{"product_id":"lock-nut-drive-gear-to-u-joint-for-mercruiser-sterndrive-replaces-mercury-11-22339-sierra-18-3713","title":"Sierra Lock Nut 5\/8\"-18, Stainless Steel, Replaces Mercury Marine 11-22339","description":"\u003cp\u003eThis Sierra lock nut, part number 18-3713, is a stainless steel fastener sized 5\/8\"-18 with a Unified National Coarse (UNC) thread, right-hand thread direction, and full thread coverage. It is built with a flange screw head style and a machined finish in black, giving it a corrosion-resistant, durable surface suited to marine environments where saltwater exposure and vibration are common concerns. As a lock nut, its primary function is to stay securely fastened under vibration and load, making it well suited for gearcase and drive component assembly where a fastener backing off could lead to a loose or failed connection. It is used in Mercruiser gearcase and drive applications and is a direct equivalent for Mercury Marine part number 11-22339, allowing it to be installed as a replacement for that OEM part. The stainless steel construction resists rust and corrosion better than standard plated steel hardware, which is important for any fastener used below the waterline or in a wet engine compartment. Each lock nut ships as a single piece for straightforward one-for-one replacement during service or rebuild work.\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 18-3713\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Lock Nut\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Size:\u003c\/strong\u003e 5\/8 inch - 18\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Type:\u003c\/strong\u003e Unified National Coarse (UNC)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Class:\u003c\/strong\u003e Coarse\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Coverage:\u003c\/strong\u003e Fully Threaded\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Style:\u003c\/strong\u003e Right Hand\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFastener Type:\u003c\/strong\u003e Lock\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eScrew Head Style:\u003c\/strong\u003e Flange\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Stainless Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExterior Finish:\u003c\/strong\u003e Machined\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e Black\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.04 pounds\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eUsed in Mercruiser gearcase and drive applications.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eMercury Marine 11-22339\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the thread size on the Sierra 18-3713 lock nut?\u003c\/strong\u003e The Sierra 18-3713 lock nut has a 5\/8 inch - 18 thread size with a Unified National Coarse (UNC), right-hand thread.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes this lock nut cross-reference to a Mercury Marine part number?\u003c\/strong\u003e Yes, Sierra 18-3713 is the equivalent to Mercury Marine part number 11-22339.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the 18-3713 lock nut made from?\u003c\/strong\u003e It is made from stainless steel with a machined finish in black, which resists corrosion in marine environments.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat does this part get used for?\u003c\/strong\u003e The 18-3713 lock nut is used in Mercruiser gearcase and drive component assemblies to keep fasteners secure under vibration and load.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many lock nuts come in a package?\u003c\/strong\u003e The Sierra 18-3713 lock nut is sold as a single piece, one nut per unit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-3713 a full-thread or partial-thread nut?\u003c\/strong\u003e It is fully threaded along its entire length, with a coarse UNC thread class.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat style of head does this lock nut have?\u003c\/strong\u003e The 18-3713 uses a flange screw head style, which provides a wider bearing surface than a standard hex nut.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a genuine Sierra part or an aftermarket copy?\u003c\/strong\u003e Sierra 18-3713 is a Sierra-branded part manufactured to equal or exceed OEM specifications, offered as a replacement for Mercury Marine 11-22339.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-3713 lock nut weigh?\u003c\/strong\u003e The Sierra 18-3713 lock nut weighs 0.04 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use this lock nut to replace a worn or damaged OEM nut on my gearcase?\u003c\/strong\u003e Yes, Sierra 18-3713 is designed as a direct replacement for Mercury Marine 11-22339 in gearcase and drive applications.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988162195675,"sku":"SIE-18-3713","price":5.1,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-3713_lg__25482.1558126447.500.750.jpg?v=1785189053","url":"https:\/\/www.goodvibesmarina.com\/products\/lock-nut-drive-gear-to-u-joint-for-mercruiser-sterndrive-replaces-mercury-11-22339-sierra-18-3713","provider":"Good Vibes Marina","version":"1.0","type":"link"}