{"product_id":"transom-seal-kit-fits-mercruiser-r-mr-alpha-one-gen-i-stern-drives-replaces-30-803098t1","title":"Transom Seal Kit – Fits MerCruiser R\/MR\/Alpha One Gen I Stern Drives (Replaces 30-803098T1)","description":"\u003ch2\u003eTransom Seal Kit – Fits MerCruiser R\/MR\/Alpha One Gen I Stern Drives (Replaces 30-803098T1)\u003c\/h2\u003e\n\u003cp\u003eThis transom seal kit provides the essential components needed to service MerCruiser R, MR, and Alpha One Generation I stern drives produced from \u003cstrong\u003e1983 to 1991\u003c\/strong\u003e (serial numbers 6225577 through 0D469858). It is engineered to meet or exceed OEM specifications for a reliable, leak-free seal.\u003c\/p\u003e\n\u003cp\u003eThis kit is a direct replacement for multiple industry part numbers, ensuring wide compatibility and a straightforward installation process for a complete transom reseal and gimbal bearing replacement job.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eComplete Service Kit:\u003c\/strong\u003e Includes all necessary bellows, gimbal bearing, gaskets, seals, and clamps for a full transom service.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDirect Replacement:\u003c\/strong\u003e Designed to replace Mercury Marine P\/N 30-803098T1 and other equivalent aftermarket parts without modification.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDurable Construction:\u003c\/strong\u003e Made with high-quality rubber, plastic, and metal components to withstand the harsh marine environment.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003ePart Number Cross-Reference\u003c\/h2\u003e\n\u003cp\u003eUse this table to confirm equivalent part numbers across OEM and aftermarket brands.\u003c\/p\u003e\n\u003cdiv style=\"overflow-x:auto;\"\u003e\n\u003ctable\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\u003e30-803098T1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-8205\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSierra\u003c\/td\u003e\n\u003ctd\u003e18-8217\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGLM\u003c\/td\u003e\n\u003ctd\u003e21951\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMallory\u003c\/td\u003e\n\u003ctd\u003e9-72901\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRedline\u003c\/td\u003e\n\u003ctd\u003eRL8205\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003ch2\u003eCompatible Engine Models\u003c\/h2\u003e\n\u003cp\u003eConfirm your engine model\/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial\/model: \u003ca href=\"https:\/\/jlmmarine.com\/blogs\/serial-number-guide\/mercury-outboard-serial-number-guide\" rel=\"nofollow noopener\" target=\"_blank\"\u003eMercury Serial Number Guide\u003c\/a\u003e. You can also review exploded diagrams to verify part numbers: \u003ca href=\"https:\/\/jlmmarine.com\/blogs\/diagrams\/mercury-parts-catalog\" rel=\"nofollow noopener\" target=\"_blank\"\u003eMercury Parts Diagrams \u0026amp; Catalog\u003c\/a\u003e.\u003c\/p\u003e\n\u003cdiv style=\"overflow-x:auto;\"\u003e\n\u003ctable\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\u003eMerCruiser\u003c\/td\u003e\n\u003ctd\u003eR\/MR\/Alpha One (Sterndrive)\u003c\/td\u003e\n\u003ctd\u003eN\/A\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e1983-1991\u003c\/td\u003e\n\u003ctd\u003e30-803098T1\u003c\/td\u003e\n\u003ctd\u003eSerial #s: 6225577-0D469858\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMerCruiser\u003c\/td\u003e\n\u003ctd\u003eR\/MR\/Alpha One (Transom Assembly)\u003c\/td\u003e\n\u003ctd\u003eN\/A\u003c\/td\u003e\n\u003ctd\u003e4-Stroke\u003c\/td\u003e\n\u003ctd\u003e1983-1991\u003c\/td\u003e\n\u003ctd\u003e30-803098T1\u003c\/td\u003e\n\u003ctd\u003eSerial #s: 6216687-0D469858\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eProduct Type\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eTransom Seal Kit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eInstallation\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eDirect replacement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eHousing Material\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eRubber, metal, plastic\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eHousing Color\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eBlack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOther Technical Attributes\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eFor use with exhaust tube configuration\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2\u003ePackage Contents\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e1 x Heavy Duty Gimbal Bearing (Replaces 18-2100 \/ 30-60794A4)\u003c\/li\u003e\n\u003cli\u003e1 x U-Joint Bellows (Replaces 18-2751 \/ 60932A4)\u003c\/li\u003e\n\u003cli\u003e1 x Shift Cable Bellows (Replaces 18-2753-1 or 18-2753-2 \/ 74639)\u003c\/li\u003e\n\u003cli\u003e1 x Exhaust Tube (Replaces 18-2760 \/ 78458A1) \u003cspan style=\"color:red;\"\u003eNote: This exhaust tube uses a single hose clamp on the transom side, which may result in a louder exhaust sound than the OEM dual-clamp setup.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e1 x Water Intake Hose, 3\/4\" (Replaces 18-3601 \/ 32-32461)\u003c\/li\u003e\n\u003cli\u003e1 x Water Intake Hose, 5\/8\" (Replaces 18-3602 \/ 32-41725-33)\u003c\/li\u003e\n\u003cli\u003e1 x Outdrive Mounting Gasket Kit (Replaces 18-2743 \/ 27-94996-2)\u003c\/li\u003e\n\u003cli\u003e2 x Bell Housing Gasket (Replaces 18-2840 \/ 27-35982)\u003c\/li\u003e\n\u003cli\u003e1 x O-Ring (Replaces 18-7153 \/ 25-25439)\u003c\/li\u003e\n\u003cli\u003e1 x O-Ring (Replaces 18-7117 \/ 25-35027)\u003c\/li\u003e\n\u003cli\u003e1 x O-Ring (Replaces 18-7170 \/ 25-33504)\u003c\/li\u003e\n\u003cli\u003e2 x Hose Clamp (Replaces 18-7310)\u003c\/li\u003e\n\u003cli\u003e1 x Hose Clamp (Replaces 18-7312)\u003c\/li\u003e\n\u003cli\u003e1 x Bellows Clamp (Replaces 18-7321 \/ 54-38863)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eInstallation Guide\u003c\/h2\u003e\n\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety First:\u003c\/strong\u003e Disconnect the boat's battery before starting any work.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove Drive:\u003c\/strong\u003e Carefully detach and remove the MerCruiser stern drive unit according to the manufacturer's service manual.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDisassemble Transom Components:\u003c\/strong\u003e Remove the old bellows (U-joint, shift, and exhaust), gimbal bearing, and water hoses from the transom housing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClean Surfaces:\u003c\/strong\u003e Thoroughly clean all mounting surfaces on the transom and bell housing, removing any old gasket material or sealant.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall Bearing:\u003c\/strong\u003e Use a gimbal bearing driver tool to properly install the new heavy-duty bearing into the gimbal housing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall Bellows:\u003c\/strong\u003e Install the new U-joint, shift cable, and exhaust bellows. Ensure they are correctly seated and secure all connections with the provided clamps.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall Hoses and Gaskets:\u003c\/strong\u003e Fit the new water intake hoses and place the new gaskets and O-rings in their designated positions. Use appropriate marine-grade adhesive where required.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReinstall Drive:\u003c\/strong\u003e Carefully reinstall the stern drive unit, ensuring proper alignment of the driveshaft and shift cable.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinal Checks:\u003c\/strong\u003e Reconnect the battery. Once in the water, check for any leaks around the transom assembly and test the drive for proper shifting and operation.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003ch2\u003eTroubleshooting \u0026amp; FAQ\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eHow do I confirm this kit fits my MerCruiser stern drive?\u003c\/strong\u003e\u003cbr\u003e\nThis kit is compatible with MerCruiser R, MR, and Alpha One Generation I models from 1983 to 1991. To ensure a perfect match, verify your drive's serial number falls within the range of \u003cstrong\u003e6225577 to 0D469858\u003c\/strong\u003e for sterndrives or \u003cstrong\u003e6216687 to 0D469858\u003c\/strong\u003e for transom assemblies.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the difference between this kit's exhaust setup and the original OEM part?\u003c\/strong\u003e\u003cbr\u003e\nThe exhaust tube in this kit is designed for a single hose clamp on the transom side, which is a common aftermarket configuration. This may result in a slightly louder exhaust noise compared to the original dual-clamp OEM setup, but does not affect performance.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat are the signs that my transom seal kit needs to be replaced?\u003c\/strong\u003e\u003cbr\u003e\nCommon signs of failure include water leaking into the bilge area through the transom, a roaring or grinding noise from the gimbal bearing when turning the wheel, or visible cracks and deterioration in the U-joint or shift bellows.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs everything I need for the job included in this kit?\u003c\/strong\u003e\u003cbr\u003e\nThis kit provides a comprehensive set of bellows, the gimbal bearing, gaskets, O-rings, and clamps needed for a typical transom service. You will still need appropriate marine-grade sealant\/adhesive and standard mechanic's tools for installation.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOEM vs. Aftermarket?\u003c\/strong\u003e\u003cbr\u003e\nThis listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow fast do you ship and how much does it cost?\u003c\/strong\u003e\u003cbr\u003e\nWe offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is your warranty and return policy?\u003c\/strong\u003e\u003cbr\u003e\nThis product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused \u0026amp; in original condition); please see our policy page or reach out for instructions.\u003c\/p\u003e\n\u003ch2\u003eImportant Notes\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eVerify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.\u003c\/li\u003e\n\u003cli\u003eThis product is an aftermarket replacement part and is not an OEM component.\u003c\/li\u003e\n\u003cli\u003eProfessional installation is recommended to ensure safety and optimal performance.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWhy Choose JLM MARINE?\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuality Assured:\u003c\/strong\u003e As a trusted manufacturer for over 20 years, we supply top marine brands globally.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFast Global Shipping:\u003c\/strong\u003e Free delivery worldwide in 5–15 days.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDirect from Manufacturer:\u003c\/strong\u003e Competitive pricing without compromising quality.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"JLM Marine","offers":[{"title":"Default Title","offer_id":49568852902201,"sku":"17B3005","price":81.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0885\/0433\/6697\/files\/Transom_Seal_Service_Kit_for_MerCruiser_Alpha_one_Gen_1_with_Gimbal_Bearing_U_Joint_and_Exhaut_Bellows_______30-803097T1_-_JLM_MARINE-8287613.jpg?v=1755051949","url":"https:\/\/jlmmarine.com\/products\/transom-seal-kit-fits-mercruiser-r-mr-alpha-one-gen-i-stern-drives-replaces-30-803098t1","provider":"JLM Marine Boat Parts Limited","version":"1.0","type":"link"}