MerCruiser Alpha 1 Gen 2 Transom Bellows Repair Kit – Fits MerCruiser Alpha One Generation 2 Stern Drives (Replaces 30-803099T1)

MerCruiser Alpha 1 Gen 2 Transom Bellows Repair Kit – Fits MerCruiser Alpha One Generation 2 Stern Drives (Replaces 30-803099T1)

This transom bellows repair kit fits MerCruiser Alpha One Generation 2 stern drives manufactured from approximately 1991 and up, specifically those with serial numbers starting from 0D469859 and later. It is designed for use with outboard stern drives and provides marine-grade materials resistant to water, oil, and fuel.

Direct replacements include Mercury part numbers 30-803099T1 and 803099T1, as well as aftermarket equivalents from GLM (21960) and Sierra (18-8206).

• Includes U-Joint, Exhaust, and Shift Cable Bellows Assemblies
• Compatible with various MerCruiser Alpha One Gen 2 models
• Installation via transom mount with clamp-style fittings

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1  U-Joint Bellows Assembly (816431A1)
• 1  Exhaust Bellows Assembly (18654A1/8M0124227)
• 1  Bearing Assembly (30-862540A3/30-879194A01/30-8M2010910)
• 1  Shift Cable Bellows Assembly (74639A2)
• 1  Water Hose (32-4172533/32-8M0062309/32-8M0109048)
• 1  Alpha Outdrive Mounting Gasket Kit (27-94996Q2/27-8M0091545)

Installation Guide

Ensure the engine is turned off and cooled before beginning installation. Remove the old bellows assemblies carefully, inspecting the surrounding area for damage. Clean the transom mount surfaces thoroughly to ensure a secure seal. Position the new U-Joint bellows into place and secure it with the provided clamps. Install the exhaust bellows assembly, aligning it properly to avoid exhaust leaks. Fit the bearing assembly and tighten clamps to manufacturer torque specifications. Attach the shift cable bellows assembly carefully, ensuring smooth cable movement. Connect the water hose and check for proper routing without kinks. Install the Alpha outdrive mounting gasket kit, verifying correct positioning. Double-check all clamps and hoses for security. Start the engine and inspect for leaks or unusual noises around the installation area. Make final adjustments if necessary and confirm proper function before use.

Troubleshooting & FAQ

• How do I confirm this fits my engine? Check your engine’s serial number against the compatible ranges listed in the product details or consult the Mercury Serial Number Guide linked above.
• What are the differences versus OEM parts? This is an aftermarket replacement built to OEM specifications with marine-grade materials and quality controls in an ISO9002-certified facility.
• How often should I replace the transom bellows? Inspect regularly for cracks or leaks and replace as needed based on wear or damage to prevent water intrusion and corrosion.
• What are common signs of failure? Water leaks near the transom, exhaust leaks, or a rough shifting cable can indicate bellows damage.
• OEM vs. Aftermarket? This 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.
• How fast do you ship and how much does it cost? We offer fast global shipping15 days worldwideand standard shipping is free. Expedited options are available at checkout depending on your location.
• What is your warranty and return policy? This 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 & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify 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.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 515 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.