Bellow Sleeve / Retainer Ring Installation Tool – for Mercury MerCruiser Alpha One Gen II and Bravo (Replaces OEM 91-818162)

Product Details

This aftermarket bellow sleeve and retainer ring installation tool is designed to install the aluminum sleeve or retainer ring in the U-joint or exhaust bellows of compatible Mercury MerCruiser sterndrives. Catalog references identify this application for Alpha One Gen II and Bravo drive units.

The tool is listed as a replacement for Mercury Marine OEM tool number 91-818162. The corresponding Sierra reference is 18-9870.

• Installs the aluminum sleeve or retainer ring in compatible sterndrive bellows.
• Designed for Mercury MerCruiser Alpha One Gen II and Bravo applications.
• Helps apply even pressure around the ring during installation.
• Use with the appropriate driver rod or pressing equipment for the specific service procedure.

Part Number Matrix

Use the following references to compare this aftermarket tool with documented manufacturer and aftermarket catalog numbers. Part-number references do not replace confirmation of the drive-unit application.

Engine & Model Compatibility

This is a sterndrive service tool rather than an engine-specific component. Confirm the drive-unit generation and the required sleeve or retainer-ring procedure before ordering.

Technical Specs

Product Type

Bellow sleeve and retainer ring installation tool

Primary Application

Installing the aluminum sleeve or retainer ring in compatible Mercury MerCruiser sterndrive bellows

Compatible Drive Series

Mercury MerCruiser Alpha One Gen II and Bravo

OEM Reference

Mercury Marine 91-818162

Aftermarket Reference

Sierra 18-9870

Tool Function

Positions over the sleeve or ring and transfers installation pressure evenly during the service procedure

Additional Equipment

A compatible driver rod or suitable pressing equipment may be required; follow the applicable service instructions

What’s in the Box

• 1 x Bellow sleeve and retainer ring installation tool

Note: A driver rod, pressing tool, bellows, sleeve, and retainer ring are not included unless specifically listed with your order.

Installation Notes

1. Verify that the sterndrive is supported safely and that the bellows service area is accessible.
2. Confirm that the replacement bellows and the sleeve or retainer ring are correct for the drive-unit application.
3. Fit the bellows according to the applicable service procedure.
4. Place the aluminum sleeve or retainer ring in the correct position on the bellows.
5. Position the installation tool squarely over the sleeve or ring.
6. Use a compatible driver rod or pressing arrangement to apply controlled, even pressure. Do not strike the tool in a way that could damage the bellows or ring.
7. Inspect the installed sleeve or ring to confirm that it is fully seated, even, and free of gaps or distortion.
8. Remove the tool carefully and complete the remaining bellows installation steps according to the manufacturer’s service instructions.

Troubleshooting & FAQ

Safety & Important Information

• Verify the drive-unit series, bellows design, and sleeve or retainer-ring procedure before purchase and installation.
• Use appropriate eye protection and support the sterndrive securely during service.
• Apply pressure in a controlled manner and stop if the tool, ring, sleeve, or bellows is not aligned correctly.
• Professional installation is recommended when the applicable service procedure or required equipment is unfamiliar.

About Sea Sierra

• Marine service tools selected for practical sterndrive maintenance and repair applications.
• Clear aftermarket reference information to help compare tools with documented OEM and catalog numbers.
• Product descriptions are written to distinguish included items from separately required service equipment.