{"product_id":"sierra-18-2945-9-marine-drain-screw-gasket-2-pack-fits-3-8-16-drain-fill-screw-replaces-mercury-mercruiser-12-19183-12-20260","title":"Sierra 18-2945-9 Drain Screw Gasket for 3\/8-16 Drain and Fill Screws, Replaces 307552, Pack of 2","description":"\u003cp\u003eThe Sierra 18-2945-9 Drain Screw Gasket is a replacement gasket sized for the 3\/8-16 drain and fill screw found on most lower units and sea water pumps, including the drain\/fill screw used on all MerCruiser sterndrives and most Mercury\/Mariner outboards. It is sold as a pack of 2 gaskets, giving you a matched set for a complete drain\/fill screw service without needing to source individual pieces separately.\u003c\/p\u003e\u003cp\u003eBuilt from stainless steel with a machined finish, this gasket is designed to create a reliable seal against water and lubricant leakage at the drain screw location, helping protect the lower unit or sea water pump from moisture intrusion and gear lube loss. Because the fit is specific to the 3\/8-16 drain screw size, it is important to confirm your screw and housing match this specification before ordering.\u003c\/p\u003e\u003cp\u003eThis gasket carries the Sierra part number 18-2945-9 and directly replaces the original equipment gasket bearing the number 307552, so it is a straightforward drop-in replacement during routine gear lube changes or drain screw servicing.\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 18-2945-9\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Quantity:\u003c\/strong\u003e Pack of 2\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Stainless Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinish:\u003c\/strong\u003e Machined Stainless Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFastener Size:\u003c\/strong\u003e 3\/8-16\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutside Diameter:\u003c\/strong\u003e 4 Inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eItem Dimensions:\u003c\/strong\u003e 4 x 4 x 1 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible Groove Diameter:\u003c\/strong\u003e 0.38 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 808282164324\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eUsed with the 3\/8-16 drain\/fill screw found on all MerCruiser sterndrives and most Mercury\/Mariner outboards\u003c\/li\u003e\n\u003cli\u003eFits most lower units and sea water pumps\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e307552\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat size drain screw does the Sierra 18-2945-9 gasket fit?\u003c\/strong\u003e The Sierra 18-2945-9 Drain Screw Gasket is sized for a 3\/8-16 drain and fill screw, the size found on all MerCruiser sterndrives and most Mercury\/Mariner outboards.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many gaskets come in a pack?\u003c\/strong\u003e This listing is for the Sierra 18-2945-9 gasket sold as a pack of 2, giving you a matched pair for a drain and fill screw service.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part number does this gasket replace?\u003c\/strong\u003e Part number 18-2945-9 replaces OEM number 307552.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the 18-2945-9 gasket made from?\u003c\/strong\u003e Stainless steel with a machined finish, chosen for corrosion resistance in marine drain and fill screw applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill this gasket fit my lower unit or sea water pump?\u003c\/strong\u003e Yes, as long as the drain or fill screw uses the 3\/8-16 thread size, since the Sierra 18-2945-9 gasket is designed to fit most lower units and sea water pumps with that screw size.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-2945-9 gasket compatible with MerCruiser sterndrives?\u003c\/strong\u003e It is compatible with all MerCruiser sterndrives that use the 3\/8-16 drain\/fill screw, along with most Mercury\/Mariner outboards.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow do I install the drain screw gasket?\u003c\/strong\u003e Remove the old drain or fill screw and gasket, place a new Sierra 18-2945-9 gasket on the screw, and reinstall the screw into the lower unit or sea water pump housing to seal the drain point.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the outer dimensions of this gasket?\u003c\/strong\u003e The Sierra 18-2945-9 gasket has an outside diameter of 4 inches and item dimensions of 4 x 4 x 1 inches, with a compatible groove diameter of 0.38 inches.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does this part weigh?\u003c\/strong\u003e The Sierra 18-2945-9 Drain Screw Gasket pack weighs 0.01 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a genuine Sierra part or an aftermarket copy?\u003c\/strong\u003e It is a Sierra branded part, number 18-2945-9, manufactured to meet or exceed the specification of the original drain screw gasket it replaces.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use this gasket on Mercury or Mariner outboards?\u003c\/strong\u003e Yes, the 3\/8-16 drain\/fill screw gasket configuration used on the Sierra 18-2945-9 fits most Mercury and Mariner outboards.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order this part?\u003c\/strong\u003e Ordering part number 18-2945-9 gets you a pack of 2 stainless steel drain screw gaskets, sized for a 3\/8-16 drain or fill screw.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988135358683,"sku":"SIE-18-2945-9","price":1.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-2945-9__72257.1737822229.500.750.jpg?v=1785188520","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-2945-9-marine-drain-screw-gasket-2-pack-fits-3-8-16-drain-fill-screw-replaces-mercury-mercruiser-12-19183-12-20260","provider":"Good Vibes Marina","version":"1.0","type":"link"}