{"product_id":"lower-unit-seal-kit-fits-johnson-evinrude-85-100-125-hp-replaces-18-2691-87611","title":"Lower Unit Seal Kit – Fits Johnson\/Evinrude 85\/100\/125 HP (Replaces 18-2691, 87611)","description":"\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\u003csection\u003e\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis aftermarket \u003cstrong\u003eLower Unit Seal Kit\u003c\/strong\u003e is designed for Johnson\/Evinrude 85, 100, and 125 HP 2-stroke outboard models from 1971–1972 that are equipped with a large prop shaft. It provides the necessary seals, gaskets, and O-rings to service the lower gearcase, preventing water intrusion and gear oil leaks.\u003c\/p\u003e\n\u003cp\u003eThis kit is a direct interchange for several part numbers, including Sierra 18-2691, GLM 87611, and Mallory 9-74114, ensuring broad compatibility.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eEngineered for direct replacement installation.\u003c\/li\u003e\n\u003cli\u003eSpecifically designed for models requiring seals for a large prop shaft.\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 brands.\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\u003eSierra\u003c\/td\u003e\n        \u003ctd\u003e18-2691\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eGLM\u003c\/td\u003e\n        \u003ctd\u003e87611\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eMallory\u003c\/td\u003e\n        \u003ctd\u003e9-74114\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 Johnson\/Evinrude owners: Please verify your specific model and year against this list, paying close attention to the \"Notes\" column. This kit is only compatible with models featuring a large prop shaft.\u003c\/p\u003e\n\u003cdiv class=\"ss-table-wrap\"\u003e\n  \u003ctable class=\"ss-table\" aria-label=\"Engine \u0026amp; Model Compatibility for Johnson\/Evinrude\"\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\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e85193A\u003c\/td\u003e\n\u003ctd\u003e85\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e85193H\u003c\/td\u003e\n\u003ctd\u003e85\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e85293R\u003c\/td\u003e\n\u003ctd\u003e85\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1972\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e85ESL71\u003c\/td\u003e\n\u003ctd\u003e85\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e85ESL72\u003c\/td\u003e\n\u003ctd\u003e85\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1972\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e100193A\u003c\/td\u003e\n\u003ctd\u003e100\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e100193C\u003c\/td\u003e\n\u003ctd\u003e100\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e100293\u003c\/td\u003e\n\u003ctd\u003e100\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1972\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e100ESL71\u003c\/td\u003e\n\u003ctd\u003e100\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e100ESL72\u003c\/td\u003e\n\u003ctd\u003e100\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1972\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e125183C\u003c\/td\u003e\n\u003ctd\u003e125\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e125283R\u003c\/td\u003e\n\u003ctd\u003e125\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1972\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e125ESL71\u003c\/td\u003e\n\u003ctd\u003e125\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1971\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003ctr\u003e\n\u003ctd\u003eJohnson\/Evinrude\u003c\/td\u003e\n\u003ctd\u003e125ESL72\u003c\/td\u003e\n\u003ctd\u003e125\u003c\/td\u003e\n\u003ctd\u003e2-Stroke\u003c\/td\u003e\n\u003ctd\u003e1972\u003c\/td\u003e\n\u003ctd\u003e18-2691\u003c\/td\u003e\n\u003ctd\u003eLarge Prop Shaft\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\u003eLower Unit\/Gearcase Seal Kit\u003c\/dd\u003e\n  \u003cdt\u003eInstallation\u003c\/dt\u003e\n\u003cdd\u003eDirect replacement\u003c\/dd\u003e\n  \u003cdt\u003eOther Technical Attributes\u003c\/dt\u003e\n\u003cdd\u003eFor large prop shaft models\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat’s in the Box\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eOil Seals\u003c\/li\u003e\n  \u003cli\u003eO-rings\u003c\/li\u003e\n  \u003cli\u003eGaskets\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n  \u003cli\u003eDrain the old gearcase lubricant completely from the lower unit.\u003c\/li\u003e\n  \u003cli\u003eRemove the propeller assembly and unbolt the lower unit from the outboard's leg.\u003c\/li\u003e\n  \u003cli\u003eDisassemble the gearcase to access the driveshaft and prop shaft carriers. Carefully remove old seals, O-rings, and gaskets, taking care not to scratch sealing surfaces.\u003c\/li\u003e\n  \u003cli\u003eThoroughly clean all component surfaces of old adhesive, corrosion, and debris.\u003c\/li\u003e\n  \u003cli\u003eLightly lubricate the new seals and O-rings with marine grease before carefully pressing them into place using an appropriate seal driver.\u003c\/li\u003e\n  \u003cli\u003eReassemble the gearcase components, ensuring all bolts are tightened to the manufacturer's specified torque sequence.\u003c\/li\u003e\n  \u003cli\u003eBefore reinstalling the unit, perform both a vacuum and pressure test (typically 10-12 PSI) to confirm the new seals are seated correctly and have no leaks.\u003c\/li\u003e\n  \u003cli\u003eRefill the lower unit with the correct grade and amount of marine gear lubricant. Reinstall the lower unit and check for leaks after the first use.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\u003csummary\u003eWhat are the signs that my lower unit seals are failing?\u003c\/summary\u003e\u003cp\u003eCommon symptoms include milky or foamy gear oil (indicating water intrusion), visible oil leaks dripping from the propeller shaft area, or excessive metal debris on the magnetic drain plug, often resulting from corrosion and wear caused by water contamination.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow do I confirm this kit is correct for my engine?\u003c\/summary\u003e\u003cp\u003eThis kit fits specific Johnson\/Evinrude 85, 100, and 125 HP models from 1971–1972 with a large prop shaft. Always match your full engine model number (e.g., 100ESL72) and year to the compatibility table. Do not order based on horsepower alone.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eIs any special tool required for installation?\u003c\/summary\u003e\u003cp\u003eWhile basic service is possible with standard tools, professional installation is recommended. Specialized tools like a seal puller, bearing carrier retainer wrench, and a pressure\/vacuum tester are often necessary to ensure seals are removed, installed, and tested correctly without damaging components.\u003c\/p\u003e\u003c\/details\u003e\n\u003cdetails\u003e\u003csummary\u003eHow often should lower unit seals be replaced?\u003c\/summary\u003e\u003cp\u003eSeals should be replaced as a preventative measure every few seasons, or immediately if you notice any signs of leaks or water in the gear oil during your routine annual service. It is not based on hours but on inspection results.\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\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\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":50718257742139,"sku":"OSK706","price":99.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/OSK706.png?v=1762958228","url":"https:\/\/seasierra.com\/products\/lower-unit-seal-kit-fits-johnson-evinrude-85-100-125-hp-replaces-18-2691-87611","provider":"SeaSierra","version":"1.0","type":"link"}