Best Marine Lower Unit Gear Oil

Peter | 26-12-2025

If you aren’t someone who makes frequent purchases, selecting the best Best Marine Lower Unit Gear Oil won’t be an easy chore for you. However, you shouldn’t be concerned because we have provided you with the most comprehensive list possible of the top Best Marine Lower Unit Gear Oil. Have a look at the products on our list, and pick the ones that appeal to you the most.

We researched and tested Best Marine Lower Unit Gear Oil in the market to get you this list. Our most recommended product is Quicksilver Best Marine Lower Unit Gear Oil. Check out our picks for all of our favorites, and be sure to read our buying guide to get all the information you need to make the best choice!

Editor's Choice
Quicksilver SAE 90 High Performance Gear Lube for Outboards and Sterndrives, 32 oz
Quicksilver SAE 90 High Performance Gear Lube for Outboards and Sterndrives, 32 oz
Premium Pick
Valvoline FlexFill Advanced Full Synthetic Full Synthetic 75W-90 Gear Oil 1 QT FlexFill
Valvoline FlexFill Advanced Full Synthetic Full Synthetic 75W-90 Gear Oil 1 QT FlexFill
Budget Pick
Quicksilver SAE 90 High Performance Gear Lube and Pump Kit for Mercury Outboards and Mercruiser
Quicksilver SAE 90 High Performance Gear Lube and Pump Kit for Mercury Outboards and Mercruiser

Top 10 Best Marine Lower Unit Gear Oil

We researched and compared the top products in the Best Marine Lower Unit Gear Oil category to provide you with these recommendations.

1. Quicksilver SAE 90 High Performance Gear Lube for Outboards and Sterndrives, 32 oz

Quicksilver SAE 90 High Performance Gear Lube for Outboards and Sterndrives, 32 oz
9.8

Quicksilver

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  • Lower unit gear oil formulated to protect against corrosion and excessive wear
  • Designed for outboard motor lower unit and sterndrive applications above 75hp
  • Extreme pressure synthetic additives protect gears from metal to metal contact
  • SAE 90 viscosity
  • Manufacturer part number 8M0222065

2. Quicksilver by Mercury Marine 80W-90 Premium Gear Lube, Marine Engine, 32 oz.

Quicksilver by Mercury Marine 80W-90 Premium Gear Lube, Marine Engine, 32 oz.
9.1

Quicksilver

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  • Direct replacement for Mercury Marine 858058K01
  • Provides maximum protection against excessive wear, corrosion and pitting for extended gear life in marine applications
  • Contains additives to protect gears if water enters the gear case or lower unit
  • Recommended for use in outboard motor gear cases and marine lower units in applications below 75hp
  • 80W-90 viscosity
  • 32 oz. bottle (pack of 6)
  • Produced to meet Mercury Marine original equipment manufacturer specifications to best protect your engine

3. Lucas Oil 10652 Synthetic SAW 75W-90 M8 Marine Gear Oil - 1 Quart

Lucas Oil 10652 Synthetic SAW 75W-90 M8 Marine Gear Oil - 1 Quart
9.1

Lucas Oil

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  • For best performance, follow the manufacturer's recommendations in your vehicle owners manual.

4. Bolaxin Lower Unit Gear Oil Pump for Standard Quart Bottles, 3/8 inch Metal Swivel, 8mm and 10mm

Bolaxin Lower Unit Gear Oil Pump for Standard Quart Bottles, 3/8 inch Metal Swivel, 8mm and 10mm
7.9

Bolaxin

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  • Lower Unit Gear Oil Pump fits for Standard Quart Bottles. Fits for Most Marine Boat Outboard Motors (NOT fits for VOLVO PENTA).
  • Fits for all standard 1 quart lower unit lube bottles. Perfect for most 32 ounce outboard gear oil bottles.
  • Pump 8CC per pump stroke. Easily press down. Comes with 2 Rigid Suction Tubes to ensure the pump can reach the battom of tall and short bottles.
  • 3 Adapters Sizes: 3/8" swivel adapter connected to clear plastic tubing. 8mm and 10mm metal adapter fits for most foriegn outboard motor's lower unit drain threads hole.
  • Buy according to your needs, with different adapters, this lower unit gear oil pump change and refills the marine motor lower unit gear lube in a few minutes. Easily and quickly work.
  • Packaged: 3*adapters, 2*tubes, 1*pump, 1*hose. Having any questions, please contact to us and got an ideal solution.

5. Mercury Marine New OEM High Performance Gear Lube with Hand Pump, 91-8M0101435

Mercury Marine New OEM High Performance Gear Lube with Hand Pump, 91-8M0101435
8.9

Mercury

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  • Genuine OEM Factory Original Equipment Mercruiser Sterndrive & Outdrive Oil
  • Exclusive formula is engineered to provide extended gear life in extreme conditions including high-speed and high-horsepower applications
  • Extreme pressure synthetic additives protect gears from metal to metal contact
  • Engineered to provide maximum protection for sterndrive and outboard lower units
  • For use in most gear housings of Mercruiser sterndrives and all Mercury, Mariner, and Force Outboards

6. Quicksilver SAE 90 High Performance Gear Lube and Pump Kit for Mercury Outboards and Mercruiser

Quicksilver SAE 90 High Performance Gear Lube and Pump Kit for Mercury Outboards and Mercruiser
9.5

Quicksilver

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  • Lower unit gear oil formulated to protect against corrosion and excessive wear
  • Designed for outboard motor lower unit and sterndrive applications above 75hp
  • Extreme pressure synthetic additives protect gears from metal to metal contact
  • SAE 90 viscosity
  • Produced to meet Mercury Marine original equipment manufacturer specifications to best protect your engine
  • Previous manufacturer part number 802891Q05
  • Manufacturer part number 8M0222069

7. Yamaha Original OEM Yamalube Acc-GEARL-UB-GL Marine Lower Unit Gearcase Lube Yamalube OEM - 1 Gallon

Yamaha Original OEM Yamalube Acc-GEARL-UB-GL Marine Lower Unit Gearcase Lube Yamalube OEM - 1 Gallon
8.3

Yamaha Motor

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  • Original Yamalube Yamaha OEM Marine Lower Unit Gearcase Lube ACC-GEARL-UB-GL
  • Includes: (1) Gallon
  • Superior marine lubricant designed to protect gearcase components operating at high speeds for extended periods in fresh or saltwater applications, includes robust rust and corrosion inhibitors for long life.
  • This Yamalube Marine Gear Case Lube is intended for use in all outboards of 250 HP or less (excluding Yamaha 4.2L V6 outboards).
  • Made by Yamaha specifically for Yamaha

8. Yamaha New OEM 32 OZ. Lower Unit Gearcase Lube Quart, ACC-GEARL-UB-QT

Yamaha New OEM 32 OZ. Lower Unit Gearcase Lube Quart, ACC-GEARL-UB-QT
8

Yamaha Motor

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  • Flash Point: 161 Degrees Celsius
  • Liquid Volume: 32 Fluid Ounces
  • 80W-90 Weight
  • High viscosity formula protects drives from high speed and high load use
  • Formula includes unique rust and corrosion inhibitors to protect internal engine components even in saltwater environments

9. Valvoline FlexFill Advanced Full Synthetic Full Synthetic 75W-90 Gear Oil 1 QT FlexFill

Valvoline FlexFill Advanced Full Synthetic Full Synthetic 75W-90 Gear Oil 1 QT FlexFill
9.8

Valvoline

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  • FlexFill squeezable pouch releases 2X more fluid with less effort for 3X faster filling vs. traditional bottle packaging
  • Contains limited slip for optimal performance of the clutch pack, while also delivering 30% better protection against towing and heavy loads and 1.5X better gear wear protection
  • Advanced full synthetic helps prevent noise and reduce chattering, while protecting gear teeth from wearing out prematurely
  • High and low temperature protection ranges from -50F to 300F degrees for cold temperature fluidity and high temperature performance
  • Fights rust and corrosion with corrosion inhibitors and safeguards against impurities, oxidation and thermal breakdown
  • Meets or exceeds requirements for: SAE J2380, MACK GO-J, Meritor 0-94 Rev Level A, API GL-5, GMW 16445; the addition of a supplemental friction modifier (Ford M2C-118-A, Chrysler MS-5630, or GM 1052358) is not required. Can be used in non-synchronized manual transmissions calling for API GL-4
  • American made and formulated, from the Original Motor Oil brand trusted for more than 150 years

10. TRIAX Marine Gear SAE 90 Full Synthetic Oil | for All Stern Drives, Bow Thrusters, and Lower Gear

  • FULLY CORROSION INHIBITED: For both salt and freshwater use; prevents rust and corrosion on transmission components; protects brass, copper, and aluminum alloys
  • WIDELY COMPATIBLE: Compatible with all lower gear units / sterndrives on all JetSkis, Jet Pumps, and Sports Jets made by Mercury / Mariner, Johnson / Evinrude, Bombardier, Honda, Yamaha, Suzuki, Force / US Marine, Nissan, Tohatsuand Harbormaster; Sterndrives made by Mercruiser-Bravo, OMC / Bombardier, Volvo-Penta, Yanmar, Konrad, and Marine Drive Systems; V-drives made by Casale & Menkins; bow thrusters made by Harbormaster Marine; and transmissions made by ZF Marine Transmission
  • EXTREME OXIDATION STABILITY: Full synthetic formulation (unlike OEM fluids) provides exceptional thermal stability and oxidation inhibition even in high thermal and mechanical loads; IDEAL FOR STORAGE: long term stability protects
  • FULL SEAL PROTECTION: Contains specialized additives to maintain seal pliability helping to maintain water tightness of gear units preventing water intake
  • EXCELLENT FRICTIONAL PROPERTIES: Prevents gear slippage, sticking even with sudden high torque acceleration, towing or accidental over-revving (when the prop is outside of the water)

Peter

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