{"product_id":"national-3909-engine-crankshaft-seal","title":"National 3909 Engine Crankshaft Seal - Rear","description":"\u003ch2\u003eOverview of National 3909 Engine Crankshaft Seal\u003c\/h2\u003e\u003cp\u003eThe National 3909 engine crankshaft seal is designed to provide reliable sealing performance for various vehicle models including Ford, Jaguar, Lincoln, and Aston Martin. Engineered with fluoro-elastomer material and a counter-clockwise spiral lip design, this oil seal ensures effective protection against oil leaks and contamination.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eInside diameter: 3.625 inches (92.08 mm)\u003c\/li\u003e\n\u003cli\u003eOutside diameter: 4.256 inches (108.1 mm)\u003c\/li\u003e\n\u003cli\u003eThickness\/width: 0.390 inches (9.91 mm)\u003c\/li\u003e\n\u003cli\u003eMaterial: Durable fluoro-elastomer for heat and chemical resistance\u003c\/li\u003e\n\u003cli\u003eHelix type: Counter-clockwise spiral lip design for enhanced sealing\u003c\/li\u003e\n\u003cli\u003eHousing bore compatibility: 4.240 inches (107.7 mm)\u003c\/li\u003e\n\u003cli\u003ePart number: 3909, Series 3000 oil seal\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eTechnical Details and Design Features\u003c\/h2\u003e\u003cp\u003eThe National 3909 crankshaft seal is part of the Series 3000 line, known for its precision-engineered sealing components. Constructed from fluoro-elastomer, this seal offers excellent resistance to high temperatures, oils, and automotive fluids, making it suitable for demanding engine environments. The counter-clockwise spiral lip design improves sealing efficiency by directing contaminants away from the shaft, reducing wear and extending service life. With an inside diameter of 3.625 inches and an outside diameter of 4.256 inches, it fits shafts and housings with corresponding dimensions, ensuring a secure and leak-free installation.\u003c\/p\u003e\u003ch2\u003eCompatible Vehicles and Applications\u003c\/h2\u003e\u003cp\u003eThis engine crankshaft seal is compatible with a range of vehicles, including models from Ford such as the F-150, Explorer, Mustang, and Crown Victoria, as well as Lincoln, Mercury, Mazda, Jaguar, and Aston Martin models like the DB7, DB9, and V12 Vantage. It is designed to replace OEM seals in these vehicles, providing a reliable solution for engine oil sealing needs.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003ePrevents oil leaks from the crankshaft area\u003c\/li\u003e\n\u003cli\u003eProtects engine components from dirt and debris ingress\u003c\/li\u003e\n\u003cli\u003eMaintains engine oil pressure and cleanliness\u003c\/li\u003e\n\u003cli\u003eReduces risk of engine damage due to seal failure\u003c\/li\u003e\n\u003cli\u003eAddresses wear and tear from prolonged engine use\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes and Tips\u003c\/h2\u003e\u003cp\u003eWhen installing the National 3909 crankshaft seal, ensure the shaft and housing bore are clean and free of debris. Verify the seal orientation matches the counter-clockwise spiral lip design to optimize sealing performance. Use appropriate tools to avoid damaging the seal during installation. Lubricate the seal lip lightly with engine oil before fitting to reduce initial wear. Confirm the seal dimensions match the shaft and housing specifications for a proper fit.\u003c\/p\u003e\u003ch2\u003eQuality Assurance and Warranty\u003c\/h2\u003e\u003cp\u003eNational's 3909 crankshaft seal is manufactured to meet industry standards for durability and performance. The use of fluoro-elastomer material and precision design ensures consistent sealing under typical engine operating conditions. While specific warranty details are not provided, National products generally adhere to quality control processes to support reliable automotive maintenance and repair.\u003c\/p\u003e","brand":"National","offers":[{"title":"Default Title","offer_id":43448189616309,"sku":"BCZK-3909","price":35.77,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/NS_3909_Fro_1edf4a68-c9f1-4b0a-8e2c-e822ff0a1256.jpg?v=1774734516","url":"https:\/\/www.partcatalog.com\/products\/national-3909-engine-crankshaft-seal","provider":"PartCatalog","version":"1.0","type":"link"}