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 (Replaces 30-803100T1, 8M0095485) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Transom Seal Repair Kit – Fits MerCruiser Bravo 1, 2, 3 & Black...
Product Details
This Transom Seal Repair Kit is a comprehensive solution for overhauling the transom sealing system on MerCruiser Bravo One, Two, Three, and Blackhawk stern drives manufactured from 1988 and newer. It includes all essential components to restore a watertight seal and ensure reliable performance.
This kit serves as a direct replacement for multiple OEM and aftermarket part numbers, including Mercury/MerCruiser 30-803100T1 and 8M0095485, Sierra 18-8219, and GLM 21961.
- Direct replacement design for OEM fitment.
- Includes all essential bellows, seals, gaskets, and a gimbal bearing for a complete overhaul.
- Constructed with durable neoprene/rubber and marine-grade metal components.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury/MerCruiser | 30-803100T1 / 8M0095485 |
| Sierra | 18-8219 / 18-8212-1 |
| GLM | 21961 / 21965 |
| Mallory | 9-72903 / 9-72907 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit is designed for the following MerCruiser Bravo and Blackhawk models.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | Bravo One | Various | 4-Stroke | 1988 & Up | 30-803100T1/8M0095485 | Serial Range: 0B664190 & Up |
| MerCruiser | Bravo Two | Various | 4-Stroke | 1988 & Up | 30-803100T1/8M0095485 | Serial Range: 0B664190 & Up |
| MerCruiser | Bravo Three | Various | 4-Stroke | 1988 & Up | 30-803100T1/8M0095485 | Serial Range: 0B664190 & Up |
| MerCruiser | Blackhawk | Various | 4-Stroke | 1994–1995 | 30-803100T1/8M0095485 | Serial Range: 0D469859 & Up |
Technical Specs
- Product Type
- Transom Seal Repair Kit
- Installation
- Direct replacement
- Connection
- OEM fitment
- Housing Material
- Neoprene/rubber bellows with metal components
- Housing Color
- Black
- Shipping Dimensions
- 350 × 210 × 160 mm (13.75 × 8.25 × 6.25 in)
- Shipping Weight
- 2.54 kg (5.6 lbs)
- Fitting Type
- OEM specified
- Thread Size
- Various - includes 0.25 × 20 × 1.00 screws for water inlet housing
- Other Technical Attributes
- Complete kit for overhaul of transom sealing system
- Warranty
- OEM parts carry standard Mercury Marine warranty; aftermarket varies by manufacturer
What’s in the Box
- 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 Notes
- Disconnect the battery and remove the stern drive unit according to the manufacturer's service manual.
- Remove the old exhaust, U-joint, and shift cable bellows from the transom assembly.
- Extract the old gimbal bearing using an appropriate bearing puller tool.
- Clean all mounting surfaces on the bell housing and transom plate thoroughly, removing any old sealant or debris.
- Install the new gimbal bearing and oil seal, ensuring proper alignment.
- Install the new shift cable bellows, U-joint bellows, and exhaust bellows. Secure all clamps tightly.
- Install the new water hose and ensure all connections are secure.
- Reinstall the stern drive unit, verifying correct alignment and engagement of the driveshaft and shift cable.
- Reconnect the battery and test for proper operation and for any leaks in a controlled environment before open water use.
Troubleshooting & FAQ
How do I know if this kit fits my specific Bravo drive?
This kit is compatible with MerCruiser Bravo One, Two, and Three drives from 1988 and up (serial range 0B664190 & Up) and Blackhawk drives from 1994–1995. Always verify your drive's model, year, and serial number against our compatibility table before ordering.
What are the signs that my transom seal needs replacement?
Common signs of a failing transom seal include water in the bilge area, visible cracks or deterioration in the bellows, a stiff or grinding noise when turning the drive (indicating a bad gimbal bearing), or difficulty shifting.
How often should transom bellows be replaced?
As a preventative maintenance measure, it's recommended to inspect bellows annually and replace them every 3–5 years, depending on usage (freshwater vs. saltwater) and storage conditions. A complete kit replacement is advised if any single component fails.
Does this kit include the gimbal bearing installation tool?
No, specialized tools like a gimbal bearing puller, alignment tool, and bellows expander are required for installation and are not included in this kit.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost?
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns?
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
Payment & Security
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