MERCURY SAE 90 Marine Gear Lube 1 Quart — High Film Strength & Corrosion Protection

MERCURY SAE 90 High Performance Gear Lube (1 qt) is a marine-grade gear oil designed to protect outboards, sterndrives and jet pumps from wear, pitting and corrosion—even when water is present.

This specially formulated SAE 90 gear lube meets Mercury Marine original equipment specifications and is engineered for engines 75hp and larger. It delivers durable film strength and corrosion resistance to internal gearcase components, helping maintain smooth shifting and long service life in harsh saltwater and freshwater environments. Use with the Mercury gear lube pump (part 8M0072135) for a clean, controlled fill.

How does this oil prevent damage when water gets into the gearcase?

The formulation contains additives that maintain lubricity and resist breakdown even if small amounts of water are present in the gearcase. That prevents metal-to-metal contact and reduces pitting and surface fatigue over time. It’s not a water-removal product, but it protects components between service intervals.

• High film strength to prevent metal wear
• Anti-corrosion additives guard internal surfaces
• Stable viscosity under marine temperature ranges

Which engines and drive types are compatible with this gear lube?

Designed for use in outboard lower units, sterndrives and jet pumps on engines of 75 horsepower and above. It’s suitable for Mercury, Mariner and MerCruiser systems and other marine drives calling for SAE 90 gear oil. Always check your engine manual to confirm recommended lubricant specifications.

• Outboards and lower units (75hp+)
• Sterndrives and sport jet drives
• Meets Mercury Marine OEM requirements

How should I fill or change gear lube to keep my drive reliable?

Drain and inspect the old lubricant for contaminants or water, then refill with clean Mercury SAE 90 using the recommended pump for a neat, complete fill. Replace seals or fasteners if they show damage, and torque drain and fill plugs to factory specs. Regular checks during service seasons catch problems early.

• Use gear lube pump 8M0072135 for clean filling
• Inspect drained oil for milky appearance or metal particles
• Follow manufacturer torque and fill volume guidance

What performance benefits can I expect from using genuine Mercury gear lube?

Using Mercury’s SAE 90 formulation helps preserve gearcase components, promotes consistent gear engagement and reduces the risk of premature failure. Because it’s produced to OEM standards, compatibility and warranty considerations remain straightforward. The one-quart size is convenient for single-service needs or topping off reservoirs.

• Extends gear component life with protective additives
• Reduces risk of pitting and wear under load
• OEM-grade consistency for reliable performance

Who this is for: Boaters, marine technicians and service shops who maintain outboards, sterndrives or jet drives rated 75hp and above and want an OEM-specified, high-viscosity gear lube that stands up to marine conditions. Ideal for seasonal maintenance, pre-launch service checks and professional repairs where dependable protection and clean filling are required.

• Product: MERCURY SAE 90 High Performance Gear Lube
• Part number: 8M0222063
• Size: 1 Quart