Mercury Outboard Lower Unit Oil Seal kit 6/8/9.9/10/15HP 18-0584 18-0585 18-0586

Lower Unit Oil Seal kit for Mercury

This lower unit oil seal kit for Mercury outboard engines includes seals 18-0584, 18-0585, and 18-0586 to replace worn seals in the gearcase.

Overview

The lower unit oil seal kit for Mercury outboards is designed for 6, 8, 9.9, 10, and 15 horsepower models. This kit provides the essential oil seals to prevent gearcase leaks and keep water out of the lower unit. It is a direct replacement for the original Mercury parts.

Built For Performance

• Includes three precision seals (18-0584, 18-0585, 18-0586)
• Made from nitrile rubber for oil and water resistance
• OEM-spec dimensions for a snug fit
• Resists cracking and hardening over time
• Simple installation with standard 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

• Use during lower unit rebuilds to stop gear oil leaks
• Replace worn seals when changing impeller or gearcase oil
• Prevents water intrusion that can damage gears and bearings
• Ideal for marine mechanics and DIY boat owners

Specs At A Glance

Good To Know

Q: Will these seals fit my 1999 Mercury 9.9? A: The kit is designed for 6-15HP Mercury outboards, but verify the serial number of your engine for exact compatibility.

Q: Are these seals OEM? A: These are aftermarket seals made to OEM specifications, not original Mercury parts.

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