Transom Bellows Kit – Fits MerCruiser Bravo 1, 2, 3 & Blackhawk (Replaces 30-803100T1, 8M0095485)
Transom Bellows 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.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Transom Bellows Kit – Fits MerCruiser Bravo 1, 2, 3 & Blackhawk...
Product Details
This comprehensive MerCruiser Transom Bellows Kit is designed for the service and repair of MerCruiser Bravo I, II, and III stern drives (1998 and newer, serial number 0B664190 and up) and Blackhawk models (1994–1995, serial number 0D469859 and up). It provides all essential components for restoring the integrity of the transom assembly.
The kit serves as a direct interchange for MerCruiser OEM parts 30-803100T1 and 8M0095485, as well as aftermarket equivalents like Sierra 18-8219 and GLM 21965.
- Engineered for direct OEM replacement and fitment.
- Constructed with durable CR Neoprene bellows and SS304 stainless steel hardware.
- Includes marine-grade O-rings and a complete outdrive gasket set.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| MerCruiser | 30-803100T1 |
| MerCruiser | 8M0095485 |
| Sierra | 18-8219 |
| Sierra | 18-8212-1 |
| GLM | 21965 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit is specifically designed for the following MerCruiser stern drive models.
| Brand | Model | Years | OEM Part No. | Notes |
|---|---|---|---|---|
| MerCruiser | Bravo I | 1998–present | 30-803100T1/8M0095485 | Serial number 0B664190 & up |
| MerCruiser | Bravo II | 1998–present | 30-803100T1/8M0095485 | Serial number 0B664190 & up |
| MerCruiser | Bravo III | 1998–present | 30-803100T1/8M0095485 | Serial number 0B664190 & up |
| MerCruiser | Blackhawk | 1994–1995 | 30-803100T1/8M0095485 | Serial number 0D469859 & up |
Technical Specs
- Product Type
- Transom Bellows Service Kit
- Installation
- Direct OEM replacement
- Connection
- Direct mount to transom assembly
- Housing Material
- CR Neoprene bellows, SS304 clips and clamps
- Housing Color
- Black
- Fitting Type
- Marine stern drive transom assembly
- Other Technical Attributes
- Marine engine grade O-rings
What’s in the Box
- 1 x Gimbal Bearing with 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 Intake Hose
- 1 x Outdrive Gasket Set
- 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 Notes
- Disconnect the battery and trim the stern drive to the "trailer" position.
- Remove the stern drive unit from the transom assembly according to the manufacturer's service manual.
- Carefully remove the old bellows (U-joint, exhaust, shift cable), gimbal bearing, and all associated seals.
- Thoroughly clean all mating surfaces on the transom and bell housing, inspecting for corrosion or damage.
- Install the new gimbal bearing and seals using appropriate alignment and driver tools.
- Install the new U-joint, exhaust, and shift cable bellows, ensuring all clamps are correctly positioned and tightened securely.
- Reconnect cooling water hoses and shift linkage components.
- Reinstall the stern drive unit, using the new gasket set provided. Torque all fasteners to the specified values.
- Once assembled, check for leaks and verify proper shift and steering operation before returning to service.
Troubleshooting & FAQ
How can I tell if my existing bellows are failing?
Look for visible cracks, splits, or perishing of the rubber. Water inside the bellows (a milky appearance in the gear lube is a strong indicator) or excessive noise and vibration from the gimbal bearing area also signal a need for replacement.
Is this kit compatible with an older Bravo drive before 1998?
No, this kit is specifically for models from 1998 and newer (serial number 0B664190 and up). Older drives require a different bellows and bearing kit. Always verify your serial number before ordering.
What is the recommended replacement interval for transom bellows?
For preventative maintenance, it's wise to inspect bellows annually and replace them every 3-5 years, depending on usage (saltwater vs. freshwater) and storage conditions. A damaged bellow can lead to catastrophic failure of the gimbal bearing and U-joints.
Does this kit include the alignment tool?
No, an engine alignment tool is required for proper gimbal bearing installation but is not included in this service kit. It must be sourced separately.
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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