{"product_id":"sierra-18-2011-marine-oil-seal-replaces-mercury-26-90562-mercruiser-lower-gear-housing-water-pump-base-seal","title":"Sierra 18-2011 Oil Seal for MerCruiser 60\/80\/90 Gear Housing (1965-1972), Replaces Mercury Marine 26-90562","description":"\u003cp\u003eThe Sierra 18-2011 is a lower gear housing oil seal built for MerCruiser 60\/80\/90 model stern drives produced from 1965 to 1972. It is a precision-machined replacement seal used during gear housing service, sealing the housing against water intrusion and lubricant loss at the shaft. The seal cross-references directly to Mercury Marine part number 26-90562, making it a straightforward drop-in replacement for boaters and marine technicians rebuilding or servicing the lower unit on this model line.\u003c\/p\u003e\u003cp\u003eThe 18-2011 measures 1.250 inches in outer diameter, has a shaft size of 0.750 inches, and a width of 0.312 inches, with a machined exterior finish. It is a compact, lightweight component at 0.02 pounds, sized to fit within the gear housing seal carrier alongside the other components (such as the O-ring and bearing carrier) used in MerCruiser 60\/80\/90 gear housing seal service.\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 18-2011\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e MerCruiser Lower Gear Housing Seal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOuter Diameter:\u003c\/strong\u003e 1.250 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShaft Size:\u003c\/strong\u003e 0.750 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 0.312 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.02 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExterior Finish:\u003c\/strong\u003e Machined\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999309570\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMerCruiser 60 \/ 80 \/ 90 model gear housings, 1965-1972\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercury Marine 26-90562\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-2011 oil seal fit?\u003c\/strong\u003e The 18-2011 is designed for MerCruiser 60\/80\/90 model lower gear housings built from 1965 to 1972.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-2011 the same as Mercury Marine 26-90562?\u003c\/strong\u003e Yes, the 18-2011 cross-references directly to Mercury Marine part number 26-90562.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of this seal?\u003c\/strong\u003e The 18-2011 measures 1.250 inches in outer diameter, 0.750 inch shaft size, and 0.312 inch width.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-2011 oil seal weigh?\u003c\/strong\u003e 0.02 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the exterior finish on this seal?\u003c\/strong\u003e The Sierra 18-2011 has a machined exterior finish.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a genuine Mercury OEM part or an aftermarket replacement?\u003c\/strong\u003e The 18-2011 is manufactured by Sierra as an aftermarket seal engineered to the Mercury Marine 26-90562 specification, rather than a Mercury-branded part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-2011?\u003c\/strong\u003e 030999309570.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere does this seal fit within the gear housing?\u003c\/strong\u003e In the MerCruiser 60\/80\/90 gear housing seal chart, the 18-2011 is listed as the Seal component alongside the O-ring and bearing carrier used for that model and year range.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-2011 fit later MerCruiser models like the Alpha One?\u003c\/strong\u003e No, the 18-2011 is listed specifically for the 60\/80\/90 model gear housings covering 1965-1972; later MerCruiser drive lines use different Sierra seal part numbers.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat size shaft does the 18-2011 seal accept?\u003c\/strong\u003e A 0.750 inch shaft, per the seal's listed shaft size.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included with this part?\u003c\/strong\u003e The 18-2011 is sold as a single oil seal, not a full gear housing seal kit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the 18-2011 be cross-referenced by its Mercury Marine number?\u003c\/strong\u003e Yes, searching Mercury Marine 26-90562 will return the Sierra 18-2011 as its cross-referenced equivalent.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988090302683,"sku":"SIE-18-2011","price":12.77,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/18-2011__04532.1722501864.500.750.jpg?v=1785189002","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-2011-marine-oil-seal-replaces-mercury-26-90562-mercruiser-lower-gear-housing-water-pump-base-seal","provider":"Good Vibes Marina","version":"1.0","type":"link"}