Transom Bellows Kit – Fits MerCruiser Bravo 1, 2, 3 & Blackhawk Sterndrives (Replaces 30-803100T1, 8M0095485)

Transom Bellows Kit – Fits MerCruiser Bravo 1, 2, 3 & Blackhawk Sterndrives

This transom bellows repair kit provides a complete solution for servicing MerCruiser Bravo and Blackhawk sterndrives. It is engineered to fit MerCruiser Bravo I, II, and III models from 1988 and newer (serial number 0B664190 and up) and MerCruiser Blackhawk models from 1994-1995 (serial number 0D469859 and up).

This assembly is a direct replacement for multiple OEM and aftermarket part numbers, including Mercury/MerCruiser 30-803100T1 and 8M0095485, ensuring OEM fitment and performance. The components are made from high-grade neoprene rubber and durable metal to withstand the harsh marine environment.

• Includes all necessary bellows, gimbal bearing, gaskets, and seals for a comprehensive overhaul.
• Designed for direct, OEM-fit installation without modification.
• Materials selected for longevity and resistance to saltwater, oil, and UV exposure.

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 x U-Joint Bellow (Replaces 86840A3/86840A05)
• 1 x Exhaust Bellow (Replaces 18654A1)
• 1 x Shift Cable Bellow (Replaces 74639)
• 1 x Exhaust Tube (78458A1)
• 1 x Water Intake Hose
• 1 x Gimbal Bearing (Replaces 30-60792A4)
• 1 x Gimbal Housing Oil Seal (16755Q1)
• 1 x Gimbal Housing Seal (41802)
• 1 x Insert Driver (41674)
• 1 x Lever (45518A3)
• 1 x Guide (43433)
• 1 x Insert (14705)
• 1 x Shift Cable Wrapping (38473)
• 1 x Outdrive Gasket Set

Installation Guide

1. Safety First: Disconnect the boat’s battery and ensure the sterndrive is in the full down position before starting.
2. Remove Sterndrive: Detach the sterndrive unit from the gimbal housing by removing the main mounting nuts and hydraulic trim rams.
3. Remove Old Components: Carefully cut away and remove the old u-joint, exhaust, and shift cable bellows. Remove the old gimbal bearing and associated seals.
4. Clean Surfaces: Thoroughly clean all mounting surfaces on the transom assembly and gimbal housing, removing any old sealant or corrosion.
5. Install Bearing and Seals: Press the new gimbal bearing into the gimbal housing using an appropriate driver tool. Install the new gimbal housing oil seal.
6. Install Bellows: Install the new shift cable bellow first, followed by the exhaust and u-joint bellows. Secure all clamps tightly.
7. Connect Hoses: Attach the new water intake hose and ensure all connections are secure.
8. Reinstall Sterndrive: Apply a new gasket from the kit and carefully guide the sterndrive back into place. Secure it with the mounting hardware.
9. Final Checks: Torque all fasteners to the manufacturer's specified values. Reconnect the hydraulic trim rams and battery.
10. Test Operation: Once the boat is in the water, check for any leaks around the transom assembly. Test steering and shifting for proper operation.

Troubleshooting & FAQ

How do I confirm this kit fits my engine?
The most reliable way is to verify your sterndrive model and serial number. This kit fits MerCruiser Bravo I, II, & III models (1988+, serial 0B664190+) and Blackhawk models (1994-1995, serial 0D469859+). Cross-reference your existing part numbers with those listed in the compatibility table.

What are the signs that my transom bellows need replacing?
Common signs of failure include water leaking into the boat's bilge area, visible cracks or holes in the rubber bellows, or corrosion on the u-joints and gimbal bearing. You might also notice stiffness in your steering or difficulty shifting gears, which could indicate a problem with the shift cable bellow.

How often should I replace my sterndrive bellows?
As a preventative maintenance measure, it is recommended to inspect your bellows annually for any signs of cracking, drying, or damage. A full replacement is advised every 3-5 years, depending on usage and whether the boat is stored in or out of the water.

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 shipping—typically 5–15 days worldwide—and 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 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.