Bellow Retainer Ring Installation Tool – Fits Mercury MerCruiser Alpha 1 Gen 2, Bravo, Blackhawk (Replaces 91-818162)
This specialized installation tool is engineered for installing the aluminum retainer ring inside the U-joint bellows. It is designed specifically for Mercury MerCruiser Alpha One Generation 2, Bravo (One, Two, Three), and Blackhawk sterndrives manufactured from 1988 to the present.
This tool is a direct replacement for several OEM and aftermarket part numbers, ensuring precise compatibility for a seamless repair or maintenance task.
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Function: Specialized tool designed to properly seat the U-joint bellows retainer ring.
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Material: Constructed from high-strength Aluminum for durability and precise fit.
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Requirements: Requires a compatible driver rod and engine alignment tool for proper use.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Mercury Marine |
91-818162 |
| Mercury Marine |
43577 |
| Sierra |
18-9870 |
| Mallory |
9-79821 / 79821 |
| HeuroFosh |
818162 |
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.
| 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 Specifications
| Specification |
Value |
| Product Type |
Drive Shaft Bellow Sleeve Installation Tool |
| Installation |
Specialized tool for installing aluminum retainer ring into U-joint bellows |
| Housing Material |
Aluminum |
| Dimensions |
Approximately 89 mm diameter x 25 mm height (3.5" x 1") |
| Weight |
Approximately 150 g (0.33 lb) |
| Fitting Type |
Precision-machined installation sleeve |
| Warranty |
1-year against manufacturing defects |
| Other Technical Attributes |
Requires driver rod and installer tool for optimal performance; engine alignment tool needed for use |
Package Contents
- 1 x Bellow Retainer Ring Installation Tool (Replaces 91-818162)
Installation Guide
- 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
How do I confirm this tool works with my sterndrive?
This tool is specifically designed for Mercury MerCruiser Alpha One Gen II, Bravo (One, Two, Three), and Blackhawk sterndrives. Cross-reference your existing part number with our list, which includes Mercury 91-818162, Sierra 18-9870, and others, to ensure a perfect match.
What other tools do I need for the installation?
For proper installation, you will need a compatible driver rod to apply even pressure and an engine alignment tool to ensure correct positioning during the process.
Is this tool made of aluminum or plastic?
Our bellow retainer ring installer is constructed from high-quality, durable aluminum to ensure longevity and a precise fit. While some aftermarket alternatives exist in plastic, our version is built for strength and repeated use.
OEM vs. Aftermarket?
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.
How fast do you ship and how much does it cost?
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.
What is your warranty and return policy?
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?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.