{"product_id":"lower-unit-oil-seal-fits-yamaha-40hp-70hp-80hp-100hp-4-stroke-replaces-2807-93101-25m03","title":"Lower Unit Oil Seal – Fits Yamaha 40HP 70HP 80HP 100HP 4-stroke (Replaces 2807, 93101-25M03)","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\n\u003ch2\u003eProduct Details\u003c\/h2\u003e\n\u003cp\u003eThis Lower Unit Oil Seal is designed for Yamaha 4-stroke outboard motors, specifically engineered to fit F40G (40HP), F70A (70HP), F80A\/B (80HP), and F100A\/D (100HP) models. This aftermarket propeller shaft oil seal ensures a reliable barrier against lower unit oil leaks, maintaining proper lubrication and protecting critical gearcase components.\u003c\/p\u003e\n\u003cp\u003eDirect replacement for Yamaha OEM part numbers 93101-25M03 and 2807, offering a cost-effective interchange solution without sacrificing performance.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003ePrecision-molded to OEM dimensions for proper sealing and shaft clearance\u003c\/li\u003e\n\u003cli\u003eDesigned for saltwater and freshwater marine environments\u003c\/li\u003e\n\u003cli\u003eSimple press-fit installation into lower gearcase housing\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        \u003cth\u003eNotes\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e93101-25M03\u003c\/td\u003e\n        \u003ctd\u003eProp Shaft Oil Seal\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003e2807\u003c\/td\u003e\n        \u003ctd\u003eAlternate OEM reference\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\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\u003eOEM Part No.\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eF40G\u003c\/td\u003e\n        \u003ctd\u003e40HP\u003c\/td\u003e\n        \u003ctd\u003e4-stroke\u003c\/td\u003e\n        \u003ctd\u003e93101-25M03\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eF70A\u003c\/td\u003e\n        \u003ctd\u003e70HP\u003c\/td\u003e\n        \u003ctd\u003e4-stroke\u003c\/td\u003e\n        \u003ctd\u003e93101-25M03\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eF80A\u003c\/td\u003e\n        \u003ctd\u003e80HP\u003c\/td\u003e\n        \u003ctd\u003e4-stroke\u003c\/td\u003e\n        \u003ctd\u003e93101-25M03\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eF80B\u003c\/td\u003e\n        \u003ctd\u003e80HP\u003c\/td\u003e\n        \u003ctd\u003e4-stroke\u003c\/td\u003e\n        \u003ctd\u003e93101-25M03\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eF100A\u003c\/td\u003e\n        \u003ctd\u003e100HP\u003c\/td\u003e\n        \u003ctd\u003e4-stroke\u003c\/td\u003e\n        \u003ctd\u003e93101-25M03\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr\u003e\n        \u003ctd\u003eYamaha\u003c\/td\u003e\n        \u003ctd\u003eF100D\u003c\/td\u003e\n        \u003ctd\u003e100HP\u003c\/td\u003e\n        \u003ctd\u003e4-stroke\u003c\/td\u003e\n        \u003ctd\u003e93101-25M03\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\u003eApplication\u003c\/dt\u003e\n  \u003cdd\u003ePropeller shaft oil seal for lower gearcase unit\u003c\/dd\u003e\n  \u003cdt\u003eMaterial\u003c\/dt\u003e\n  \u003cdd\u003eMarine-grade elastomer compound\u003c\/dd\u003e\n  \u003cdt\u003eFitment Type\u003c\/dt\u003e\n  \u003cdd\u003ePress-fit installation\u003c\/dd\u003e\n  \u003cdt\u003eEnvironment\u003c\/dt\u003e\n  \u003cdd\u003eSaltwater and freshwater compatible\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003ch2\u003eWhat's in the Box\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003e1 x Prop Shaft Oil Seal\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Notes\u003c\/h2\u003e\n\u003col\u003e\n\u003cli\u003eDrain lower unit gear oil completely and remove propeller assembly from shaft.\u003c\/li\u003e\n\u003cli\u003eSeparate lower unit from midsection following manufacturer service manual procedures.\u003c\/li\u003e\n\u003cli\u003eCarefully remove old seal from gearcase housing using a seal puller or appropriate pick tool without damaging the bore surface.\u003c\/li\u003e\n\u003cli\u003eClean the seal bore thoroughly, removing all residue, corrosion, or debris.\u003c\/li\u003e\n\u003cli\u003eInspect the propeller shaft for scoring, wear, or damage that may compromise the new seal.\u003c\/li\u003e\n\u003cli\u003eLightly lubricate the new seal lip and outer diameter with marine gear oil.\u003c\/li\u003e\n\u003cli\u003ePress the seal squarely into the bore using a seal driver or socket of appropriate diameter until fully seated.\u003c\/li\u003e\n\u003cli\u003eReassemble the lower unit to the midsection, ensuring proper alignment and gasket installation.\u003c\/li\u003e\n\u003cli\u003eRefill the lower unit with the manufacturer's specified gear oil to the correct level.\u003c\/li\u003e\n\u003cli\u003eReinstall propeller hardware and torque to specification.\u003c\/li\u003e\n\u003cli\u003eRun the engine briefly and inspect for leaks around the seal area.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cdetails\u003e\u003csummary\u003eHow do I know if my prop shaft seal needs replacement?\u003c\/summary\u003e\u003cp\u003eCommon signs include visible gear oil leaking from the lower unit near the propeller, milky or contaminated gear oil indicating water intrusion, or low oil levels between service intervals. Inspect during routine maintenance or if you notice oil residue on the propeller or skeg area.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cdetails\u003e\u003csummary\u003eCan I install this seal without removing the lower unit?\u003c\/summary\u003e\u003cp\u003eNo, proper installation requires complete lower unit removal from the midsection. The propeller shaft must be withdrawn from the gearcase to access and replace the seal. Attempting shortcuts risks improper seating and premature seal failure.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cdetails\u003e\u003csummary\u003eWhat tools do I need for installation?\u003c\/summary\u003e\u003cp\u003eYou'll need a seal puller or pick set for removal, a seal driver or appropriately sized socket for installation, gear oil drain pan, torque wrench, and basic hand tools for lower unit separation. A service manual for your specific engine model is highly recommended.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cdetails\u003e\u003csummary\u003eWill this seal fit both saltwater and freshwater applications?\u003c\/summary\u003e\u003cp\u003eYes, this seal is constructed from marine-grade materials designed to withstand both saltwater and freshwater environments. Ensure proper maintenance and regular lower unit oil changes to maximize seal life regardless of operating conditions.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cdetails\u003e\u003csummary\u003eHow often should I replace the prop shaft seal?\u003c\/summary\u003e\u003cp\u003eReplace the seal whenever you observe leakage, during major lower unit service or gearcase repair, or if the lower unit has been submerged beyond normal operation. Preventive replacement every 3–5 years or during propeller shaft bearing replacement is good practice for high-use engines.\u003c\/p\u003e\u003c\/details\u003e\n\n\u003cdetails\u003e\u003csummary\u003eWhat causes premature seal failure?\u003c\/summary\u003e\u003cp\u003eCommon causes include scored or damaged propeller shafts, improper installation technique, using incorrect seal drivers that damage the seal lip, debris or corrosion in the seal bore, running the lower unit with low or contaminated gear oil, and impact damage from underwater strikes.\u003c\/p\u003e\u003c\/details\u003e\n\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\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\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 against 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","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":51025914822971,"sku":"2807","price":16.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0826\/8673\/8747\/files\/s-l1600_37fc7823-fb1e-4d2a-9e4a-d33149d667f0.webp?v=1772975103","url":"https:\/\/seasierra.com\/products\/lower-unit-oil-seal-fits-yamaha-40hp-70hp-80hp-100hp-4-stroke-replaces-2807-93101-25m03","provider":"SeaSierra","version":"1.0","type":"link"}