Universal Lower Unit Gear Oil Pump | 3/8" 8mm 10mm Adapters

Keep your marine outboard and mechanical equipment running at peak performance with this Universal Lower Unit Gear Oil Pump. Engineered for efficiency and ease of use, this pump delivers stable, consistent lubrication to help extend the life of your gears and mechanical components.

Whether you're a boat owner topping off your outboard's lower unit, a maintenance technician in a workshop, or a marine mechanic on the dock, this pump makes the job clean, fast, and hassle-free. Made in Mainland China.

Key Features

• 3 Metal Adapters Included: Comes with 3/8-inch, 8mm, and 10mm adapters for broad compatibility with standard quart bottles and most marine outboard motors — including Mariner-style fittings.
• Durable Construction: Built from aluminum alloy and PC (polycarbonate) for a lightweight yet sturdy tool that stands up to workshop and marine environments.
• Efficient Flow Design: Optimized pump mechanism ensures a steady, controlled flow of gear oil — no spills, no mess.
• Wide Application: Ideal for outboard motors, lower unit gear cases, factory machinery, gearboxes, and mechanical equipment in workshops or industrial settings.
• No Battery Required: Manual operation — no power source needed, making it reliable anywhere you work.
• Versatile Compatibility: Fits standard quart-sized gear oil bottles commonly used for marine and industrial applications.

Specifications

• Material: Aluminum Alloy, PC (Polycarbonate)
• Adapters: 3/8 inch, 8mm, 10mm
• Battery Required: No
• Compatible With: Standard quart bottles, Mariner and most outboard lower units
• Country of Origin: Made in Mainland China

What's in the Box

• 1 × Lower Unit Gear Oil Pump Set (pump + 3 metal adapters)

Note: Please allow 1–3 cm measurement variance due to manual sizing. Actual color may vary slightly from product images due to monitor differences.

Great for Use With

Pair this pump with other marine and outdoor maintenance essentials from our store. Check out our workshop motivational wall art to keep your garage or boat shed inspired, or browse our full range of tools and accessories.

For more information on safe handling of lubricants and maintenance chemicals in marine and workshop environments, refer to guidance from the U.S. Environmental Protection Agency (EPA) — Oil Spill Prevention & Preparedness.

Frequently Asked Questions

Q: What size bottles does this lower unit gear oil pump fit?

A: This universal gear oil pump is designed to fit standard quart-sized gear oil bottles. It comes with three metal adapters — 3/8 inch, 8mm, and 10mm — to ensure compatibility with the most common bottle neck sizes used in marine and industrial applications.

Q: Is this pump compatible with Mariner and other outboard motors?

A: Yes! This pump is specifically designed to work with Mariner-style lower unit fill ports and is broadly compatible with most outboard motor brands. The included multi-size adapter set ensures you'll find the right fit for your lower unit drain/fill plug.

Q: Does this gear oil pump require batteries or any power source?

A: No — this is a fully manual pump. It requires no batteries or electricity, making it a reliable, portable tool for boat ramps, docks, workshops, or anywhere you need to service your lower unit gear oil.

Q: What is the pump made of?

A: The pump body is constructed from aluminum alloy and polycarbonate (PC), providing a durable yet lightweight build suitable for repeated use in marine and industrial maintenance environments.