Sierra Anode Kit 18-6158M, Magnesium, for Mercruiser Alpha One Gen 2

The Sierra Anode Kit 18-6158M is a magnesium sacrificial anode kit designed to protect the drive and running gear of Mercruiser Alpha One Gen 2 outdrives from galvanic corrosion. Magnesium anodes are the correct material choice for boats operated in freshwater, where the metal's higher reactivity provides the level of sacrificial protection needed to keep aluminum and steel drive components from corroding. As the anode kit corrodes over time in place of surrounding metal parts, it should be inspected regularly and replaced once significantly worn down, which helps prevent costly damage to the drive unit, propeller shaft, and other submerged hardware.

This kit is sold as a complete set (1 count, 1 item) so boat owners have everything needed for a full anode replacement in one purchase. It is manufactured by Sierra, a long-established supplier of marine replacement parts, and is intended for routine maintenance as part of a regular corrosion-protection schedule.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-6158M
• Material: Magnesium
• Unit Count: 1.0 Count
• Number of Items: 1
• Included Components: Anode Kit (Magnesium)
• Weight: 1.85 pounds
• UPC: 808282277260

Fitment

• Mercruiser Alpha One Gen 2 drives

Replaces (OEM)

• No OEM cross-reference numbers available for this part.

Frequently Asked Questions

What is the Sierra 18-6158M anode kit made of? The Sierra 18-6158M anode kit is made of magnesium, which is the recommended anode material for boats run primarily in freshwater.

What does this anode kit fit? The Sierra 18-6158M anode kit is designed for Mercruiser Alpha One Gen 2 drives.

How many anodes come in the 18-6158M kit? This kit is sold as a complete set, listed as 1 count with 1 item included, providing a full anode kit in a single purchase.

Why choose magnesium instead of zinc or aluminum anodes? Magnesium is more chemically reactive than zinc or aluminum, so it is the correct choice for freshwater use on the Sierra 18-6158M kit, where zinc anodes may not corrode fast enough to fully protect the drive.

How much does the Sierra 18-6158M anode kit weigh? The Sierra 18-6158M anode kit weighs 1.85 pounds.

How do I know when to replace the anodes in this kit? Anodes in the Sierra 18-6158M kit should be inspected regularly and replaced once they have visibly worn down, since a depleted anode can no longer protect the surrounding metal drive components from corrosion.

Is the Sierra 18-6158M an OEM or aftermarket part? The 18-6158M is a Sierra-branded replacement anode kit manufactured by Sierra for use on Mercruiser Alpha One Gen 2 drives.

Can I use the 18-6158M magnesium kit in saltwater? The Sierra 18-6158M kit is a magnesium anode kit, and magnesium is generally recommended for freshwater use rather than saltwater, where zinc anodes are typically preferred.

What is included when I order the 18-6158M kit? Ordering the Sierra 18-6158M provides one complete anode kit (magnesium), listed as 1 count and 1 item, ready for installation on a Mercruiser Alpha One Gen 2 drive.

Does the Sierra 18-6158M come with a warranty? No warranty is listed for the Sierra 18-6158M anode kit.