National 330663 Automatic Transmission Extension Housing Seal

Automatic Transmission Extension Housing Seal

The National 330663 automatic transmission extension housing seal is built for applications that require a precise seal at the transmission tail housing. With a nitrile construction and measured dimensions of 1.375 in. shaft diameter, 1.878 in. outside diameter, and 0.312 in. width, it is sized for accurate sealing performance in Chrysler A466 automatic transmission applications.

Compatible With Chrysler 300, Imperial, New Yorker, Newport, Town & Country, Dodge Dart, and Dodge Lancer applications listed below, this National 330663 seal supports restoration and service work on classic Chrysler A466 3-speed automatic transmissions.

• Inside diameter: 1.375 in. / 34.930 mm
• Outside diameter: 1.878 in. / 47.700 mm
• Housing bore: 1.874 in. / 47.600 mm
• Width: 0.312 in. / 7.920 mm
• Material: Nitrile
• Part description: Oil seal
• Series: 330000
• Type: 33

Fitment Details

• Fits 1956-1961 Chrysler 300, N/A — For use with Chrysler A466 automatic transmissions.
• Fits 1956-1961 Chrysler Imperial, N/A — For use with Chrysler A466 automatic transmissions.
• Fits 1957-1961 Chrysler New Yorker, N/A — For use with Chrysler A466 automatic transmissions.
• Fits 1961 Chrysler Newport, N/A — For use with Chrysler A466 automatic transmissions.
• Fits 1957-1961 Chrysler Town & Country, N/A — Fits Chrysler A466 3-speed automatic transmissions.
• Fits 1960-1961 Dodge Dart, N/A — For use with Chrysler A466 automatic transmissions.
• Fits 1961 Dodge Lancer, N/A — For use with Chrysler A466 automatic transmissions.
• Fits 1957-1960 Chrysler Newport, N/A — Fits Chrysler A466 3-speed automatic transmissions.
• Fits 1957-1959 Dodge Lancer, N/A — Fits Chrysler A466 3-speed automatic transmissions.

What This Seal Helps Address

• Transmission fluid seepage at the extension housing
• Leakage around the output shaft area
• Seal wear from age, heat, and fluid exposure
• Service issues during Chrysler A466 transmission rebuilds
• Replacement needs for classic Chrysler and Dodge automatic transmission maintenance

Installation Notes and Tips

Verify shaft diameter, housing bore, and width before installation to confirm the seal matches the transmission case dimensions. Clean the housing bore and shaft surface thoroughly, and inspect for scoring or wear that could affect sealing performance. This part cross-references BBB Industries (e.g., 13512, 13535) for the same application.

Quality Assurance

National has supplied sealing solutions for more than 75 years and continues to develop sealing components for current and legacy vehicle applications. Part number 330663 is part of the National 330000 series and is engineered for dimensional consistency in transmission service work.