Sierra 18-6103A Aluminum Anode & Insert for OMC Sterndrive Transom Mount

The Sierra 18-6103A is an aluminum replacement anode and insert designed for OMC Sterndrive/Cobra transom mount applications. Constructed from high-quality aluminum alloy, this sacrificial anode is the ideal choice for boats operated in salt or brackish water environments, where it actively diverts galvanic corrosion away from vital drivetrain components.

Sierra aftermarket marine parts are engineered to meet or exceed OEM specifications, making the 18-6103A a direct, confidence-inspiring replacement for the original equipment anode. The aluminum construction offers superior performance over zinc in mixed or brackish water conditions, providing reliable corrosion protection for shafts, drive housings, and other submerged metal components.

Key Features:

• Material: Aluminum alloy — recommended for salt water and brackish water use
• Designed for OMC Sterndrive/Cobra transom mount applications
• Fits transom mounts: 2.3L and 3.0L (1987–1989) and 2.6L (1989)
• Interchangeable with: GLM 12775, OMC Stern Drive 983952 and 984547
• Aluminum variant of the Sierra 18-6103 (zinc) anode
• Meets or exceeds OEM requirements
• Includes anode and insert

Sacrificial anodes like the 18-6103A are a critical part of any corrosion protection strategy for sterndrives and should be inspected regularly and replaced when more than 50% consumed.