Bellow Retainer Ring Installation Tool – Fits Mercury MerCruiser Bravo & Alpha One Gen 2
This specialized installation tool is designed for installing the aluminum retainer ring into the U-joint bellows on various Mercury MerCruiser sterndrives. It is compatible with MerCruiser Bravo One, Two, Three, Bravo X/XR/XZ series, and Alpha One Generation II sterndrives.
This tool is a direct replacement for multiple OEM and aftermarket part numbers, ensuring a precise fit for your maintenance needs.
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Application: Used to install the aluminum retainer ring into U-joint bellows.
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Material: Constructed from high-grade steel for durability and reliable performance.
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Compatibility: Fits sterndrives from 1988 to present, including Alpha One Gen 2 and all Bravo series.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Mercury |
91-818162 |
| Mercury |
818162 |
| Mercury |
43577 |
| Sierra |
18-9870 |
| Mallory |
9-79821 |
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 |
1988–Present |
91-818162 |
Heavy-duty applications |
| Mercury |
Bravo Three |
250–500+ |
4-Stroke |
1988–Present |
91-818162 |
Dual-prop configuration |
| Mercury |
Bravo X ONE, TWO, THREE |
250–500+ |
4-Stroke |
1998–2013 |
91-818162 |
Later series [0M100001-0W249999] |
| Mercury |
Bravo XZ ONE |
250–500+ |
4-Stroke |
1998–2002 |
91-818162 |
Series [0L914990-0M999999] |
| Mercury |
Bravo XR ONE |
250–500+ |
4-Stroke |
1998–2002 |
91-818162 |
Series [0L914990-0M999999] |
| Mercury |
Bravo XR ONE, THREE |
250–500+ |
4-Stroke |
1998–2009 |
91-818162 |
Series [0W240000 and up] |
| Mercury |
Bravo XR SPORTMASTER |
250–500+ |
4-Stroke |
1998–2002 |
91-818162 |
Series [0M052945-0M906877] |
| Mercury |
Bravo XR SPORTMASTER |
250–500+ |
4-Stroke |
1998–2009 |
91-818162 |
Series [0M906878 and up] |
| Mercury |
INTEGRATED TRANSOM |
250–500+ |
4-Stroke |
1998–2002 |
91-818162 |
Series [0ALL-0M052767] |
| Mercury |
INTEGRATED TRANSOM |
250–500+ |
4-Stroke |
1998–2009 |
91-818162 |
Series [0M052768 and up] |
| Mercury |
HI PERFORMANCE TRANSOM |
250–500+ |
4-Stroke |
1998–2009 |
91-818162 |
Series [0W150003 and up] |
Technical Specifications
| Specification |
Value |
| Product Type |
Drive Shaft Bellow Retainer Ring Installation Tool |
| Installation |
Used to install aluminum retainer ring into U-joint bellows |
| Housing Material |
High-grade steel |
| Dimensions |
Approximately 89 mm diameter × 25 mm height (3.5" × 1") |
| Weight |
Approximately 150 g (5.3 oz) |
| Fitting Type |
Precision-machined installation sleeve |
| Operating Temperature |
Standard ambient conditions (-10°C to 50°C / 14°F to 122°F) |
| Other Technical Attributes |
Requires driver rod for optimal performance; installs retainer rings for U-joint bellows |
Package Contents
- 1 × Bellow Retainer Ring Installation Tool (Replaces 91-818162, 43577)
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 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
Q: How do I confirm this tool fits my sterndrive?
A: This tool is compatible with MerCruiser Alpha One Gen II (1992–Present) and all Bravo series sterndrives (1988–Present), including Bravo One, Two, Three, and the X/XR/XZ series. It is a direct replacement for OEM part numbers 91-818162, 818162, and 43577. Please verify your model and part number against the compatibility charts on this page.
Q: Do I need any other tools for installation?
A: Yes, for optimal performance, this installation tool requires a driver rod to apply even pressure and properly seat the retainer ring into the bellows.
Q: Is this tool made of metal or plastic?
A: Our installation tool is manufactured from high-grade steel for maximum durability and strength, ensuring it will not deform under pressure. While some aftermarket alternatives may be made of plastic, our version is built to meet or exceed OEM specifications.
Q: OEM vs. Aftermarket?
A: 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.
Q: How fast do you ship and how much does it cost?
A: 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.
Q: What is your warranty and return policy?
A: 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.