{"product_id":"national-4765-automatic-transmission-extension-housing-seal","title":"National 4765 Automatic Transmission Extension Housing Seal","description":"\u003ch2\u003eOverview of National 4765 Automatic Transmission Extension Housing Seal\u003c\/h2\u003e\u003cp\u003eThe National 4765 automatic transmission extension housing seal is engineered for reliable sealing performance in Ford, Lincoln, and Mercury vehicles. Designed with precision to fit models such as the Ford F-150, Explorer, Mustang, and Lincoln Town Car, this seal helps maintain transmission integrity by preventing fluid leaks.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eInside diameter options: 1.598 inch (40.590 mm)\u003c\/li\u003e\n\u003cli\u003eOutside diameter: 2.483 inch (63.070 mm)\u003c\/li\u003e\n\u003cli\u003eFlanged outside diameter: 2.747 inch (69.770 mm)\u003c\/li\u003e\n\u003cli\u003eThickness: 0.350 inch (8.890 mm)\u003c\/li\u003e\n\u003cli\u003eMaterial: Durable fluoro-elastomer with counter-clockwise spiral lip design\u003c\/li\u003e\n\u003cli\u003eRedicoat surface treatment for enhanced wear resistance\u003c\/li\u003e\n\u003cli\u003eCompatible with housing bore diameter of 2.476 inch (62.890 mm)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eDetailed Product Description and Specifications\u003c\/h2\u003e\u003cp\u003eThe National 4765 seal is part of the 4000 series and features a 79-type oil seal construction optimized for automatic transmission extension housings. Its fluoro-elastomer material offers chemical resistance and durability under high temperature and pressure conditions typical in transmission systems. The counter-clockwise spiral lip design improves sealing efficiency by directing fluid away from the shaft, reducing leakage risks. The seal’s flanged outside diameter of 2.747 inches ensures a secure fit within the housing bore of 2.476 inches, while the overall width with side lip measures 1.475 inches (37.465 mm), providing a robust sealing surface.\u003c\/p\u003e\u003ch2\u003eCompatible Vehicles and Applications\u003c\/h2\u003e\u003cp\u003eThis transmission extension housing seal is compatible with a wide range of Ford, Lincoln, and Mercury models, including but not limited to:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eFord F-150, F-250, F-350, and Expedition\u003c\/li\u003e\n\u003cli\u003eLincoln Town Car, Mark LT, Mark VIII, and LS\u003c\/li\u003e\n\u003cli\u003eMercury Mountaineer, Cougar, and Marauder\u003c\/li\u003e\n\u003cli\u003eFord Explorer, Mustang, Thunderbird, and Crown Victoria\u003c\/li\u003e\n\u003cli\u003eFord E-Series vans such as E-150, E-250, and E-350 in various configurations\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eCommon Issues Addressed by National 4765 Seal\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003ePrevents automatic transmission fluid leaks at the extension housing\u003c\/li\u003e\n\u003cli\u003eReduces contamination ingress into transmission components\u003c\/li\u003e\n\u003cli\u003eMinimizes wear on transmission shafts by maintaining proper lubrication\u003c\/li\u003e\n\u003cli\u003eHelps maintain transmission pressure and performance\u003c\/li\u003e\n\u003cli\u003ePrevents premature seal failure due to heat and chemical exposure\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes and Tips\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eEnsure the housing bore and shaft surfaces are clean and free of debris before installation\u003c\/li\u003e\n\u003cli\u003eUse appropriate tools to avoid damaging the fluoro-elastomer seal lip during installation\u003c\/li\u003e\n\u003cli\u003eVerify correct orientation of the counter-clockwise spiral lip to ensure proper sealing direction\u003c\/li\u003e\n\u003cli\u003eApply a light coating of transmission fluid to the seal lip to facilitate installation and initial lubrication\u003c\/li\u003e\n\u003cli\u003eCheck for proper fitment with the specific Ford, Lincoln, or Mercury model prior to final assembly\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eQuality Assurance and Warranty\u003c\/h2\u003e\u003cp\u003eNational 4765 seals are manufactured to meet OEM specifications for durability and performance. The fluoro-elastomer material and Redicoat treatment provide enhanced resistance to heat, chemicals, and wear. This part is backed by National’s quality standards and typically includes a limited warranty against manufacturing defects. For detailed warranty terms, refer to the product documentation or manufacturer guidelines.\u003c\/p\u003e","brand":"National","offers":[{"title":"Default Title","offer_id":43448205017269,"sku":"BCZK-4765","price":21.79,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/NS_4765_Fro.jpg?v=1774734525","url":"https:\/\/www.partcatalog.com\/products\/national-4765-automatic-transmission-extension-housing-seal","provider":"PartCatalog","version":"1.0","type":"link"}