{"product_id":"sierra-18-21751-engine-coupler-for-volvo-penta-omc-2-5l-8-2l-replaces-3853962","title":"Sierra Engine Coupler 18-21751, Replaces 3853962-3, Fits 2.5L, 3.0L, 4.3L, 5.0L, 5.7L, 7.4L, 8.2L Engines","description":"\u003cp\u003eThe Sierra 18-21751 Engine Coupler connects the engine flywheel to the drive unit on stern drive powered boats, transferring rotational power from the engine to the outdrive while allowing for the flex needed to accommodate engine and drive alignment. It is built from metal with a machined finish for durability under continuous torque loading, and is finished in white. This coupler is a direct replacement for OEM number 3853962-3, making it a straightforward swap when the original coupler wears out, cracks, or fails to properly transmit power between the engine and drive. It fits a range of stern drive engine displacements including 2.5L (1986), 3.0L (1986-90), 4.3L, 5.0L, 5.7L (1986), 7.4L (1990-98), and 8.2L (1992-93, 1998), with the 4.3L application limited to KW and KWB suffix engines only. Replacing a worn engine coupler is a common maintenance task when a boat develops vibration, clunking on shift, or difficulty engaging gear, since a deteriorated coupler can no longer properly transfer engine power to the outdrive. Each unit ships as a single piece.\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 18-21751\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 White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eExterior Finish:\u003c\/strong\u003e Machined\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Size:\u003c\/strong\u003e 3\/8 Inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Type:\u003c\/strong\u003e NPT\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConnector Type:\u003c\/strong\u003e Coupling\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 6.45 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCountry of Origin:\u003c\/strong\u003e Taiwan\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eItem Dimensions:\u003c\/strong\u003e 0.39 x 0.39 x 0.39 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of Pieces:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e2.5L (1986)\u003c\/li\u003e\n\u003cli\u003e3.0L (1986-90)\u003c\/li\u003e\n\u003cli\u003e4.3L (KW and KWB suffix only)\u003c\/li\u003e\n\u003cli\u003e5.0L\u003c\/li\u003e\n\u003cli\u003e5.7L (1986)\u003c\/li\u003e\n\u003cli\u003e7.4L (1990-98)\u003c\/li\u003e\n\u003cli\u003e8.2L (1992-93, 1998)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e3853962-3\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat does the Sierra 18-21751 engine coupler do?\u003c\/strong\u003e The Sierra 18-21751 engine coupler connects the engine flywheel to the stern drive unit, transmitting engine power to the outdrive while flexing slightly to accommodate alignment between the two.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-21751 a direct replacement for OEM part 3853962-3?\u003c\/strong\u003e Yes, Sierra 18-21751 replaces OEM number 3853962-3 and installs as a direct equivalent for that application.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the 18-21751 coupler fit?\u003c\/strong\u003e Coverage includes 2.5L (1986), 3.0L (1986-90), 4.3L (KW and KWB suffix engines only), 5.0L, 5.7L (1986), 7.4L (1990-98), and 8.2L (1992-93, 1998) stern drive engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the 4.3L application fit all 4.3L engines?\u003c\/strong\u003e No, the 4.3L fitment for the 18-21751 coupler is limited specifically to engines with the KW or KWB suffix, not all 4.3L blocks.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the 18-21751 engine coupler made from?\u003c\/strong\u003e It is made from metal with a machined finish, providing the rigidity needed to handle continuous torque transfer between engine and drive.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-21751 engine coupler weigh?\u003c\/strong\u003e The Sierra 18-21751 engine coupler weighs 6.45 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow many couplers come in a package?\u003c\/strong\u003e The Sierra 18-21751 ships as a single piece.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat color is the 18-21751 coupler?\u003c\/strong\u003e It has a white finish.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat are the signs that an engine coupler needs to be replaced?\u003c\/strong\u003e Vibration, a clunking noise when shifting into gear, or reduced power transfer to the drive are common symptoms of a worn coupler, and the 18-21751 addresses these on applicable engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere is the 18-21751 engine coupler manufactured?\u003c\/strong\u003e The country of origin for the Sierra 18-21751 engine coupler is Taiwan.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-21751 an OEM part or aftermarket?\u003c\/strong\u003e It is a Sierra aftermarket part manufactured to replace OEM number 3853962-3 for the listed engine applications.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988105048283,"sku":"SIE-18-21751","price":257.45,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/18-21751__34662.1722497925.500.750.jpg?v=1785189019","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-21751-engine-coupler-for-volvo-penta-omc-2-5l-8-2l-replaces-3853962","provider":"Good Vibes Marina","version":"1.0","type":"link"}