{"product_id":"sierra-18-0515-oil-seal-replaces-mercury-36-30530-fits-mercury-4-hp-40-outboard-powerhead-crankshaft","title":"Sierra 18-0515 Oil Seal, Replaces Mercury 26-30530, for Outboard Powerhead Crankshaft","description":"\u003cp\u003eThe Sierra 18-0515 is a round oil seal designed for Mercury outboard powerhead crankshaft applications. It seals the crankshaft bore to keep lubricating oil contained within the powerhead while preventing water and contaminants from entering, protecting internal engine components from leaks and premature wear. The seal is finished in white and is built to Sierra's standard fit and function for this position.\u003c\/p\u003e\u003cp\u003eThis seal carries precise dimensions of 0.540 inch shaft size, 1.004 inch outside diameter, and 0.303 inch width, matching the profile of the Mercury OEM oil seal it replaces. Because oil seals in this size range are used across multiple engine positions, always confirm these three measurements against your old seal or your engine's parts diagram before ordering to ensure a correct fit.\u003c\/p\u003e\u003cp\u003eSierra International supplies replacement parts for marine engines, and the 18-0515 is cataloged specifically as a Mercury outboard powerhead crankshaft seal, making it a straightforward like-for-like replacement for the corresponding Mercury OEM part. It is sold as a single seal.\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 18-0515\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e 26-30530\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShaft Size:\u003c\/strong\u003e 0.540 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutside Diameter:\u003c\/strong\u003e 1.004 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 0.303 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShape:\u003c\/strong\u003e Round\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.01 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999874276\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplication:\u003c\/strong\u003e Mercury outboard powerhead crankshaft seal\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eDesigned for Mercury outboard powerhead crankshaft applications requiring an oil seal with a 0.540 inch shaft size, 1.004 inch outside diameter, and 0.303 inch width. Verify these dimensions against your existing seal before purchase.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e26-30530\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0515 oil seal fit?\u003c\/strong\u003e The Sierra 18-0515 is cataloged for Mercury outboard powerhead crankshaft applications, sealing the crankshaft bore to retain lubricating oil and keep out contaminants.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0515 the same as Mercury 26-30530?\u003c\/strong\u003e Yes, the 18-0515 is Sierra's direct replacement for Mercury OEM oil seal 26-30530, matching its shaft size, outside diameter, and width.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the 18-0515 oil seal?\u003c\/strong\u003e This seal measures 0.540 inches at the shaft, 1.004 inches on the outside diameter, and 0.303 inches wide.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the Sierra 18-0515 oil seal?\u003c\/strong\u003e It is white, as manufactured by Sierra International.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-0515 oil seal weigh?\u003c\/strong\u003e The Sierra 18-0515 weighs 0.01 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I know if this seal will fit my engine?\u003c\/strong\u003e Compare the shaft size, outside diameter, and width of your existing seal to the 18-0515 specs of 0.540 inches, 1.004 inches, and 0.303 inches respectively, since seals in this size range can be used in more than one engine position.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0515 a genuine Mercury part or aftermarket?\u003c\/strong\u003e The 18-0515 is a Sierra-manufactured aftermarket seal built to replace Mercury OEM part 26-30530, not a genuine Mercury-branded component.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat shape is the 18-0515 seal?\u003c\/strong\u003e The Sierra 18-0515 oil seal is round in shape.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat comes in the package with the 18-0515?\u003c\/strong\u003e The package includes one Sierra 18-0515 oil seal.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0515 oil seal?\u003c\/strong\u003e The UPC for this Sierra oil seal is 030999874276.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat category of part is the 18-0515?\u003c\/strong\u003e The 18-0515 is classified as a Mercury outboard powerhead crankshaft seal.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988075524315,"sku":"SIE-18-0515","price":9.45,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0515_lg__79364.1558118539.500.750.jpg?v=1785188113","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-0515-oil-seal-replaces-mercury-36-30530-fits-mercury-4-hp-40-outboard-powerhead-crankshaft","provider":"Good Vibes Marina","version":"1.0","type":"link"}