{"product_id":"bellow-retainer-ring-installation-tool-fits-mercury-mercruiser-alpha-1-gen-2-bravo-blackhawk-replaces-91-818162","title":"Bellow Retainer Ring Installation Tool – Fits Mercury MerCruiser Alpha 1 Gen 2, Bravo, Blackhawk (Replaces 91-818162)","description":"\u003csection\u003e\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis specialized \u003cstrong\u003eBellow Retainer Ring Installation Tool\u003c\/strong\u003e is designed for installing the aluminum retainer ring inside the U-joint bellows on Mercury MerCruiser Alpha One Generation 2, Bravo, and Blackhawk sterndrives (1988–Present).\u003c\/p\u003e\n\u003cp\u003eIt serves as a direct replacement for multiple part numbers, including Mercury Marine 91-818162, Sierra 18-9870, and Mallory 9-79821.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSpecialized tool for installing the aluminum retainer ring into U-joint bellows.\u003c\/li\u003e\n\u003cli\u003eConstructed from high-strength aluminum for durability and precision.\u003c\/li\u003e\n\u003cli\u003eRequires a compatible driver rod for proper use.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cstyle\u003e\n  .ss-table-wrap { overflow-x:auto; -webkit-overflow-scrolling:touch; }\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  table.ss-table th {\n    white-space:nowrap;\n    word-break:normal;\n    letter-spacing:normal;\n    font-weight:600;\n    background:#f8fafc;\n  }\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\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 Marine\u003c\/td\u003e\n\u003ctd\u003e91-818162\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMercury Marine\u003c\/td\u003e\n\u003ctd\u003e43577\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-9870\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMallory\u003c\/td\u003e\n\u003ctd\u003e9-79821\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eMallory\u003c\/td\u003e\n\u003ctd\u003e79821\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eHeuroFosh\u003c\/td\u003e\n\u003ctd\u003e818162\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\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 tool is compatible with a range of Mercury Marine sterndrives from 1988 to the present day.\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        \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\u003eAlpha One Gen II\u003c\/td\u003e\n        \u003ctd\u003e120–300\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1992–Present\u003c\/td\u003e\n        \u003ctd\u003e91-818162\u003c\/td\u003e\n        \u003ctd\u003ePrimary application\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eBravo One\u003c\/td\u003e\n        \u003ctd\u003e250–500+\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1988–Present\u003c\/td\u003e\n        \u003ctd\u003e91-818162\u003c\/td\u003e\n        \u003ctd\u003eHigh-performance drives\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eBravo Two\u003c\/td\u003e\n        \u003ctd\u003e300–500+\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1989–Present\u003c\/td\u003e\n        \u003ctd\u003e91-818162\u003c\/td\u003e\n        \u003ctd\u003eHeavy-duty applications\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eBravo Three\u003c\/td\u003e\n        \u003ctd\u003e250–500+\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1988–Present\u003c\/td\u003e\n        \u003ctd\u003e91-818162\u003c\/td\u003e\n        \u003ctd\u003eDual-prop configuration\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMercury\u003c\/td\u003e\n        \u003ctd\u003eBlackhawk\u003c\/td\u003e\n        \u003ctd\u003e300–500+\u003c\/td\u003e\n        \u003ctd\u003e4-Stroke\u003c\/td\u003e\n        \u003ctd\u003e1994–1998\u003c\/td\u003e\n        \u003ctd\u003e91-818162\u003c\/td\u003e\n        \u003ctd\u003eSurface drive system\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\u003ch2\u003eTechnical Specs\u003c\/h2\u003e\n\u003cdl\u003e\n  \u003cdt\u003eProduct Type\u003c\/dt\u003e\n\u003cdd\u003eDrive Shaft Bellow Sleeve Installation Tool\u003c\/dd\u003e\n  \u003cdt\u003eApplication\u003c\/dt\u003e\n\u003cdd\u003eSpecialized tool for installing aluminum retainer ring into U-joint bellows\u003c\/dd\u003e\n  \u003cdt\u003eHousing Material\u003c\/dt\u003e\n\u003cdd\u003eAluminum (Note: some aftermarket models may use PVC plastic)\u003c\/dd\u003e\n  \u003cdt\u003eDimensions\u003c\/dt\u003e\n\u003cdd\u003eApproximately 89 mm diameter x 25 mm height (3.5\" x 1\")\u003c\/dd\u003e\n  \u003cdt\u003eWeight\u003c\/dt\u003e\n\u003cdd\u003eApproximately 150 g (0.33 lb)\u003c\/dd\u003e\n  \u003cdt\u003ePackage Dimensions\u003c\/dt\u003e\n\u003cdd\u003e15 cm x 10 cm x 3 cm\u003c\/dd\u003e\n  \u003cdt\u003eFitting Type\u003c\/dt\u003e\n\u003cdd\u003ePrecision-machined installation sleeve\u003c\/dd\u003e\n  \u003cdt\u003eOperating Temperature\u003c\/dt\u003e\n\u003cdd\u003eStandard ambient conditions (-10°C to 50°C \/ 14°F to 122°F)\u003c\/dd\u003e\n  \u003cdt\u003eWarranty\u003c\/dt\u003e\n\u003cdd\u003e1-year against manufacturing defects (varies by manufacturer)\u003c\/dd\u003e\n  \u003cdt\u003eAdditional Requirements\u003c\/dt\u003e\n\u003cdd\u003eRequires driver rod and installer tool for optimal performance; engine alignment tool needed for use\u003c\/dd\u003e\n\u003c\/dl\u003e\n\u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e1 x Bellow Retainer Ring Installation Tool (\u003cspan style=\"color:#d0021b;\"\u003e91-818162\u003c\/span\u003e)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n\u003cli\u003eEnsure the sterndrive unit is safely tilted up and accessible.\u003c\/li\u003e\n\u003cli\u003ePlace the new U-joint bellows onto the gimbal housing.\u003c\/li\u003e\n\u003cli\u003eInsert the aluminum retainer ring into the designated groove on the new bellows.\u003c\/li\u003e\n\u003cli\u003ePosition this sleeve installation tool evenly over the retainer ring.\u003c\/li\u003e\n\u003cli\u003eUsing a compatible driver rod, carefully apply pressure to drive the tool, seating the ring securely into the bellow's groove.\u003c\/li\u003e\n\u003cli\u003eOnce fully seated, visually inspect the ring to confirm it is flush and evenly installed.\u003c\/li\u003e\n\u003cli\u003eCarefully remove the installation tool. The bellows is now secured.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat sterndrive series does this tool fit?\u003c\/summary\u003e\u003cp\u003eThis tool is designed for Mercury MerCruiser Alpha One Gen II, Bravo (One, Two, Three), and Blackhawk series sterndrives from 1988 to present.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eIs this tool made of aluminum or plastic?\u003c\/summary\u003e\u003cp\u003eOur tool is constructed from high-strength aluminum, following the OEM specification. Some other aftermarket suppliers may offer versions made from PVC plastic, but we use aluminum for superior durability and a precise fit.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat other tools are required to use this installer?\u003c\/summary\u003e\u003cp\u003eFor optimal performance, you will need a compatible driver rod to apply even pressure. It is also recommended to use an engine alignment tool during the overall bellows replacement process to ensure correct drive alignment.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow do I know the retainer ring is installed correctly?\u003c\/summary\u003e\u003cp\u003eAfter using the tool, perform a visual inspection. The aluminum retainer ring should be fully seated and sit flush within the bellow's groove. There should be no gaps or unevenness.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eOEM vs. Aftermarket?\u003c\/summary\u003e\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\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eShipping speed \u0026amp; cost\u003c\/summary\u003e\u003cp\u003eWe ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eWarranty \u0026amp; returns\u003c\/summary\u003e\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\u003c\/details\u003e\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\u003ch2\u003eAbout Sea Sierra\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003ePro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.\u003c\/li\u003e\n\u003cli\u003eFast Global Fulfillment — Free standard delivery to most regions in 5–15 days.\u003c\/li\u003e\n\u003cli\u003eManufacturer-Direct Value — 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":50718265442619,"sku":"KO-P085-MZ0E","price":12.58,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/KO-P085-MZ0E.png?v=1762958513","url":"https:\/\/seasierra.com\/products\/bellow-retainer-ring-installation-tool-fits-mercury-mercruiser-alpha-1-gen-2-bravo-blackhawk-replaces-91-818162","provider":"SeaSierra","version":"1.0","type":"link"}