Sierra 18-6154M Magnesium Anode Kit, Interchangeable with Mercruiser 888760Q04, Fits Bravo III (2004 and Newer)

The Sierra 18-6154M is a magnesium anode kit built for Mercruiser Bravo III stern drives (2004 and newer). Magnesium anodes are the correct sacrificial metal choice for boats operated in freshwater, where a zinc anode will not corrode fast enough to properly protect the drive's underlying metal components. As the anode kit corrodes in place of the drive's aluminum and steel parts, it prevents galvanic corrosion from damaging the stern drive housing, gears, and other submerged metal components.

This kit is interchangeable with Mercruiser Stern Drive part number 888760Q04, so it installs as a direct replacement on applicable Bravo III drives without modification. The components are machined for precise fit and are built from high-quality magnesium material for reliable sacrificial performance. Regular anode replacement is a routine part of stern drive maintenance and helps extend the service life of the drive unit by stopping corrosion before it reaches critical components.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-6154M
• Material: Magnesium
• For Use With: Mercruiser Bravo III stern drives (2004 and newer)
• Interchangeable With: Mercruiser 888760Q04
• Weight: 2.19 pounds
• Product Dimensions: 0.39 x 0.39 x 0.39 inches
• Fit Type: Universal Fit
• UPC: 808282277239

Fitment

• Mercruiser Bravo III stern drives, 2004 and newer

Replaces (OEM)

• 888760Q04

Frequently Asked Questions

What is the Sierra 18-6154M anode kit made of? The Sierra 18-6154M anode kit is made of magnesium, which is the correct sacrificial metal for stern drives operated primarily in freshwater.

Which stern drives does the 18-6154M anode kit fit? This kit is built for Mercruiser Bravo III stern drives, 2004 and newer.

Does the Sierra 18-6154M replace an OEM Mercruiser part? Yes, the Sierra 18-6154M is interchangeable with Mercruiser Stern Drive part number 888760Q04.

Should I use magnesium or zinc anodes on my Bravo III drive? Magnesium anodes like the 18-6154M kit are recommended for freshwater use because they corrode at a rate fast enough to properly protect the drive; zinc anodes are typically used in saltwater instead.

How much does the 18-6154M anode kit weigh? The Sierra 18-6154M magnesium anode kit weighs 2.19 pounds.

Is the 18-6154M a genuine Sierra part or an aftermarket copy? The 18-6154M is a genuine Sierra International part, sold as a direct interchange for Mercruiser Stern Drive part 888760Q04.

Why do anodes need to be replaced regularly on a stern drive? Anodes such as the 18-6154M kit are sacrificial metal components that corrode in place of the drive's aluminum and steel parts, so they must be replaced once significantly corroded to keep protecting the Bravo III drive from galvanic corrosion.

What are the dimensions of the 18-6154M anode kit components? The Sierra 18-6154M anode kit measures 0.39 x 0.39 x 0.39 inches per component.

Can the 18-6154M be used in saltwater? The 18-6154M is a magnesium anode kit, which is intended for freshwater use on Bravo III stern drives; saltwater applications typically call for a zinc anode instead.

Is installation of the 18-6154M anode kit straightforward? The 18-6154M anode kit is machined for a precise fit as a direct replacement for Mercruiser 888760Q04 on Bravo III drives, allowing installation without modification.