Bellow Retainer Ring Installation Tool – Fits Mercury MerCruiser Alpha 1 Gen 2, Bravo, Blackhawk (Replaces 91-818162)
Bellow Retainer Ring Installation Tool – Fits Mercury MerCruiser Alpha 1 Gen 2, Bravo, Blackhawk (Replaces 91-818162) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Bellow Retainer Ring Installation Tool – Fits Mercury MerCruiser Al...
Bellow Retainer Ring Installation Tool – Fits Mercury MerCruiser Alpha 1 Gen 2, Bravo, Blackhawk (Replaces 91-818162) is backordered and will ship as soon as it is back in stock.
Product Details
This specialized Bellow Retainer Ring Installation Tool is designed for installing the aluminum retainer ring inside the U-joint bellows on Mercury MerCruiser Alpha One Generation 2, Bravo, and Blackhawk sterndrives (1988–Present).
It serves as a direct replacement for multiple part numbers, including Mercury Marine 91-818162, Sierra 18-9870, and Mallory 9-79821.
- Specialized tool for installing the aluminum retainer ring into U-joint bellows.
- Constructed from high-strength aluminum for durability and precision.
- Requires a compatible driver rod for proper use.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury Marine | 91-818162 |
| Mercury Marine | 43577 |
| Sierra | 18-9870 |
| Mallory | 9-79821 |
| Mallory | 79821 |
| HeuroFosh | 818162 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This tool is compatible with a range of Mercury Marine sterndrives from 1988 to the present day.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | Alpha One Gen II | 120–300 | 4-Stroke | 1992–Present | 91-818162 | Primary application |
| Mercury | Bravo One | 250–500+ | 4-Stroke | 1988–Present | 91-818162 | High-performance drives |
| Mercury | Bravo Two | 300–500+ | 4-Stroke | 1989–Present | 91-818162 | Heavy-duty applications |
| Mercury | Bravo Three | 250–500+ | 4-Stroke | 1988–Present | 91-818162 | Dual-prop configuration |
| Mercury | Blackhawk | 300–500+ | 4-Stroke | 1994–1998 | 91-818162 | Surface drive system |
Technical Specs
- Product Type
- Drive Shaft Bellow Sleeve Installation Tool
- Application
- Specialized tool for installing aluminum retainer ring into U-joint bellows
- Housing Material
- Aluminum (Note: some aftermarket models may use PVC plastic)
- Dimensions
- Approximately 89 mm diameter x 25 mm height (3.5" x 1")
- Weight
- Approximately 150 g (0.33 lb)
- Package Dimensions
- 15 cm x 10 cm x 3 cm
- Fitting Type
- Precision-machined installation sleeve
- Operating Temperature
- Standard ambient conditions (-10°C to 50°C / 14°F to 122°F)
- Warranty
- 1-year against manufacturing defects (varies by manufacturer)
- Additional Requirements
- Requires driver rod and installer tool for optimal performance; engine alignment tool needed for use
What’s in the Box
- 1 x Bellow Retainer Ring Installation Tool (91-818162)
Installation Notes
- Ensure the sterndrive unit is safely tilted up and accessible.
- Place the new U-joint bellows onto the gimbal housing.
- Insert the aluminum retainer ring into the designated groove on the new bellows.
- Position this sleeve installation tool evenly over the retainer ring.
- Using a compatible driver rod, carefully apply pressure to drive the tool, seating the ring securely into the bellow's groove.
- Once fully seated, visually inspect the ring to confirm it is flush and evenly installed.
- Carefully remove the installation tool. The bellows is now secured.
Troubleshooting & FAQ
What sterndrive series does this tool fit?
This tool is designed for Mercury MerCruiser Alpha One Gen II, Bravo (One, Two, Three), and Blackhawk series sterndrives from 1988 to present.
Is this tool made of aluminum or plastic?
Our tool is constructed from high-strength aluminum, following the OEM specification. Some other aftermarket suppliers may offer versions made from PVC plastic, but we use aluminum for superior durability and a precise fit.
What other tools are required to use this installer?
For optimal performance, you will need a compatible driver rod to apply even pressure. It is also recommended to use an engine alignment tool during the overall bellows replacement process to ensure correct drive alignment.
How do I know the retainer ring is installed correctly?
After using the tool, perform a visual inspection. The aluminum retainer ring should be fully seated and sit flush within the bellow's groove. There should be no gaps or unevenness.
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.
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