National 4072N Automatic Transmission Torque Converter Seal

National 4072N Automatic Transmission Torque Converter Seal

National 4072N is an automatic transmission torque converter seal built for a precise sealing fit in a wide range of GM applications. It uses polyacrylate material and a clockwise-spiral lip design to help maintain sealing performance in demanding transmission environments.

Key Features

• Polyacrylate construction for transmission sealing applications
• Clockwise-spiral lip design for controlled sealing contact
• Redi-Coat finish for easier installation and sealing surface preparation
• Series 4000 oil seal design
• Dimensions: 1.787 in. shaft inside diameter, 3.238 in. outside diameter, 0.335 in. width
• National sealing technology backed by more than 75 years of industry experience

Product Details

This automatic transmission torque converter seal is engineered for vehicles using GM 3T40, 4T40-E, 4T45-E, 4T60, 4T60-E, 4T65-E, THM125, THM125C, THM440-T4, and related transmission applications listed in the fitment data. It is a direct-fit sealing component for service work on Chevrolet Cavalier, Chevrolet Malibu, Pontiac Grand Am, Pontiac Grand Prix, Saturn Vue, Buick Century, and other covered models. The National 4072N part number is also referenced in aftermarket catalogs under several cross-reference numbers for the same application.

This part cross-references ATP XO-4 and BBB Industries 17849 for the same application.

Common Problems This Seal Can Address

• Transmission fluid leakage at the torque converter seal area
• Seepage caused by worn or hardened original sealing material
• Loss of sealing integrity during transmission service or rebuild
• Fluid contamination around the front of the transmission case
• Service issues on GM automatic transmissions with matching seal dimensions

Installation Notes and Tips

• Verify transmission code and seal dimensions before installation.
• Inspect the converter hub, pump bore, and sealing surface for wear or scoring.
• Clean the housing bore thoroughly so the Redi-Coat surface can seat properly.
• Use correct seal installation tools to avoid damaging the lip or case bore.
• Confirm the application against the vehicle’s transmission type, especially on Chevrolet HHR, Impala, Cobalt, Malibu, Pontiac G5, Pontiac G6, and Saturn Vue models with specific GM transmission variants.

Quality Assurance

National has supplied premium sealing solutions for more than 75 years and continues to develop sealing components for modern vehicles. The 4072N reflects that focus with a transmission-specific design and published dimensional data for accurate service selection.