{"product_id":"serpentine-belt-fits-mercruiser-alpha-bravo-v6-v8-engines-replaces-57-865615q03-57-865615-003","title":"Serpentine Belt – Fits MerCruiser Alpha\/Bravo V6\/V8 Engines (Replaces 57-865615Q03, 57-865615-003)","description":"\u003csection\u003e\n\u003c!-- 🔧 Table Styles (include only once per page) --\u003e\n\u003cstyle\u003e\n  \/* Outer container allows horizontal scrolling (with iOS momentum) *\/\n  .ss-table-wrap { overflow-x:auto; -webkit-overflow-scrolling:touch; }\n\n  \/* Base table styles *\/\n  table.ss-table { width:100%; border-collapse:collapse; min-width:640px; }\n  table.ss-table th, table.ss-table td {\n    padding:10px 12px; border:1px solid #e5e7eb; text-align:left; vertical-align:top;\n  }\n\n  \/* Key: prevent wrapping, word breaks, and vertical text in headers *\/\n  table.ss-table th {\n    white-space:nowrap;       \/* Do not wrap *\/\n    word-break:normal;        \/* Don’t break words *\/\n    letter-spacing:normal;    \/* Prevent theme styles from stretching letters *\/\n    font-weight:600;\n    background:#f8fafc;\n  }\n\n  \/* Small screen optimization *\/\n  @media (max-width:480px){\n    table.ss-table th, table.ss-table td { padding:8px 10px; font-size:14px; }\n  }\n\u003c\/style\u003e\n\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis \u003cstrong\u003eSerpentine Belt – Fits MerCruiser Alpha\/Bravo V6\/V8 Engines (Replaces 57-865615Q03, 57-865615-003)\u003c\/strong\u003e is engineered for Mercury MerCruiser V6\/V8 (305, 350, 377 cid) engines from 2001–2016 (serial numbers 0M320025 through 2A455872). It fits Alpha configurations with closed cooling and Bravo configurations with standard cooling, ensuring reliable power transmission for engine accessories.\u003c\/p\u003e\n\u003cp\u003eIt is a direct replacement for MerCruiser part numbers 57-865615-003, 57-865615Q03, 57-8638763, 57-862807, 57-862087A1, and Sierra 18-15100.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eInstalls as a direct replacement for your original belt.\u003c\/li\u003e\n\u003cli\u003eConstructed from durable engineered elastomer with reinforcement fibers.\u003c\/li\u003e\n\u003cli\u003eDesigned for specific MerCruiser V6 and V8 engine cooling system configurations.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003ePart Number Matrix\u003c\/h2\u003e\n\u003cp\u003eUse this matrix to confirm equivalent references across OEM and aftermarket.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Part Number Matrix\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003ePart Number\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMerCruiser\u003c\/td\u003e\n        \u003ctd\u003e57-865615-003\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMerCruiser\u003c\/td\u003e\n        \u003ctd\u003e57-865615Q03\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMerCruiser\u003c\/td\u003e\n        \u003ctd\u003e57-8638763\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMerCruiser\u003c\/td\u003e\n        \u003ctd\u003e57-862807\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMerCruiser\u003c\/td\u003e\n        \u003ctd\u003e57-862087A1\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eSierra\u003c\/td\u003e\n        \u003ctd\u003e18-15100\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eEngine \u0026amp; Model Compatibility\u003c\/h2\u003e\n\u003cp\u003eConfirm your engine model\/year in the table below.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Engine \u0026amp; Model Compatibility\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003eModel\u003c\/th\u003e\n        \u003cth\u003eEngine Size\u003c\/th\u003e\n        \u003cth\u003eConfiguration\u003c\/th\u003e\n        \u003cth\u003eYears\u003c\/th\u003e\n        \u003cth\u003eOEM Part No.\u003c\/th\u003e\n        \u003cth\u003eNotes\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMerCruiser\u003c\/td\u003e\n        \u003ctd\u003eAlpha\u003c\/td\u003e\n        \u003ctd\u003e4.3L V6, 5.0L V8, 5.7L V8, 377 cid V8\u003c\/td\u003e\n        \u003ctd\u003eWith closed cooling system\u003c\/td\u003e\n        \u003ctd\u003e2001–2016\u003c\/td\u003e\n        \u003ctd\u003e57-865615-003, 57-865615Q03\u003c\/td\u003e\n        \u003ctd\u003eSerial numbers 0M320025 and above\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMerCruiser\u003c\/td\u003e\n        \u003ctd\u003eBravo\u003c\/td\u003e\n        \u003ctd\u003e4.3L V6, 5.0L V8, 5.7L V8, 377 cid V8\u003c\/td\u003e\n        \u003ctd\u003eWith standard cooling system\u003c\/td\u003e\n        \u003ctd\u003e2001–2016\u003c\/td\u003e\n        \u003ctd\u003e57-865615-003, 57-865615Q03\u003c\/td\u003e\n        \u003ctd\u003eSerial numbers 0M320025 through 2A455872\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specs\u003c\/h2\u003e\n\u003cdl\u003e\n  \u003cdt\u003eProduct Type\u003c\/dt\u003e\n\u003cdd\u003eSerpentine Belt\u003c\/dd\u003e\n  \u003cdt\u003eLength\u003c\/dt\u003e\n\u003cdd\u003e2,704 mm (106.5 in)\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n\u003cdd\u003eDirect replacement\u003c\/dd\u003e\n  \u003cdt\u003eMaterial\u003c\/dt\u003e\n\u003cdd\u003eEngineered elastomer with reinforcement fibers\u003c\/dd\u003e\n  \u003cdt\u003eCompatibility\u003c\/dt\u003e\n\u003cdd\u003eMerCruiser V6\/V8 engines with specific cooling configurations\u003c\/dd\u003e\n  \u003cdt\u003eUPC\u003c\/dt\u003e\n\u003cdd\u003e745061630437\u003c\/dd\u003e\n  \u003cdt\u003eWarranty\u003c\/dt\u003e\n\u003cdd\u003e1 Year\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e1 x Serpentine Belt (57-865615Q03)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eDisconnect the boat's battery before starting work.\u003c\/li\u003e\n  \u003cli\u003eLocate the serpentine belt and note its routing path around the pulleys. If needed, draw a diagram.\u003c\/li\u003e\n  \u003cli\u003eUse a long-handled breaker bar or a dedicated belt tensioner tool to rotate the automatic tensioner and release pressure on the belt.\u003c\/li\u003e\n  \u003cli\u003eWhile holding the tensioner, carefully slide the old belt off the pulleys.\u003c\/li\u003e\n  \u003cli\u003eWith the belt removed, inspect all pulleys for wobble, signs of wear, or damage. Spin them to ensure they rotate smoothly.\u003c\/li\u003e\n  \u003cli\u003eRoute the new belt according to your diagram, starting with the crankshaft pulley and leaving a smooth pulley (like the water pump) for last.\u003c\/li\u003e\n  \u003cli\u003eOnce the belt is routed correctly on all grooved pulleys, release the tensioner to apply pressure.\u003c\/li\u003e\n  \u003cli\u003e visually inspect the belt to ensure it is seated correctly in every pulley groove.\u003c\/li\u003e\n  \u003cli\u003eReconnect the battery and start the engine briefly to check for proper operation.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow do I know if this belt fits my engine?\u003c\/summary\u003e\n  \u003cp\u003eYour engine must match the criteria in the \"Engine \u0026amp; Model Compatibility\" section. This belt is for MerCruiser V6\/V8 engines (2001-2016): Alpha models with closed cooling (SN 0M320025+) and Bravo models with standard cooling (SN 0M320025 to 2A455872). Always verify your specific model and serial number.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat are the signs of a failing serpentine belt?\u003c\/summary\u003e\n  \u003cp\u003eCommon symptoms include a loud squealing noise from the engine bay, visible cracks or fraying on the belt's surface, chirping sounds that change with engine RPM, or dashboard warning lights for the battery or coolant temperature.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat is the recommended replacement interval?\u003c\/summary\u003e\n  \u003cp\u003eFor marine environments, it is best practice to inspect the belt at the beginning of each season and at regular service intervals. As a general guideline, consider replacement every 3-5 years, or immediately if you notice any signs of glazing, cracking, or other wear.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow is an aftermarket part different from OEM?\u003c\/summary\u003e\n  \u003cp\u003eThis listing is an aftermarket replacement, not an OEM component. It is manufactured in an ISO 9002 facility to meet or exceed original equipment specifications for fit, form, and function, offering a high-quality alternative at a better value.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat are your shipping and warranty policies?\u003c\/summary\u003e\n  \u003cp\u003eWe provide fast worldwide shipping, with most orders arriving in 5–15 days. Standard shipping is free, with expedited options available at checkout. The belt is covered by a 1-year warranty against manufacturing defects. If you have an issue, please contact our support team with your order details.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat if I order the wrong part?\u003c\/summary\u003e\n  \u003cp\u003eWe accept returns of unused items in their original condition within our standard return window. Please see our full policy page or contact us for instructions. We strongly recommend verifying compatibility before purchasing to avoid errors.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Info\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eVerify images and specifications against your original part before purchase. If anything differs, even if your model is listed as compatible, do not order.\u003c\/li\u003e\n  \u003cli\u003eThis is an aftermarket replacement part, not an original equipment manufacturer (OEM) component.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation is highly recommended to ensure proper fit, function, and safety.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePro-Grade Standards\u003c\/strong\u003e — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world conditions.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFast Global Fulfillment\u003c\/strong\u003e — With free standard delivery to most regions, you can expect your parts in 5–15 days.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer-Direct Value\u003c\/strong\u003e — By working directly with manufacturers, we offer fair pricing without compromising on materials or quality control.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50717884580155,"sku":"23BL234","price":24.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/23BL2341.jpg?v=1762937290","url":"https:\/\/seasierra.com\/products\/serpentine-belt-fits-mercruiser-alpha-bravo-v6-v8-engines-replaces-57-865615q03-57-865615-003","provider":"SeaSierra","version":"1.0","type":"link"}