{"product_id":"seasierra-upper-unit-seal-kit-for-mercruiser-alpha-one-gen-ii-88397a1-oem-fit-o-rings-oil-seals-gaskets","title":"SeaSierra Upper Unit Seal Kit for Mercruiser Alpha One Gen II 88397A1 — OEM-fit O-rings, oil seals \u0026 gaskets","description":"\u003cstrong\u003eSeaSierra 88397A1 Upper Unit Seal Kit is a complete replacement seal set engineered to restore and protect the upper unit on Mercruiser Alpha One Gen II stern drives.\u003c\/strong\u003e\n\n\u003cp\u003eIf your Mercruiser Alpha One Gen 2 stern drive is leaking or due for preventative maintenance, this SeaSierra upper unit seal kit gathers the exact O-rings, oil seals and gaskets needed to rebuild the upper gearcase area. The kit is supplied to match OEM part numbers and fits Alpha I Gen II models produced across the 1991–1996+ serial ranges. Each component is selected to replicate form and fit so you can replace worn seals without sourcing multiple parts individually.\u003c\/p\u003e\n\n\u003ch3\u003eWhich models and years does this SeaSierra kit fit?\u003c\/h3\u003e\n\u003cp\u003eThis kit is compatible with Mercruiser Alpha I Gen II applications. It covers serial ranges and later production blocks commonly serviced in the field, making it suitable for many Alpha One Gen 2 stern drives.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFits Mercruiser Alpha I Gen II 1991–1995 (serial 0D469859–0F679999)\u003c\/li\u003e\n  \u003cli\u003eAlso compatible with 1996 and newer units (serial 0F680000 and up)\u003c\/li\u003e\n  \u003cli\u003eDirect replacement for OEM 26-88397A1 \/ 88397A1\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat parts are included in the 88397A1 upper unit seal kit?\u003c\/h3\u003e\n\u003cp\u003eThe SeaSierra kit contains all the small seals and gaskets typically replaced during upper unit service so you don’t miss hidden leaks. Components are packed to simplify a single maintenance job instead of multiple part orders.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eO-rings: 25-25439, 25-35027, 25-35984, 25-70937, 25-32546\u003c\/li\u003e\n  \u003cli\u003eOil seals: 26-32080, 26-37259 and upper seal 26-88397\u003c\/li\u003e\n  \u003cli\u003eDrain screw gasket(s) 12-19183 \/ 12-20260 and seal ring gasket 26-45577\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does this kit compare with OEM and other aftermarket parts?\u003c\/h3\u003e\n\u003cp\u003eSeaSierra supplies parts that match OEM dimensions and mating surfaces but at aftermarket value. The kit replaces known OEM numbers and is also cross-referenced to Mallory, GLM and Sierra equivalents, allowing straightforward substitution during repairs.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eReplaces OEM 26-88397A1 \/ 88397A1\u003c\/li\u003e\n  \u003cli\u003eCross-references Mallory 9-74302, GLM 87501, Sierra 18-2644\u003c\/li\u003e\n  \u003cli\u003eProduced and packaged by SeaSierra with decades of marine parts experience\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat should I prepare before installing the upper unit seal kit?\u003c\/h3\u003e\n\u003cp\u003eGather basic tools, a clean workspace and the service manual for torque and disassembly steps to ensure correct installation. Inspect mating surfaces, shafts and bearings—seals only stop leaks when installed on sound hardware.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eService manual or factory torque specs for your Alpha One Gen II\u003c\/li\u003e\n  \u003cli\u003eAppropriate seal drivers, clean rags and compatible gear lube\u003c\/li\u003e\n  \u003cli\u003eCheck shafts and bearing condition; replace if scored or worn\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: The SeaSierra 88397A1 Upper Unit Seal Kit is intended for boat owners, marine mechanics and DIY technicians maintaining Mercruiser Alpha One Gen 2 stern drives. If you’re performing upper gearcase service, stopping leaks, or doing scheduled preventive maintenance on 1991–1996+ Alpha I Gen II units, this kit supplies the matching seals and gaskets to complete the job in one order.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does this kit replace the OEM 26-88397A1?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes — SeaSierra 88397A1 is a direct replacement for OEM 26-88397A1 and matches common cross-reference numbers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Will this fit my Alpha One Gen II from 1994?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes — the kit fits Mercruiser Alpha I Gen II models including 1991–1995 serial ranges and 1996 and up.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":48085720596638,"sku":"B0DLT19TG5","price":42.94,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/seasierra-upper-unit-seal-kit-front-packaging.jpg?v=1785876993","url":"https:\/\/northtrailauto.ca\/products\/seasierra-upper-unit-seal-kit-for-mercruiser-alpha-one-gen-ii-88397a1-oem-fit-o-rings-oil-seals-gaskets","provider":"North Trail Auto","version":"1.0","type":"link"}