{"product_id":"sierra-marine-v-belt-18-15550","title":"Sierra Marine V-Belt 18-15550 | 55 in. \/ 139.7 cm × 29\/64 in. \/ 11.5 mm","description":"\u003ch2\u003eSierra Marine V-Belt 18-15550\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePart Number:\u003c\/strong\u003e 18-15550 (Sierra)  |  \u003cstrong\u003eUPC:\u003c\/strong\u003e 030999566744\u003c\/p\u003e\n\u003cp\u003eThe Sierra 18-15550 is a cogged marine V-belt for selected MerCruiser big-block inboard and sterndrive accessory-drive systems. High-strength synthetic cords resist stretching and shock loading, while the precision-moulded cog profile improves flexibility and allows cooling airflow around the belt. Rubber sidewalls maintain positive contact with pulley grooves throughout the service interval.\u003c\/p\u003e\n\n\u003ch3\u003eBelt Specifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eEffective length:\u003c\/strong\u003e 55 in. \/ 139.7 cm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTop width:\u003c\/strong\u003e 29\/64 in. \/ 11.5 mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConstruction:\u003c\/strong\u003e Cogged, synthetic-rubber\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCord type:\u003c\/strong\u003e High-strength, low-stretch synthetic\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProfile:\u003c\/strong\u003e Moulded cog — improves flexibility and heat control\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSupplied as:\u003c\/strong\u003e Single belt\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eCompatible Applications\u003c\/h3\u003e\n\u003cp\u003eCataloged specifically against the MerCruiser 57-13458 belt family — not a universal 7.4 L replacement. Confirmed applications:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eMerCruiser 330 \/ GM 454 CID \/ 7.4 L — 1982–1987\u003c\/li\u003e\n\u003cli\u003eMerCruiser 454 MAG Alpha \/ 7.4 L — 1986–1989\u003c\/li\u003e\n\u003cli\u003eSelected MerCruiser 454 MAG Bravo \/ 7.4 L Bravo — early 1990s accessory-drive configurations\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFitment Notice\u003c\/h3\u003e\n\u003cp\u003eMerCruiser 454 and 7.4 L engines were produced with different alternator, water-pump, and power-steering belt arrangements depending on production year, drive model, and pulley layout. Engine displacement alone is not sufficient to confirm fitment. Before ordering, verify:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eEngine model and production year\u003c\/li\u003e\n\u003cli\u003eEngine serial number\u003c\/li\u003e\n\u003cli\u003eExisting OEM belt number\u003c\/li\u003e\n\u003cli\u003eAccessory-drive and pulley configuration\u003c\/li\u003e\n\u003cli\u003eRequired belt effective length and top width\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eOEM \u0026amp; Cross-Reference Part Numbers\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eSierra: \u003cstrong\u003e18-15550\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eMercury \/ MerCruiser: \u003cstrong\u003e57-13458\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eMercury \/ MerCruiser: \u003cstrong\u003e57-13458T\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eMercury \/ MerCruiser: \u003cstrong\u003e57-13458Q\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003cli\u003eMallory: \u003cstrong\u003e9-55000\u003c\/strong\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eNeed a different length? See related belts in the same series:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/11077659328548\"\u003eSierra 18-15400 V-Belt\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/11077659361316\"\u003eSierra 18-15410 Cogged V-Belt\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/11077659459620\"\u003eSierra 18-15450 V-Belt\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/11077659492388\"\u003eSierra 18-15455 V-Belt\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/11077659557924\"\u003eSierra 18-15460 Cogged V-Belt\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/11077659590692\"\u003eSierra 18-15470 Marine V-Belt — 47 in. \/ 119.4 cm\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/11077659623460\"\u003eSierra 18-15480 Marine V-Belt — 48 in. \/ 121.9 cm\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/11077659656228\"\u003eSierra 18-15520 Power Steering V-Belt — 52 in. \/ 132.1 cm\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhen to Replace the Belt\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eCracks visible between cogs or on belt edges\u003c\/li\u003e\n\u003cli\u003eFrayed or glazed belt surfaces\u003c\/li\u003e\n\u003cli\u003eSquealing or slipping under load\u003c\/li\u003e\n\u003cli\u003eBelt dust present around the pulleys\u003c\/li\u003e\n\u003cli\u003eProper tension can no longer be maintained\u003c\/li\u003e\n\u003cli\u003eOil or coolant contamination on the belt\u003c\/li\u003e\n\u003cli\u003eBelt riding unusually low in the pulley groove\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eInstallation Notes\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eInspect all pulleys for wear, corrosion, and misalignment before installation\u003c\/li\u003e\n\u003cli\u003eDo not pry the belt over pulley flanges with sharp tools\u003c\/li\u003e\n\u003cli\u003eConfirm correct belt routing and accessory alignment\u003c\/li\u003e\n\u003cli\u003eSet tension to the engine manufacturer's specification\u003c\/li\u003e\n\u003cli\u003eRotate the drive by hand to confirm the belt seats fully in each pulley groove\u003c\/li\u003e\n\u003cli\u003eRecheck tension after the initial operating period where specified\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eA belt failure on a MerCruiser big-block can simultaneously disable raw water cooling, power steering, and battery charging — consider carrying a spare onboard.\u003c\/p\u003e\n\n\u003ch3\u003eRelated Parts\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/8131430711332\"\u003eMercury MerCruiser Quicksilver Serpentine Belt 865615Q07\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/11077674762276\"\u003eSierra Serpentine Belt — Marine Inboard — 47-15103\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/11061072789540\"\u003eMarine Alternator 12V 65A — Replaces MerCruiser 805447T\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/11061072658468\"\u003eMarine Alternator 12V 55A — Replaces MerCruiser 817119A1\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/8131501490212\"\u003eVolvo Penta Power Steering V-Belt 3858462\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eParts Desk Insights\u003c\/h3\u003e\n\u003cp\u003eThe Sierra 18-15550 is the go-to pre-season replacement for owners of MerCruiser 330 GM 454 (1982–1987) and 454 MAG Alpha (1986–1989) boats. The most reliable confirmation method is matching the original OEM belt number: if it cross-references to 57-13458, 57-13458T, or 57-13458Q, this belt is in the correct interchange family.\u003c\/p\u003e\n\u003cp\u003eA common issue: customers order by engine displacement alone and receive the wrong belt. The 7.4 L \/ 454 family used several different accessory-drive layouts across model years and drive configurations. Always verify the OEM number and full pulley arrangement. Given the consequences of a belt failure at sea on a big-block — simultaneous loss of cooling, steering, and charging — keeping a spare onboard is strongly recommended for any extended cruise.\u003c\/p\u003e","brand":"LNS","offers":[{"title":"Default Title","offer_id":51037541367844,"sku":"47-15550","price":43.29,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/47-15128_9b666b72-6b49-46b6-a585-2d2f2e685b5f.jpg?v=1783568596","url":"https:\/\/marisolmarine.com\/products\/sierra-marine-v-belt-18-15550","provider":"Marisol Marine Company","version":"1.0","type":"link"}