{"product_id":"thermostat-housing-with-o-ring-kit-fits-mercury-marine-verado-135-400-hp-replaces-892864t04-8m0174561","title":"Thermostat Housing with O-Ring Kit – Fits Mercury Marine Verado 135-400 HP (Replaces 892864T04\/8M0174561)","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\u003eThermostat Housing with O-Ring Kit\u003c\/strong\u003e is a complete assembly designed for a wide range of Mercury Marine Verado engines. It ensures your engine maintains the correct operating temperature for optimal performance and longevity, fitting L4 and L6 Verado models from 135 HP to 400 HP, manufactured from 2004 to the present.\u003c\/p\u003e\n\u003cp\u003eIt serves as a direct replacement for Mercury part numbers 892864T04 and 8M0174561, as well as Sierra interchanges 18-3631 and 18-3631-K.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eEngineered for direct OEM-replacement installation.\u003c\/li\u003e\n  \u003cli\u003eThe kit includes the thermostat, housing, and necessary O-ring.\u003c\/li\u003e\n  \u003cli\u003eFeatures a durable metal alloy housing and a brass thermostat mechanism.\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 Cross-Reference\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003ePart Number\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\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e892864T04\u003c\/td\u003e\n        \u003ctd\u003eSuperseded by 8M0174561\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e8M0174561\u003c\/td\u003e\n        \u003ctd\u003eCurrent OEM Part\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eSierra\u003c\/td\u003e\n        \u003ctd\u003e18-3631\u003c\/td\u003e\n        \u003ctd\u003eInterchangeable part\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eSierra\u003c\/td\u003e\n        \u003ctd\u003e18-3631-K\u003c\/td\u003e\n        \u003ctd\u003eInterchangeable kit\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eAftermarket\u003c\/td\u003e\n        \u003ctd\u003eREC892864T04\u003c\/td\u003e\n        \u003ctd\u003eInterchangeable part\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\u003cp\u003eThis part is designed exclusively for Mercury Marine Verado engines. Please check your serial number to ensure precise fitment.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Engine Model Compatibility\"\u003e\n    \u003cthead\u003e\n      \u003ctr\u003e\n        \u003cth\u003eBrand\u003c\/th\u003e\n        \u003cth\u003eModel\u003c\/th\u003e\n        \u003cth\u003eRated HP\u003c\/th\u003e\n        \u003cth\u003eStroke\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\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L4\u003c\/td\u003e\n        \u003ctd\u003e135\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Present (1B227000-2B576734)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003e4-cylinder models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L4\u003c\/td\u003e\n        \u003ctd\u003e150\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Present (1B227000-2B576734)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003e4-cylinder models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L4\u003c\/td\u003e\n        \u003ctd\u003e175\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Present (1B227000-2B576734)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003e4-cylinder models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L4\u003c\/td\u003e\n        \u003ctd\u003e200\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Present (1B517159-2B576734)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003e4-cylinder models\u003c\/td\u003e\n      \u003c\/tr\u003e\n\u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L6\u003c\/td\u003e\n        \u003ctd\u003e200\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Present (0T980000-2B578935)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003e6-cylinder models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L6 Pro\u003c\/td\u003e\n        \u003ctd\u003e200\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Present (2B034840-2B577715)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003ePro 6-cylinder models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L6\u003c\/td\u003e\n        \u003ctd\u003e225\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Present (0T980000-2B578935)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003e6-cylinder models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L6\u003c\/td\u003e\n        \u003ctd\u003e250\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Present (0T980000-2B578935)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003e6-cylinder models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L6 Pro\u003c\/td\u003e\n        \u003ctd\u003e250\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Present (1B830170-2B577715)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003ePro 6-cylinder models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L6\u003c\/td\u003e\n        \u003ctd\u003e275\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Present (0T980000-2B578935)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003e6-cylinder models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L6\u003c\/td\u003e\n        \u003ctd\u003e300\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Present (1B517434-2B578935)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003e6-cylinder models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L6 Pro\u003c\/td\u003e\n        \u003ctd\u003e300\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2004–Present (1B830170-2B577715)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003ePro 6-cylinder models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L6 Pro\u003c\/td\u003e\n        \u003ctd\u003e350\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2015–Present (2B141124-3B342962)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003e2.6L L6 Pro models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L6\u003c\/td\u003e\n        \u003ctd\u003e350\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2015–Present (2B141617-3B342962)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003e2.6L L6 models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eVerado L6\u003c\/td\u003e\n        \u003ctd\u003e400\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2016–Present (2B618256-3B342962)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003e2.6L L6 models\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eRacing L6\u003c\/td\u003e\n        \u003ctd\u003e400R\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2015–Present (2B141124-3B342962)\u003c\/td\u003e\n        \u003ctd\u003e892864T04\/8M0174561\u003c\/td\u003e\n        \u003ctd\u003e2.6L L6 Racing models\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\u003eThermostat Housing Assembly\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n\u003cdd\u003eDirect OEM replacement\u003c\/dd\u003e\n  \u003cdt\u003eTemperature Rating\u003c\/dt\u003e\n\u003cdd\u003e140°F (60°C)\u003c\/dd\u003e\n  \u003cdt\u003eHousing Material\u003c\/dt\u003e\n\u003cdd\u003eMetal alloy with brass thermostat mechanism\u003c\/dd\u003e\n  \u003cdt\u003eConnection\u003c\/dt\u003e\n\u003cdd\u003eHose connection with clamp\u003c\/dd\u003e\n  \u003cdt\u003eOperating Temperature\u003c\/dt\u003e\n\u003cdd\u003eStandard marine operating range\u003c\/dd\u003e\n  \u003cdt\u003eOther Technical Attributes\u003c\/dt\u003e\n\u003cdd\u003eIncludes thermostat, housing, and necessary O-ring\u003c\/dd\u003e\n  \u003cdt\u003eWarranty\u003c\/dt\u003e\n\u003cdd\u003eManufacturer warranty varies by brand (Mercury OEM: 1 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 Thermostat with Housing Assembly (892864T04\/8M0174561)\u003c\/li\u003e\n  \u003cli\u003e1 x O-Ring seal (8M005958)\u003c\/li\u003e\n  \u003cli\u003e1 x Oetiker Clamp (888988008) - included with some kits\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eAlways allow the engine to cool completely before starting work.\u003c\/li\u003e\n  \u003cli\u003eDisconnect the boat's battery for safety.\u003c\/li\u003e\n  \u003cli\u003eDrain the engine coolant into a suitable container.\u003c\/li\u003e\n  \u003cli\u003eLocate the thermostat housing and carefully disconnect the attached hoses.\u003c\/li\u003e\n  \u003cli\u003eUnbolt and remove the old thermostat housing assembly. Note the orientation of the old part.\u003c\/li\u003e\n  \u003cli\u003eThoroughly clean the mating surface on the engine block, removing any old gasket or sealant material.\u003c\/li\u003e\n  \u003cli\u003eInstall the new O-ring and place the new thermostat assembly into position.\u003c\/li\u003e\n  \u003cli\u003eTighten the mounting bolts to the manufacturer-specified torque in a crisscross pattern.\u003c\/li\u003e\n  \u003cli\u003eReconnect the hoses and secure them with clamps.\u003c\/li\u003e\n  \u003cli\u003eRefill the cooling system with the appropriate coolant.\u003c\/li\u003e\n  \u003cli\u003eReconnect the battery, start the engine, and carefully check for leaks as it comes up to temperature.\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 my thermostat is failing?\u003c\/summary\u003e\n  \u003cp\u003eSigns of a failing thermostat include the engine overheating, the temperature gauge reading unusually low, erratic temperature fluctuations, and potential coolant leaks around the housing. These symptoms indicate the thermostat is stuck open or closed.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat is the purpose of the 140°F temperature rating?\u003c\/summary\u003e\n  \u003cp\u003eThe 140°F (60°C) rating is the temperature at which the thermostat begins to open, allowing coolant to circulate through the engine. This helps the engine warm up quickly and then maintains a stable operating temperature for optimal efficiency and performance.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs the O-ring included necessary for installation?\u003c\/summary\u003e\n  \u003cp\u003eYes, the included O-ring is critical for creating a proper seal between the thermostat housing and the engine. Never reuse an old O-ring, as it can lead to coolant leaks and overheating.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs this part compatible with non-Verado Mercury engines?\u003c\/summary\u003e\n  \u003cp\u003eNo, this specific thermostat kit is designed exclusively for the Mercury Verado L4 \u0026amp; L6 engine family. Using it on other models will likely result in improper fitment and engine cooling issues. Always check the compatibility table.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eOEM vs. Aftermarket?\u003c\/summary\u003e\n  \u003cp\u003eThis listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eShipping speed \u0026amp; cost\u003c\/summary\u003e\n  \u003cp\u003eWe ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.\u003c\/p\u003e\n\u003c\/details\u003e\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50718269342011,"sku":"21TH009","price":70.49,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Thermostat_with_Housing_Kit_for_Mercury_Marine_135-300_HP_Verado_Outboard_Motors___________892864T04_-_JLM_MARINE-8286910.jpg?v=1762958666","url":"https:\/\/seasierra.com\/products\/thermostat-housing-with-o-ring-kit-fits-mercury-marine-verado-135-400-hp-replaces-892864t04-8m0174561","provider":"SeaSierra","version":"1.0","type":"link"}