Transom Bellows Repair Kit – Fits MerCruiser Alpha One Gen 1, R, MR & SS Sterndrives (Replaces 30-803097T1)
Transom Bellows Repair Kit – Fits MerCruiser Alpha One Gen 1, R, MR & SS Sterndrives (Replaces 30-803097T1) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Transom Bellows Repair Kit – Fits MerCruiser Alpha One Gen 1, R, MR...
Product Details
This complete Transom Bellows Repair Kit is designed for MerCruiser R, MR, Alpha One (Gen 1), and Alpha One SS sterndrive models manufactured from 1983 to 1990. It provides all the necessary seals, bellows, bearings, and gaskets for a comprehensive transom service, ensuring a secure and water-tight seal for your sterndrive assembly.
This kit serves as a direct replacement for multiple OEM and aftermarket part numbers, including Mercury/MerCruiser 30-803097T1, Sierra 18-2601-1, and GLM 21950, offering a reliable alternative for maintenance and repairs.
- Includes all essential components for a full bell housing and gimbal bearing service.
- Bellows are constructed from durable neoprene rubber with stainless steel clamping hardware.
- Installation requires removal of the engine and sterndrive unit.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury/MerCruiser | 30-803097T1 |
| Sierra | 18-2601-1 |
| Sierra | 18-8213 |
| GLM | 21950 |
| AMIC | 32A40 |
| Mallory | 9-72902 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For MerCruiser models, please verify your sterndrive's serial number to ensure correct fitment as specified in the notes.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | R | Various | Both | 1983–1990 | 30-803097T1 | Serial #6225577 & up |
| MerCruiser | MR | Various | Both | 1983–1990 | 30-803097T1 | Serial #6225577 & up |
| MerCruiser | Alpha One (Gen 1) | Various | Both | 1983–1990 | 30-803097T1 | Serial #6225577 & up |
| MerCruiser | Alpha One SS | Various | Both | 1986–1989 | 30-803097T1 | Serial #0A545004 & up |
Technical Specs
- Product Type
- Transom Bellows/Seal Repair Kit
- Installation
- Direct replacement, requires engine/drive removal
- Housing Material
- Neoprene rubber (bellows) with stainless steel components
- Weight
- 2.27 kg (5 lbs) approximate
- Connection
- OEM fitment to transom assembly
- Fitting Type
- Stainless steel hose clamps
- Warranty
- Varies by manufacturer (typically 1 year)
- Other Technical Attributes
- Includes complete bell housing and gimbal bearing service components
What’s in the Box
- 1 x U-Joint Bellows with clamps (60932A4)
- 1 x Exhaust Bellows with clamps (18654A1)
- 1 x Shift Cable Bellows with clamps (74639)
- 1 x Gimbal Bearing (30-60792A4)
- 1 x Water Hose 3/4" (32-41725)
- 1 x Water Hose 5/8" (32-32461)
- 1 x Gasket Kit (27-94996T2) including:
- 1 x Bell Housing Gasket
- 1 x O-Ring (25-33504)
- 1 x O-Ring (25-35027)
- 2 x O-Rings (25-25439)
- 1 x Shift Cable Guide (43433)
- 1 x Shift Cable Insert (14705)
- 1 x Shift Cable Wrapping (38473)
- 1 x Bell Housing Shaft Lever (45518A3)
- 1 x Gimbal Housing Oil Seal (26-88416)
- 1 x Gimbal Housing Seal (41802)
Installation Notes
- Disconnect the battery and follow all safety precautions before starting work.
- Remove the sterndrive unit from the transom assembly according to the manufacturer's service manual.
- Remove the engine from the engine bay to gain access to the bell housing.
- Carefully detach the old bellows, gimbal bearing, hoses, and seals from the transom assembly.
- Clean all mounting surfaces thoroughly to remove old sealant, corrosion, and debris.
- Install the new gimbal bearing using an appropriate bearing driver.
- Install the new bellows (U-joint, exhaust, shift cable) and secure them with the provided clamps. Ensure all seals are correctly seated.
- Install all new gaskets, o-rings, and water hoses included in the kit.
- Reinstall the bell housing and engine, torquing all fasteners to the manufacturer's specifications.
- Reinstall the sterndrive, ensuring the shift cable and driveshaft are correctly aligned.
- Once assembled, check for leaks in a controlled environment before full operation.
- It is highly recommended to consult a qualified marine mechanic and your specific service manual for detailed procedures.
Troubleshooting & FAQ
How do I know if my transom bellows need replacing?
Common signs of failure include visible cracks or tears in the rubber, water entering the bilge area (especially when turning or trimming the drive), or a grinding/roaring noise from the gimbal bearing, which indicates water intrusion and bearing failure.
Will this kit fit an Alpha One Gen 2 drive?
No, this kit is specifically for the models listed, including Alpha One Gen 1 (1983–1990). Gen 2 drives use different components and require a different service kit.
Is removing the engine absolutely necessary for this installation?
Yes, for a complete service that includes replacing all components in this kit, such as the gimbal bearing and bell housing gaskets, removal of the engine is required to access the transom assembly.
What is the recommended replacement interval for these components?
Preventative replacement is recommended every 3-5 years for boats used in saltwater and 5-7 years for freshwater use, depending on usage and storage conditions. Always perform an annual inspection for cracking or wear.
What is the difference between this and an OEM kit?
Our aftermarket kit is designed to meet or exceed OEM specifications for fit, form, and function, using comparable high-quality materials. It offers a cost-effective solution for transom repair without compromising on durability.
My serial number is close but doesn't match the range. Will it fit?
It is critical to match the serial number range exactly as specified. MerCruiser made changes at specific serial number breaks. If your number is outside the listed range, this kit may not be compatible. Please verify before ordering.
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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