{"product_id":"sierra-18-6457-composite-serpentine-pulley-replaces-807757t-fits-late-model-gm-v6-v8-marine-engines-3-od-13-16-belt","title":"Sierra 18-6457 Composite Pulley, Replaces 807757T, for Late Model GM V6 \u0026 V8 Engines","description":"\u003cp\u003eThe Sierra 18-6457 is a composite pulley engineered for late model GM V6 and V8 engines in MerCruiser sterndrive (I\/O) cooling system applications. It has a 3 inch outer diameter and is sized for a 13\/16 inch width serpentine belt, making it a direct fit for the serpentine belt drive on these engines. The pulley body is molded from composite material, offering a lightweight alternative to a stamped-steel pulley while standing up to the heat, moisture, and vibration of a marine engine compartment.\u003c\/p\u003e\u003cp\u003eThis pulley is a replacement part for 807757T and is built to restore proper belt alignment and tension on the accessory drive of applicable GM V6 and V8 marine engines. It is a straightforward swap for a worn, cracked, or wobbling factory pulley, helping keep the serpentine belt tracking correctly and reducing belt slip or premature wear.\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 18-6457\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Composite Pulley\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOuter Diameter:\u003c\/strong\u003e 3 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBelt Width Compatibility:\u003c\/strong\u003e 13\/16 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePulley Style:\u003c\/strong\u003e Serpentine\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Application:\u003c\/strong\u003e Late model GM V6 \u0026amp; V8 engines\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e White\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e Composite\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.12 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282200527\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eFits late model GM V6 and V8 engines used in MerCruiser sterndrive (I\/O) cooling system applications, using a serpentine belt of 13\/16 inch width.\u003c\/p\u003e\u003ch3\u003eReplaces (OEM)\u003c\/h3\u003e\u003cp\u003e807757T\u003c\/p\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines does the Sierra 18-6457 pulley fit?\u003c\/strong\u003e The Sierra 18-6457 composite pulley fits late model GM V6 and V8 engines used in MerCruiser sterndrive (I\/O) cooling system applications.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat belt size does this pulley use?\u003c\/strong\u003e It is sized for a 13\/16 inch width serpentine belt, matching the outer diameter and groove profile of the 3 inch pulley.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the outer diameter of the 18-6457 pulley?\u003c\/strong\u003e 3 inches, measured across the outside of the composite pulley wheel.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-6457 replace part number 807757T?\u003c\/strong\u003e Yes, part number 18-6457 is a direct replacement for 807757T.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat material is the pulley made of?\u003c\/strong\u003e The pulley body is made of composite material rather than stamped steel, and it is finished in white.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-6457 pulley weigh?\u003c\/strong\u003e It weighs 0.12 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this a genuine Sierra part or an aftermarket copy?\u003c\/strong\u003e Part number 18-6457 is a genuine Sierra composite pulley, sold under the Sierra brand as a replacement for OEM part 807757T.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order the 18-6457?\u003c\/strong\u003e The order includes one Sierra 18-6457 composite pulley; no mounting hardware or belt is included.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill this pulley work on a non-GM engine?\u003c\/strong\u003e The 18-6457 is designated for late model GM V6 and V8 engines; fitment on other engine families is not specified for this part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat system is this pulley used on?\u003c\/strong\u003e The Sierra 18-6457 is used on the serpentine belt drive of the cooling system on applicable MerCruiser I\/O engines.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988357624027,"sku":"SIE-18-6457","price":43.54,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/SIE-18-6457_lg__18946.1558128943.500.750.jpg?v=1785188974","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-6457-composite-serpentine-pulley-replaces-807757t-fits-late-model-gm-v6-v8-marine-engines-3-od-13-16-belt","provider":"Good Vibes Marina","version":"1.0","type":"link"}