Sierra 18-3757 Propeller Nut Spacer for Mercury Outboards

The Sierra 18-3757 propeller nut spacer is a precision-engineered component designed to provide essential clearance and stability between the propeller nut and gearcase on Mercury outboard motors. This marine-grade spacer prevents galling, reduces wear on critical components, and maintains optimal propeller alignment during high-speed operation or rough water conditions.

Key Features:

• Specifically contoured design distributes torque evenly to avoid stress points
• Corrosion-resistant construction withstands saltwater exposure, UV rays, and constant submersion
• Precision fit matches OEM specifications for seamless integration
• Prevents metal-on-metal contact and reduces vibration during operation
• Shields mating surfaces from direct contact, extending component life
• Lightweight design adds negligible weight to preserve balance and fuel efficiency

Designed as a direct aftermarket replacement for Mercury outboard models requiring a prop nut spacer washer. Installation is straightforward with basic tools, typically taking just minutes to complete. This spacer should be inspected during annual servicing and replaced if any pitting or deformation is noticed.