{"product_id":"sierra-18-0559-marine-oil-seal-replaces-omc-332585-evinrude-johnson-outboard-prop-driveshaft-seal-0-285-id-x-0-357-od-x-0-940","title":"Sierra 18-0559 Outboard Prop Shaft Oil Seal, Replaces OMC 332585","description":"\u003cp\u003eThe Sierra 18-0559 is an oil seal built for outboard prop shaft and driveshaft applications. It keeps water out and lubricant in around the rotating shaft, protecting the lower unit gearcase from water intrusion and preventing lubricant loss that can lead to premature gear and bearing wear. The seal is sized to a 0.357 inch outside diameter, a 0.285 inch shaft size, and a 0.940 inch width, so it seats precisely in the housing bore it is designed for and rides correctly against the shaft without leaking.\u003c\/p\u003e\u003cp\u003eThis part is a direct equivalent to OEM OMC 332585, giving boat owners and marine technicians a way to source the correct seal without going through OMC directly. It is a small, precise component, so correct orientation and a light coat of marine grease during installation help it seat fully and seal properly on the first try. Because it is a wear item exposed to constant water contact and shaft rotation, it is a common preventive-maintenance replacement during lower unit service, gearcase rebuilds, or whenever water is found in the gear lubricant.\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 18-0559\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutside Diameter:\u003c\/strong\u003e 0.357 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShaft Size:\u003c\/strong\u003e 0.285 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth:\u003c\/strong\u003e 0.940 inches\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 030999874603\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Cross Reference:\u003c\/strong\u003e OMC 332585\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eDesigned for outboard prop shaft and driveshaft seal applications.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eOMC 332585\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-0559 oil seal replace?\u003c\/strong\u003e The Sierra 18-0559 is a direct cross reference to OEM OMC 332585, so it installs as a like-for-like replacement for that part number.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat size is the Sierra 18-0559 oil seal?\u003c\/strong\u003e It measures 0.357 inches outside diameter, 0.285 inches shaft size, and 0.940 inches in width.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-0559 an OEM part or an aftermarket equivalent?\u003c\/strong\u003e It is a Sierra-branded aftermarket seal manufactured as a direct equivalent to OEM OMC 332585, not an OMC-branded part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat application is the 18-0559 seal used for?\u003c\/strong\u003e This oil seal is designed for outboard prop shaft and driveshaft sealing, keeping water out of the gearcase and lubricant in around the rotating shaft.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-0559 oil seal weigh?\u003c\/strong\u003e The seal weighs 0.01 pounds, consistent with its small, precise seal profile.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when you order the 18-0559?\u003c\/strong\u003e Ordering the Sierra 18-0559 gets you a single oil seal sized to a 0.357 inch O.D., 0.285 inch shaft size, and 0.940 inch width; no gaskets or hardware are included.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy would I need to replace this seal?\u003c\/strong\u003e If water shows up in the gearcase lubricant or the lower unit is being rebuilt, the prop shaft seal is a common wear item to replace, and the 18-0559 is sized for that job.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-0559 come with an OEM number I can cross-reference?\u003c\/strong\u003e Yes, its OEM cross reference is OMC 332585, which can be used to confirm it is the correct seal for your application.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow is the Sierra 18-0559 installed?\u003c\/strong\u003e The seal should be pressed squarely into its housing bore with the correct orientation and a light coat of marine grease on the lip to help it seat fully against the 0.285 inch shaft without leaking.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-0559 oil seal?\u003c\/strong\u003e The UPC for this Sierra oil seal, part number 18-0559, is 030999874603.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988078735579,"sku":"SIE-18-0559","price":2.13,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-0559_lg__33351.1558120404.500.750.jpg?v=1785188937","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-0559-marine-oil-seal-replaces-omc-332585-evinrude-johnson-outboard-prop-driveshaft-seal-0-285-id-x-0-357-od-x-0-940","provider":"Good Vibes Marina","version":"1.0","type":"link"}