{"product_id":"sierra-18-2003-oil-seal-replaces-mercury-26-64893-mercruiser-upper-gear-housing-sterndrive-seal-kit-component","title":"Sierra 18-2003 Oil Seal for MerCruiser Alpha One Upper Gear Housing, Replaces Mercury Marine 26-68493 26-823894","description":"\u003cp\u003eThe Sierra 18-2003 is an upper gear housing oil seal built for MerCruiser stern drive applications, including the Alpha One, Alpha One SS, and Alpha One Gen II family of drives. It is designed to keep gear lube contained within the upper drive housing while sealing out water intrusion, protecting the gear set and bearings from contamination and premature wear. The seal is white in color with a rectangular profile and is a lightweight, single-piece component intended for straightforward replacement during upper gear housing service or seal kit rebuilds.\u003c\/p\u003e\u003cp\u003eThis seal cross-references directly to Mercury Marine OEM part numbers 26-68493 and 26-823894, making it a drop-in equivalent for owners who prefer an aftermarket-priced option without deviating from OEM fit and function. Fitment spans a wide range of MerCruiser drive applications and model years, from early 888\/228\/250\/260 units through Alpha One Gen II (CR) drives. Because a gear housing seal is a wear item exposed to constant lubricant and water contact, replacing it whenever the upper housing is opened for service helps prevent leaks and gear lube contamination.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-2003\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShape:\u003c\/strong\u003e Rectangular\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.06 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of Origin:\u003c\/strong\u003e Taiwan\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity:\u003c\/strong\u003e 1 seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e Mercury Marine 26-68493, 26-823894\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMerCruiser 888 \/ 228 \/ 250 \/ 260, 1977-1982\u003c\/li\u003e\n\u003cli\u003eMerCruiser R, 1983 \u0026amp; up\u003c\/li\u003e\n\u003cli\u003eMerCruiser MR Alpha One, 1984-1990\u003c\/li\u003e\n\u003cli\u003eMerCruiser MR Alpha One (CR), 1984-1990\u003c\/li\u003e\n\u003cli\u003eMerCruiser Alpha One SS, 1986-1989\u003c\/li\u003e\n\u003cli\u003eMerCruiser Alpha One Gen II, 1991-1995\u003c\/li\u003e\n\u003cli\u003eMerCruiser Alpha One Gen II (CR), 1991-1995\u003c\/li\u003e\n\u003cli\u003eMerCruiser Alpha One Gen II, 1996-1997\u003c\/li\u003e\n\u003cli\u003eMerCruiser Alpha One Gen II (CR), 1996-2010\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMercury Marine 26-68493\u003c\/li\u003e\n\u003cli\u003eMercury Marine 26-823894\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat MerCruiser drives does the Sierra 18-2003 oil seal fit?\u003c\/strong\u003e The Sierra 18-2003 fits MerCruiser 888\/228\/250\/260 drives (1977-1982), MerCruiser R (1983 \u0026amp; up), MR Alpha One and MR Alpha One (CR) drives (1984-1990), Alpha One SS drives (1986-1989), and Alpha One Gen II and Alpha One Gen II (CR) drives (1991-1995, 1996-1997, and 1996-2010).\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-2003 the same as a Mercury Marine seal?\u003c\/strong\u003e Yes, the Sierra 18-2003 cross-references directly to Mercury Marine OEM oil seals 26-68493 and 26-823894, so it fits and functions the same as the genuine Mercury Marine part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color and shape is the 18-2003 seal?\u003c\/strong\u003e It is a white, rectangular-shaped seal designed for the upper gear housing of the specified MerCruiser drives.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-2003 oil seal weigh?\u003c\/strong\u003e This oil seal weighs 0.06 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere is the Sierra 18-2003 oil seal manufactured?\u003c\/strong\u003e The Sierra 18-2003 upper gear housing oil seal is manufactured in Taiwan.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-2003 a genuine Mercury Marine part or an aftermarket replacement?\u003c\/strong\u003e It is an aftermarket Sierra-brand oil seal, not a genuine Mercury Marine part, but it cross-references to Mercury Marine 26-68493 and 26-823894 for equivalent fit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-2003 seal fit the Alpha One Gen II (CR) drive?\u003c\/strong\u003e Yes, the 18-2003 fits Alpha One Gen II (CR) drives for the 1991-1995 and 1996-2010 model years.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many seals come in a package?\u003c\/strong\u003e The Sierra 18-2003 is packaged as a single oil seal per unit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-2003 fit the early MerCruiser 888\/228\/250\/260 drives?\u003c\/strong\u003e Yes, this seal fits MerCruiser 888\/228\/250\/260 drives from the 1977-1982 model years.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the OEM cross-reference number for the Sierra 18-2003?\u003c\/strong\u003e The Sierra 18-2003 cross-references to Mercury Marine 26-68493 and 26-823894.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill the 18-2003 fit an Alpha One SS drive?\u003c\/strong\u003e Yes, the Sierra 18-2003 is listed for MerCruiser Alpha One SS drives from the 1986-1989 model years.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the 18-2003 seal used for?\u003c\/strong\u003e The 18-2003 is an upper gear housing oil seal used to retain gear lubricant and keep water out of the upper drive housing on the listed MerCruiser applications.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988090269915,"sku":"SIE-18-2003","price":21.19,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-2003_lg__62920.1558121909.500.750.jpg?v=1785188676","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-2003-oil-seal-replaces-mercury-26-64893-mercruiser-upper-gear-housing-sterndrive-seal-kit-component","provider":"Good Vibes Marina","version":"1.0","type":"link"}