{"product_id":"gearcase-seal-kit-fits-mercury-mariner-150-hp-efi-fourstroke-replaces-8m0057716","title":"Gearcase Seal Kit – Fits Mercury\/Mariner 150 HP EFI FourStroke (Replaces 8M0057716)","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\u003eGearcase Seal Kit – Fits Mercury\/Mariner 150 HP EFI FourStroke Outboards (Replaces 8M0057716)\u003c\/strong\u003e contains the necessary components to service the lower unit on Mercury\/Mariner 150 HP EFI FourStroke outboard engines from 2007 and newer (serial number 1B905505 and up). It provides a complete solution for replacing worn or damaged seals to prevent water intrusion and oil leaks.\u003c\/p\u003e\n\u003cp\u003eThis kit is a direct replacement for Mercury part number 8M0057716 and GLM Marine 87527.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eIncludes all necessary gaskets and seals for a complete gearcase service.\u003c\/li\u003e\n  \u003cli\u003eEngineered with high-quality, corrosion-resistant materials for durability in marine environments.\u003c\/li\u003e\n  \u003cli\u003eEstablishes a watertight seal to protect internal gearcase components from water intrusion.\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\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e8M0057716\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eGLM Marine\u003c\/td\u003e\n        \u003ctd\u003e87527\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\u003eFor Mercury and Mariner owners, please verify your engine's model, horsepower, and serial number range to ensure correct fitment.\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\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      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\/Mariner\u003c\/td\u003e\n        \u003ctd\u003eFourStroke\u003c\/td\u003e\n        \u003ctd\u003e150\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2007 and up (SN 1B905505 \u0026amp; up)\u003c\/td\u003e\n        \u003ctd\u003e8M0057716\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eSea Pro\u003c\/td\u003e\n        \u003ctd\u003e150\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e(SN 2B139139 \u0026amp; up)\u003c\/td\u003e\n        \u003ctd\u003e8M0057716\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\/Mariner\u003c\/td\u003e\n        \u003ctd\u003eEFI\u003c\/td\u003e\n        \u003ctd\u003e135\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e(SN 2B131942 \u0026amp; up)\u003c\/td\u003e\n        \u003ctd\u003e8M0057716\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003e7150F23ZD, 7150F24ZD, 7150F13ZD\u003c\/td\u003e\n        \u003ctd\u003e150\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e2011\u003c\/td\u003e\n        \u003ctd\u003e8M0057716\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\u003eGearcase Seal Kit\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n\u003cdd\u003eGaskets and seals for gearcase\/lower unit\u003c\/dd\u003e\n  \u003cdt\u003eHousing Material\u003c\/dt\u003e\n\u003cdd\u003eHigh-quality, corrosion-resistant materials\u003c\/dd\u003e\n  \u003cdt\u003eWeight\u003c\/dt\u003e\n\u003cdd\u003e0.29 lb (0.13 kg)\u003c\/dd\u003e\n  \u003cdt\u003eOther Technical Attributes\u003c\/dt\u003e\n\u003cdd\u003eWatertight seal for protection against water intrusion\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n\u003cp\u003eThis kit includes all components listed below. Note that quantities were not available at the time of publication.\u003c\/p\u003e\n\u003cul\u003e\n    \u003cli\u003eSEAL (Replaces OEM 830749)\u003c\/li\u003e\n    \u003cli\u003eSEAL, Oil (Replaces OEM 89238)\u003c\/li\u003e\n    \u003cli\u003eO-RING, (2.175 x .103) (Replaces OEM 896523)\u003c\/li\u003e\n    \u003cli\u003eO-RING, (.987 x .103) (Replaces OEM 45258)\u003c\/li\u003e\n    \u003cli\u003eO-RING, (.796 x .139) (Replaces OEM 21836)\u003c\/li\u003e\n    \u003cli\u003eSEAL, Oil (Replaces OEM 816464 1)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003ePosition the outboard securely and place a drain pan under the lower unit. Remove the gear lube drain and vent screws to drain the gearcase oil completely.\u003c\/li\u003e\n  \u003cli\u003eRemove the propeller and mounting hardware. Disconnect the speedometer tube if equipped.\u003c\/li\u003e\n  \u003cli\u003eUnbolt and carefully remove the gearcase (lower unit) from the outboard's driveshaft housing.\u003c\/li\u003e\n  \u003cli\u003eDisassemble the gearcase components, including the bearing carrier and driveshaft, taking care to note the order and orientation of parts.\u003c\/li\u003e\n  \u003cli\u003eCarefully remove all old seals, O-rings, and gaskets from their respective locations. Thoroughly clean all sealing surfaces.\u003c\/li\u003e\n  \u003cli\u003eInstall the new seals and O-rings from the kit, applying a light coat of marine grease to help with installation and sealing.\u003c\/li\u003e\n  \u003cli\u003eReassemble the gearcase components in reverse order, ensuring all parts are correctly seated and torqued to manufacturer specifications.\u003c\/li\u003e\n  \u003cli\u003eReinstall the lower unit onto the outboard, ensuring the driveshaft, water tube, and shift shaft are properly aligned.\u003c\/li\u003e\n  \u003cli\u003eRefill the gearcase with the manufacturer-recommended gear lube until it flows from the upper vent hole, then reinstall and tighten both screws.\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 gearcase seals are failing?\u003c\/summary\u003e\n  \u003cp\u003eCommon signs of failing gearcase seals include a milky, white, or creamy appearance in the gear lube (indicating water intrusion) or visible oil leaks around the propeller shaft or lower unit housing. A pressure and vacuum test can also confirm a leak.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWill this kit fit Mercury models other than the 150 HP FourStroke?\u003c\/summary\u003e\n  \u003cp\u003eYes, this kit is also listed as compatible with select 135 HP FourStroke EFI models (serial number 2B131942 and up) and 150 HP Sea Pro models (serial number 2B139139 and up). Always verify your engine's serial number against the compatibility table.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eHow often should I replace my gearcase seals?\u003c\/summary\u003e\n  \u003cp\u003eThere is no fixed replacement interval, but it is best practice to inspect the gear lube color during every annual service or 100-hour interval. Seals should be replaced immediately if water intrusion is found or if the lower unit is disassembled for other service.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eIs this kit a complete rebuild kit?\u003c\/summary\u003e\n  \u003cp\u003eThis is a seal kit, designed to address leaks and routine service. It contains gaskets, seals, and O-rings but does not typically include bearings, gears, or other hard parts. Please review the 'What’s in the Box' section for a list of included components.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n  \u003csummary\u003eWhat is the main difference between this aftermarket kit and an OEM kit?\u003c\/summary\u003e\n  \u003cp\u003eOur aftermarket kits are designed to meet or exceed OEM specifications for fit, function, and material quality at a more competitive price point. While the parts are not branded by the original engine manufacturer, they are produced in an ISO 9002 certified facility and undergo rigorous quality control.\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\n\u003cdetails\u003e\n  \u003csummary\u003eWarranty \u0026amp; returns?\u003c\/summary\u003e\n  \u003cp\u003eCovered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused \u0026amp; in original condition). See our policy page or reach out for instructions.\u003c\/p\u003e\n\u003c\/details\u003e\n\n\u003ch2\u003eSafety \u0026amp; Important Info\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eVerify images\/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.\u003c\/li\u003e\n  \u003cli\u003eThis is an aftermarket replacement, not an OEM component.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation is recommended for safety and performance.\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 tested for real-world conditions.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFast Global Fulfillment\u003c\/strong\u003e — Free standard delivery to most regions in 5–15 days.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer-Direct Value\u003c\/strong\u003e — Fair pricing without compromising on materials or QC.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":50718268719419,"sku":"21KM004","price":56.3,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/Seal_Kit_for_Mercury_MerCruiser_Gearcase_8M0057716_-_JLM_MARINE-8289974.jpg?v=1762958642","url":"https:\/\/seasierra.com\/products\/gearcase-seal-kit-fits-mercury-mariner-150-hp-efi-fourstroke-replaces-8m0057716","provider":"SeaSierra","version":"1.0","type":"link"}