Transom Seal Repair Kit – Fits MerCruiser Bravo I, II, III & Blackhawk Sterndrives (Replaces 30-803100T1, 8M0095485)

Transom Seal Repair Kit – Fits MerCruiser Bravo I, II, III & Blackhawk Sterndrives

This is a complete transom seal repair kit for MerCruiser Bravo I, II, and III stern drives from 1998 and newer (serial number 0B664190 and up). It also fits Blackhawk stern drives from 1994–1995 (serial number 0D469859 and up).

This kit serves as a direct replacement for multiple OEM and aftermarket part numbers, providing all the necessary components for a comprehensive transom service. It is designed to meet or exceed original equipment specifications for sealing and durability.

• Includes U-joint, exhaust, and shift cable bellows, plus gimbal bearing and necessary seals.
• Features CR Neoprene bellows with stainless steel (SS304) clips for corrosion resistance.
• Restores the integrity of the transom assembly, preventing water intrusion.

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 MerCruiser 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 Gimbal Bearing
• 1 x Gimbal Housing Seal (41802)
• 1 x U-Joint Bellow (86840A3/86840A05)
• 1 x Shift Cable Bellow (74639)
• 1 x Bell Housing Exhaust Bellow (18654A1)
• 1 x Exhaust Tube (78458A1)
• 1 x Water Hose
• 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)

Installation Guide

1. Preparation: Start by tilting the stern drive to the full "up" position and securing it. Disconnect the boat's battery.
2. Remove Drive: Detach the stern drive assembly from the bell housing according to your service manual's instructions.
3. Remove Old Components: Carefully remove the old U-joint, exhaust, and shift bellows. Inspect for and remove any old sealant or adhesive residue.
4. Extract Gimbal Bearing: Use a slide hammer and bearing puller attachment to remove the old gimbal bearing from the transom assembly.
5. Install New Bearing: Align and install the new gimbal bearing using a proper bearing driver tool. Ensure it is seated correctly and the oil hole is aligned.
6. Install New Bellows: Install the new shift cable bellow first, followed by the U-joint and exhaust bellows. Secure all bellows with the provided clamps.
7. Replace Seals: Replace the gimbal housing and oil seals included in the kit to ensure a watertight fit.
8. Reassemble: Re-attach the stern drive to the bell housing, ensuring all connections are secure.
9. Final Checks: Lower the drive and check for proper shift cable operation. Reconnect the battery and test run the engine, checking carefully for any water leaks around the transom.

Troubleshooting & FAQ

Q: How do I confirm this fits my engine?
A: This kit is designed for MerCruiser Bravo I, II, III, X, XR, and Four S models from 1998-present (serial numbers 0B664190 and up) and Blackhawk drives from 1994-1995 (serial numbers 0D469859 and up). Please verify your model and serial number range before ordering.

Q: What are the signs that my transom seal kit needs replacing?
A: Common indicators include visible cracks or dry rot on the bellows, water collecting inside the bellows, a grinding or roaring noise from the gimbal bearing (especially when turning), or stiffness in the steering and shifting mechanisms.

Q: How often should I replace my transom seals and bellows?
A: As a general maintenance guideline, bellows and seals should be inspected annually and typically replaced every 3-5 years, depending on usage (freshwater vs. saltwater) and storage conditions. The gimbal bearing should be replaced if it shows any signs of roughness or rust.

Q: OEM vs. Aftermarket?
A: 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.

Q: How fast do you ship and how much does it cost?
A: 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.

Q: What is your warranty and return policy?
A: 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.