Marine Gear Oils
AMSOIL synthetic marine gear oil is engineered to provide outstanding protection for marine lower units and gearcases operating under high loads and demanding on-water conditions. Its advanced synthetic formulation helps protect gears and bearings against wear while maintaining dependable lubrication throughout the boating season.
Designed specifically for marine driveline applications, AMSOIL marine gear oil provides high-performance protection for compatible outboard and sterndrive lower units and other marine gearcases.
AMSOIL Synthetic Marine Gear Oil
Marine gearcases operate under demanding conditions, transmitting substantial engine power while exposed to sustained loads, high operating speeds and the possibility of water contamination. The correct gear lubricant helps protect gears, bearings and other critical components against wear while maintaining dependable lubrication throughout marine service.
AMSOIL synthetic marine gear oil is formulated specifically for marine drivetrain applications, providing strong protection for compatible outboard lower units, stern drives and other marine gearcases.
Why Marine Gearcases Need the Right Lubricant
Outboard lower units and stern drives contain heavily loaded gears operating within compact housings. Gear teeth are subjected to considerable pressure as engine power is transferred to the propeller, requiring a lubricant capable of maintaining a protective film between loaded surfaces.
Marine operation also presents a challenge not normally encountered to the same degree in automotive differentials: exposure to water. Damaged seals, fishing line around a propeller shaft or other sealing problems can allow water into the gearcase, compromising lubrication and increasing the risk of corrosion and component damage.
Marine Gear Oil vs Automotive Gear Oil
Automotive and marine gear oils may carry similar SAE viscosity grades or gear-lubricant classifications, but this does not automatically make them interchangeable. Marine gear lubricants are formulated around the operating environment and requirements of marine drivetrain components.
Select gear oil according to the requirements specified by the engine or drive manufacturer rather than choosing an automotive differential oil simply because its viscosity appears similar.
Check Your Gear Oil During Servicing
Changing marine gear oil also provides an opportunity to inspect the drained lubricant. Oil with a milky or emulsified appearance can indicate water contamination, while unusual metallic debris may indicate internal wear. Evidence of contamination should be investigated rather than simply refilling the gearcase with fresh oil.
Find the Correct Marine Lubricants
Always check the lubricant specification and viscosity required for your particular outboard, stern drive or marine gearcase. Use the AMSOIL Product Finder where application information is available to identify suitable engine oils, gear lubricants and other AMSOIL products for your marine equipment.
