fits 1953-1955 Ford F-250, with Borg-Warner T98 Transmission; Fits 1953-1955 Ford F-350, with Borg-Warner T98 Transmission; Fits 1956-1964 Ford F-100, Compatible with Borg-Warner T98A Transmission for Manual Transmission Output Shaft Seal; Fits 1956-1964 Ford F-250, Compatible with Borg-Warner T98A Transmission for Manual Transmission Output Shaft Seal; Fits 1956-1964 Ford F-350, Compatible with Borg-Warner T98A Transmission for Manual Transmission Output Shaft Seal; Fits 1963-1965 Jeep Wagoneer, with Borg-Warner T89D Transmission; Fits 1963-1966 Jeep Wagoneer, with Borg-Warner T89E Transmission; Fits 1965-1966 Jeep Wagoneer, with Borg-Warner T89C Transmission; Fits 1965-1972 Ford F-100, with 10 Splines; with Borg-Warner T18 Transmission; Fits 1968-1972 Ford F-100, with 10 Splines; with Borg-Warner T18B Transmission; Fits 1968-1972 Ford F-250, with 10 Splines; with Borg-Warner T18 Transmission; Fits 1968-1972 Ford F-250, with 10 Splines; with Borg-Warner T18B Transmission; Fits 1968-1972 Ford F-350, with 10 Splines; with Borg-Warner T18 Transmission; Fits 1968-1972 Ford F-350, with 10 Splines; with Borg-Warner T18B Transmission.

Quality Assurance

National has supplied premium sealing solutions for more than 75 years and continues to develop sealing products for current and legacy vehicle service needs. National 450308 reflects that focus on dimensional accuracy and transmission sealing performance.