Lower Unit Oil Seal for Mercury 6/8/9.9/10/15HP 18-0584 18-0586 18-0585 25-33145

Lower Unit Oil Seal for Mercury

This lower unit oil seal for Mercury outboard engines replaces original part numbers 18-0584, 18-0586, 18-0585, and 25-33145 to stop gearcase leaks.

Overview

The lower unit oil seal for Mercury outboards is engineered for 6, 8, 9.9, 10, and 15 horsepower models. It works to keep gearcase oil in and water out, preserving the lower unit's performance. This seal set is a direct cross-reference to the listed Mercury part numbers.

Built For Performance

• Precision-molded seals for a tight, leak-free fit
• Resistant to oil, seawater, and temperature extremes
• Includes all necessary seals for the 6-15HP range
• Meets or exceeds original equipment specifications
• Easy to install with basic hand tools

Fits These Machines

• for Mercury 6HP outboard
• for Mercury 8HP outboard
• for Mercury 9.9HP outboard
• for Mercury 10HP outboard
• for Mercury 15HP outboard

On-The-Job Use

• Replaces failing seals during lower unit service
• Prevents oil leaks that attract grime and cause overheating
• Keeps water out of the gearcase to protect bearings
• Suitable for both saltwater and freshwater use

Specs At A Glance

Good To Know

Q: Will this seal set work on my 2001 Mercury 8HP? A: It is designed for 6-15HP Mercury models, but always confirm your engine's serial number before ordering.

Q: What is the difference between these seals and OEM? A: These are aftermarket seals made to match OEM specs, providing a reliable replacement at a lower cost.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.