{"product_id":"seasierra-outboard-gearcase-seal-kit-for-johnson-evinrude-75-300hp-5006373-complete-lower-unit-seals-gaskets","title":"SeaSierra Outboard Gearcase Seal Kit for Johnson Evinrude 75–300HP (5006373) — Complete lower-unit seals \u0026 gaskets","description":"\u003cp\u003e\u003cstrong\u003eThe SeaSierra 5006373 gearcase seal kit is a complete lower-unit seal and gasket set engineered to restore water-tight performance for Johnson and Evinrude 75–300HP outboards with mechanical shift gearcases.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIf your outboard lower unit leaks oil, draws water into the gearcase, or needs routine overhaul, this SeaSierra kit gathers the common oil seals, O-rings, gaskets, bearings and service hardware you’ll need to rebuild V4, V6 and V8 engines made from 1985–2005. It replaces multiple OEM part numbers so you can service a wide range of Johnson and Evinrude models without hunting individual components.\u003c\/p\u003e\n\n\u003ch3\u003eWhich engines and years will this kit fit?\u003c\/h3\u003e\n\u003cp\u003eThis kit is designed for Johnson and Evinrude outboards rated from 75HP up to 300HP with mechanical shift lower units. It supports V4, V6 and V8 configurations produced between 1985 and 2005, covering many common mid- and high-horsepower models.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCovers 75–300HP models including 80, 85, 90, 100–175, 185–300HP ranges.\u003c\/li\u003e\n  \u003cli\u003eCompatible with mechanical-shift gearcases on V4\/V6\/V8 engines.\u003c\/li\u003e\n  \u003cli\u003eWorks as a direct replacement for OEM numbers like 5006373 and several associated seals.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat components are included to complete a lower-unit service?\u003c\/h3\u003e\n\u003cp\u003eThe SeaSierra 5006373 kit bundles the typical sealing parts and key small hardware used in a lower-unit overhaul so you won’t need to source many items separately. It focuses on oil seals, O-rings, gaskets, and bearing housing parts to restore proper sealing and drainage.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eMultiple oil seals and upper driveshaft seal for shaft and gearcase openings.\u003c\/li\u003e\n  \u003cli\u003eO-rings and bearing-housing O-ring to renew internal sealing surfaces.\u003c\/li\u003e\n  \u003cli\u003eWater pump gasket, shift cover gasket, fill\/drain screws, washers, and bearing housing parts.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does installing this kit help my boat’s performance?\u003c\/h3\u003e\n\u003cp\u003eReplacing degraded seals and gaskets prevents oil loss and water intrusion into the gearcase, which protects gears and bearings from corrosion and wear. Fresh seals also maintain correct lubrication and pressure inside the lower unit for reliable shifting and quieter operation.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003ePrevents gearbox contamination by keeping oil in and water out.\u003c\/li\u003e\n  \u003cli\u003eReduces risk of bearing and gear damage from water intrusion.\u003c\/li\u003e\n  \u003cli\u003eRestores reliable shaft sealing and fill\/drain hardware function.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat should I know before ordering and installing this kit?\u003c\/h3\u003e\n\u003cp\u003eThis kit is intended for do-it-yourself mechanics and professional technicians familiar with lower-unit tear-down and reassembly. Verify engine model, year range and mechanical-shift gearcase before purchase; some repairs may require additional bearings, seals or specialized tools not included in the kit.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eConfirm compatibility with your engine’s model\/year and mechanical shift type.\u003c\/li\u003e\n  \u003cli\u003eInspect internal gearcase components during service—replace worn bearings or gears as needed.\u003c\/li\u003e\n  \u003cli\u003eUse proper torque specs, sealants and grease when reinstalling components for a long-lasting repair.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho this kit is for: SeaSierra’s 5006373 outboard gearcase seal kit suits boat owners, marina technicians, and DIYers maintaining Johnson or Evinrude outboards from 75HP to 300HP that use mechanical-shift gearcases. Choose this kit when you need a comprehensive set of common seals, O-rings, gaskets and small hardware to address leaks, carry out routine lower-unit service, or prepare an engine for extended storage or heavy use on the water.\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 OEM part 5006373?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. The SeaSierra 5006373 kit is designed as a replacement for OEM 5006373 and multiple related seal numbers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Will this fit my 2000 Johnson 115HP outboard?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: If your 2000 Johnson 115HP has a mechanical-shift gearcase and is a V4\/V6\/V8 configuration from 1985–2005, this kit should be compatible.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"SeaSierra","offers":[{"title":"Default Title","offer_id":48084115751070,"sku":"B0DPDZG8Q2","price":81.48,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/seasierra-front-package-5006373.jpg?v=1785846710","url":"https:\/\/northtrailauto.ca\/products\/seasierra-outboard-gearcase-seal-kit-for-johnson-evinrude-75-300hp-5006373-complete-lower-unit-seals-gaskets","provider":"North Trail Auto","version":"1.0","type":"link"}