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

Transom Seal Repair Kit – Fits MerCruiser Bravo 1, 2, 3 & Blackhawk

This transom seal repair kit is designed for MerCruiser Bravo One, Two, Three, and Blackhawk stern drives from 1988 and newer. It contains all necessary bellows, seals, gaskets, and components to completely overhaul the transom sealing system.

This kit is a direct replacement for Mercury/MerCruiser part numbers 30-803100T1 and 8M0095485.

• Complete Overhaul: Includes all required bellows, gimbal bearing, gaskets, and seals for a full transom service.
• Wide Compatibility: Fits a broad range of Bravo and Blackhawk sterndrives from 1988 to present.
• Direct Replacement: Engineered to meet or exceed OEM specifications for a precise fit and reliable function.

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 Drive Shaft Bellows (86840A05/86840A3)
• 1 x Exhaust Tube Assembly (78458A1)
• 1 x Exhaust Bellows Assembly (18654A1/8M0124227)
• 1 x Sealed Gimbal Bearing (30-862540A3/18-21006)
• 1 x Shift Cable Bellows Assembly (74639A2)
• 1 x Water Hose (32-43437)
• 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 Water Inlet Housing and Gasket

Installation Guide

1. Disconnect the battery and place the sterndrive in the full down/trailer position.
2. Remove the sterndrive assembly from the gimbal housing by disconnecting the trim rams and drive shaft.
3. Carefully cut and remove the old U-joint, exhaust, and shift cable bellows from the transom assembly.
4. Inspect the gimbal bearing. If worn, remove it using a slide hammer and bearing puller attachment.
5. Install the new gimbal bearing and oil seal, ensuring it is properly aligned and seated.
6. Install the new shift cable bellows, U-joint bellows, and exhaust bellows. Use a quality bellows adhesive to ensure a watertight seal.
7. Replace the main water inlet hose and any other included seals and gaskets.
8. Carefully reinstall the sterndrive assembly, making sure all bellows are properly seated and secured with clamps.
9. Reconnect all hoses, trim senders, limit switches, and shift components.
10. Before launching, perform a leak check in a controlled environment to ensure all seals are secure.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my specific engine?
A: Check your engine model and year against the "Compatible Engine Models" table. It is crucial to also match your sterndrive’s serial number with the ranges provided (e.g., 0B664190 & Up for Bravo drives). If unsure, use the Mercury Serial Number Guide linked above.

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 leaking into the bilge area from the transom, a stiff or noisy gimbal bearing, or difficulty shifting. Regular inspection (at least annually) is recommended.

Q: How often should I replace the bellows and gimbal bearing?
A: As a general maintenance rule, bellows should be inspected annually and replaced every 3-5 years, depending on usage and a saltwater or freshwater environment. The gimbal bearing should be replaced if it feels rough, noisy, or has any play.

Q: Is this kit the same as the original Mercury part?
A: This is an aftermarket kit designed to be a direct replacement for the OEM assembly. While the function and fit are the same, materials and some included minor hardware may vary slightly from the original MerCruiser kit.

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.