{"product_id":"sierra-18-0577-carrier-assembly-oil-seal-replaces-mercruiser-66081a2-fits-alpha-one-gen-ii-upper-gear-housing","title":"Sierra 18-0577 Carrier Oil Seal Assembly, Replaces Mercruiser 66081A2, for Alpha One and Gen II Stern Drives","description":"\u003cp\u003eThe Sierra 18-0577 Carrier Oil Seal Assembly is a replacement seal for the upper gear housing carrier on MerCruiser stern drive units. It fits the 888\/228\/250\/260 series, the R and MR designations, Alpha One (including Alpha One SS and the counter-rotating CR versions), and Alpha One Gen II drives (including the CR versions). This seal assembly is a direct cross to Mercruiser 66081A2, 35993A1, 66081A1, and 66081A4, as well as GLM 28370 and Mallory 9-78100, so it can be used to service drives originally fitted with any of those parts.\u003c\/p\u003e\u003cp\u003eThe carrier oil seal keeps gear lube contained within the upper gear housing while preventing water intrusion at the drive shaft carrier, protecting the gear set from contamination and low-lubricant wear. It is typically installed as part of a routine upper gear housing seal kit service or whenever the carrier bearing\/seal area is opened up for repair. Sierra manufactures this part to meet or exceed the specification of the original equipment it replaces, and it is backed by Sierra's standard customer satisfaction warranty.\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 18-0577\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Carrier Oil Seal Assembly\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Mercruiser Upper Gear Housing Seal Kits\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.2 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnit Count:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999973986\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGTIN:\u003c\/strong\u003e 00030999973986\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross-Reference:\u003c\/strong\u003e GLM 28370, Mallory 9-78100, Mercruiser 66081A2, 35993A1, 66081A1, 66081A4\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\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\u003eGLM 28370\u003c\/li\u003e\n\u003cli\u003eMallory 9-78100\u003c\/li\u003e\n\u003cli\u003eMercruiser 66081A2\u003c\/li\u003e\n\u003cli\u003eMercruiser 35993A1\u003c\/li\u003e\n\u003cli\u003eMercruiser 66081A1\u003c\/li\u003e\n\u003cli\u003eMercruiser 66081A4\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0577 Carrier Oil Seal Assembly fit?\u003c\/strong\u003e It fits MerCruiser stern drive units including the 888\/228\/250\/260 series (1977-1982), the R (1983) and MR (1984-1990) designations, Alpha One and Alpha One SS (1986-1989), and Alpha One Gen II drives (1991-2010), including the counter-rotating (CR) versions.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0577 seal a genuine OEM part or aftermarket?\u003c\/strong\u003e Sierra 18-0577 is a Sierra-manufactured replacement part, built to meet or exceed the original equipment specification for the Mercruiser carrier oil seal it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part numbers does Sierra 18-0577 cross to?\u003c\/strong\u003e This carrier oil seal assembly is interchangeable with Mercruiser 66081A2, 35993A1, 66081A1, and 66081A4, as well as GLM 28370 and Mallory 9-78100.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0577 fit both Alpha One and Alpha One Gen II drives?\u003c\/strong\u003e Yes, the 18-0577 carrier oil seal is used across Alpha One (1984-1990), Alpha One SS (1986-1989), and Alpha One Gen II (1991-2010) MerCruiser stern drives, including the CR variants.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0577 weigh?\u003c\/strong\u003e The Sierra 18-0577 Carrier Oil Seal Assembly weighs 0.2 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many pieces come in the 18-0577 package?\u003c\/strong\u003e The Sierra 18-0577 ships as a single carrier oil seal assembly, unit count of 1.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the function of the carrier oil seal on a stern drive?\u003c\/strong\u003e The carrier oil seal seated in the upper gear housing keeps gear lubricant contained around the drive shaft carrier while blocking water intrusion, protecting the gear set from contamination and lubricant loss.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen should the carrier oil seal be replaced?\u003c\/strong\u003e The 18-0577 carrier oil seal is typically replaced during a upper gear housing seal service, or any time the carrier bearing and seal area is opened up for repair or found to be leaking gear lube.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 18-0577 fit the MerCruiser 888\/228\/250\/260 models?\u003c\/strong\u003e Yes, the Sierra 18-0577 is listed for the MerCruiser 888\/228\/250\/260 series produced 1977-1982.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-0577 covered by a warranty?\u003c\/strong\u003e Sierra 18-0577, like other Sierra parts, is covered under Sierra's standard customer satisfaction warranty.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988078866651,"sku":"SIE-18-0577","price":53.41,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0577_lg__38802.1558120940.500.750.jpg?v=1785188852","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-0577-carrier-assembly-oil-seal-replaces-mercruiser-66081a2-fits-alpha-one-gen-ii-upper-gear-housing","provider":"Good Vibes Marina","version":"1.0","type":"link"}