{"product_id":"sierra-18-2171-engine-coupler-for-gm-replaces-mercruiser-76850a2-triangular-3-bolt-coupler","title":"Sierra 18-2171 Engine Coupler, Replaces 76850A2, for GM Engines with Triangular 3-Bolt Coupler except MR\/Alpha\/Bravo","description":"\u003cp\u003eThe Sierra 18-2171 Engine Coupler is a direct replacement engine coupler built for GM engines fitted with a triangular, 3-bolt coupler design, excluding MR\/Alpha\/Bravo drive configurations. It connects the engine flywheel to the transmission or outdrive, transferring rotational torque while accommodating minor misalignment between the engine and drive unit. Correct coupler fitment is critical: installing the wrong coupler pattern can prevent proper engagement with the drive and lead to premature wear or failure.\u003c\/p\u003e\u003cp\u003eThis coupler is manufactured from metal with a machined black finish, built to meet or exceed the quality of the original equipment part it replaces. It is a single-piece unit that cross-references directly to six OEM Mercury\/Mercruiser part numbers, making it straightforward to identify as the correct replacement when servicing engines that use the triangular 3-bolt coupler pattern. Sierra engineers its couplers to hold up under the demands of high-horsepower marine engines operating in harsh, corrosive marine environments.\u003c\/p\u003e\u003cp\u003eUse this coupler when servicing or replacing a worn, cracked, or damaged coupler on an eligible GM engine, or when rebuilding the engine-to-drive connection during an outdrive or transmission service.\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 18-2171\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Metal\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e Black\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExterior Finish:\u003c\/strong\u003e Machined\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnector Type:\u003c\/strong\u003e Coupling\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Type:\u003c\/strong\u003e NPT\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eItem Dimensions:\u003c\/strong\u003e 5.2 x 5.1 x 4.9 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 3.63 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of Pieces:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 030999311757\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\u003cli\u003eAll GM engines except MR\/Alpha\/Bravo with a triangular, 3-bolt coupler\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e32492A2\u003c\/li\u003e\n\u003cli\u003e32492A3\u003c\/li\u003e\n\u003cli\u003e32492A5\u003c\/li\u003e\n\u003cli\u003e38965A1\u003c\/li\u003e\n\u003cli\u003e38965A2\u003c\/li\u003e\n\u003cli\u003e76850A2\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-2171 Engine Coupler fit?\u003c\/strong\u003e It fits all GM engines except MR\/Alpha\/Bravo configurations that use a triangular, 3-bolt coupler pattern. Check your existing coupler's bolt pattern before ordering to confirm compatibility.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat OEM part numbers does the 18-2171 replace?\u003c\/strong\u003e The Sierra 18-2171 replaces OEM numbers 32492A2, 32492A3, 32492A5, 38965A1, 38965A2, and 76850A2.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill this coupler work with an Alpha or Bravo outdrive?\u003c\/strong\u003e No, the 18-2171 is specifically excluded for MR, Alpha, and Bravo drive configurations; it is intended for GM engines using the triangular 3-bolt coupler pattern instead.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the dimensions of the 18-2171 coupler?\u003c\/strong\u003e The coupler measures 5.2 x 5.1 x 4.9 inches.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Sierra 18-2171 weigh?\u003c\/strong\u003e It weighs 3.63 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the engine coupler made from?\u003c\/strong\u003e The 18-2171 is made from metal with a machined black finish for durability in marine service.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the Sierra 18-2171 a genuine OEM part or an aftermarket replacement?\u003c\/strong\u003e It is an aftermarket coupler manufactured by Sierra to meet or exceed the specifications of the original equipment coupler it replaces, including 76850A2 and the other listed cross-references.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many pieces come in the package?\u003c\/strong\u003e The 18-2171 ships as a single one-piece coupler unit.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow is the 3-bolt coupler pattern different from other coupler types?\u003c\/strong\u003e The 18-2171 uses a triangular 3-bolt bolt pattern, which is a different mounting configuration than couplers used on MR\/Alpha\/Bravo drives, so the two are not interchangeable.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-2171?\u003c\/strong\u003e The UPC for the Sierra 18-2171 Engine Coupler is 030999311757.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhen would I need to replace the engine coupler?\u003c\/strong\u003e The 18-2171 should be replaced if the existing coupler on a compatible GM engine is worn, cracked, or damaged, or during a transmission or outdrive service where the coupler is inspected.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988105539803,"sku":"SIE-18-2171","price":248.67,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-2171_lg__02766.1558121284.500.750.jpg?v=1785188134","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-2171-engine-coupler-for-gm-replaces-mercruiser-76850a2-triangular-3-bolt-coupler","provider":"Good Vibes Marina","version":"1.0","type":"link"}