{"product_id":"national-340847-automatic-transmission-manual-shaft-seal","title":"National 340847 Automatic Transmission Manual Shaft Seal","description":"\u003ch2\u003eOverview of National 340847 Automatic Transmission Manual Shaft Seal\u003c\/h2\u003e\u003cp\u003eThe National 340847 automatic transmission manual shaft seal is engineered for reliable sealing performance in heavy-duty vehicles. Designed specifically for Chevrolet, GMC, and Hummer models, this oil seal helps maintain transmission integrity by preventing fluid leaks around the manual shaft.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eInside diameter: 0.500 inch (12.7 mm)\u003c\/li\u003e\n\u003cli\u003eOutside diameter: 0.756 inch (19.2 mm)\u003c\/li\u003e\n\u003cli\u003eThickness\/width: 0.125 inch (3.18 mm)\u003c\/li\u003e\n\u003cli\u003eSealing material: durable nitrile rubber\u003c\/li\u003e\n\u003cli\u003eHousing bore size: 0.750 inch (19.05 mm)\u003c\/li\u003e\n\u003cli\u003ePart number: 340847\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eTechnical Details and Material Specifications\u003c\/h2\u003e\u003cp\u003eThis National 340847 seal is constructed from nitrile, a material known for its resistance to oil, heat, and wear, making it suitable for transmission applications. The seal’s precise dimensions—0.500 inch inside diameter and 0.756 inch outside diameter—ensure a tight fit on the manual shaft and housing bore, minimizing the risk of leaks. With a thickness of 0.125 inch, the seal provides a robust barrier against contaminants while maintaining flexibility for shaft movement.\u003c\/p\u003e\u003ch2\u003eCompatible Vehicles and Applications\u003c\/h2\u003e\u003cp\u003eThis automatic transmission manual shaft seal is compatible with a range of Chevrolet, GMC, and Hummer models, including:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eChevrolet Silverado 2500 HD, 2500 HD Classic, 3500, 3500 Classic, and 3500 HD\u003c\/li\u003e\n\u003cli\u003eGMC Sierra 2500 HD, 2500 HD Classic, 3500, 3500 Classic, and 3500 HD\u003c\/li\u003e\n\u003cli\u003eHummer H1\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eIt is designed to replace worn or damaged seals in these vehicles’ automatic transmissions, helping to maintain proper fluid retention and transmission performance.\u003c\/p\u003e\u003ch2\u003eCommon Issues Addressed by the National 340847 Seal\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003ePrevents transmission fluid leaks around the manual shaft\u003c\/li\u003e\n\u003cli\u003eReduces contamination ingress that can damage transmission components\u003c\/li\u003e\n\u003cli\u003eMaintains proper hydraulic pressure within the transmission system\u003c\/li\u003e\n\u003cli\u003eMinimizes premature wear of transmission shafts and bearings\u003c\/li\u003e\n\u003cli\u003eHelps avoid costly transmission repairs due to seal failure\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eInstallation Notes and Tips\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eEnsure the shaft and housing bore are clean and free of debris before installation\u003c\/li\u003e\n\u003cli\u003eLubricate the seal lip with transmission fluid or compatible lubricant to ease installation\u003c\/li\u003e\n\u003cli\u003eUse proper tools to press the seal evenly into the housing bore without distortion\u003c\/li\u003e\n\u003cli\u003eVerify correct orientation of the seal to ensure optimal sealing performance\u003c\/li\u003e\n\u003cli\u003eInspect the shaft for wear or damage before installing the new seal\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eQuality Assurance and Warranty Information\u003c\/h2\u003e\u003cp\u003eNational transmission seals are manufactured to meet industry standards for durability and performance. The 340847 seal undergoes rigorous quality control to ensure dimensional accuracy and material integrity. While specific warranty terms may vary, National typically offers coverage against manufacturing defects to provide confidence in the product’s reliability.\u003c\/p\u003e","brand":"National","offers":[{"title":"Default Title","offer_id":43448296341685,"sku":"BCZK-340847","price":15.73,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0628\/1442\/1173\/files\/NS_340847_Fro.jpg?v=1774734638","url":"https:\/\/www.partcatalog.com\/products\/national-340847-automatic-transmission-manual-shaft-seal","provider":"PartCatalog","version":"1.0","type":"link"}