SankWin Boat Lower Unit Gear Lube Pump — Manual Outboard/Outdrive Transfer Kit with Multi‑Adapters

The SankWin boat lower unit gear lube oil pump is a manual transfer kit that lets you extract and refill lower unit gear oil, transmission fluid, and differential fluid from most outboard and stern-drive marine engines.

If you service your own boat or need a reliable pump for occasional maintenance, this compact kit gives you a leak-minimizing way to move viscous gear fluids between standard quart bottles and marine gear housings. Built to work with many Mercury, Yamaha, Honda, Suzuki, Evinrude, MerCruiser and OMC models, the pump includes multiple adapters and flexible tubing so you can reach awkward drain ports without spilling oil over the engine or deck.

Which engines and drives will this pump work with?

The SankWin kit is designed for broad compatibility across popular U.S. and international outboards and stern drives. The included 3/8" swivel steel adapter fits most MerCruiser/OMC stern drives and many Johnson, Evinrude, Mercury, Mariner and Force lower units. Additional 8mm and 10mm adapters extend fitment to many Yamaha, Honda, Suzuki and Tohatsu models.

• 3/8" swivel steel adapter for MerCruiser and many Mercury/Johnson/Evinrude outboards
• 8mm and 10mm adapters for Yamaha, Honda, Suzuki and other international outboards
• Works with standard quart bottles with 28mm openings

How easy is it to use during a DIY gear oil change?

The manual pump is straightforward: attach the rigid suction tube or flexible hose to the pump, select the correct adapter, and hand-pump gear lube in or out. Its compact construction helps you avoid tipping bottles and keeps fluid transfer tidy, making routine lower unit service faster and less messy.

• Hand-operated pump requires no power source or special tools
• 50cm flexible hose reaches recessed drain ports and awkward angles
• Rigid suction tubes provide firm insertion for suction and refill operations

What parts are included and what do they do?

The kit bundles the pump itself plus adapters, tubes and mounting bits so you can adapt to a wide range of service scenarios. A small clamp and drain screw gaskets are included so you can create a secure seal at common lower unit access points, reducing the chance of leaks while pumping.

• Manual oil pump body for controlled pumping action
• 50cm flexible hose and rigid suction tubes for reach and stability
• 3/8" swivel steel adapter, 8mm and 10mm adapters for multi-brand fit
• Clamp and drain screw gaskets for reliable sealing during transfer

Will this pump handle different fluid types and viscosities?

This pump is intended for gear oil, transmission fluid and differential fluids commonly used in marine lower units. Its design accommodates viscous fluids encountered in marine service, providing consistent flow when hand-operated. However, always confirm compatibility with your specific lubricant and observe proper disposal rules for used oil.

• Compatible with gear lube, trans fluid and differential fluids
• Manual operation delivers controlled flow for thicker oils
• Works with standard quart bottles to simplify refills

Who is this for: Boat owners, independent mechanics and marina technicians who perform routine lower unit servicing will benefit from the SankWin gear lube oil pump. It suits DIYers looking to minimize spills and save on service bills, as well as professionals who need a portable, adaptable pump for multiple engine brands and model years. Keep replacement gaskets and proper disposal plans on hand, and verify adapter fitment for your exact lower unit before beginning work.