Mercury – Premium Gear Lube 80W-90 | Outboards & Sterndrives | Marine Formula | 858007K01

Overview

There is a quiet confidence that comes when you know your gear is ready for anything the water throws your way. That’s what Mercury’s Premium Gear Lube 80W-90 delivers — steady, reliable protection that doesn’t quit, even when the weather turns and the waves start to talk back. Whether you’re cruising along the shoreline or running wide open across open water, you’ll feel the difference in every smooth shift and quiet hum from the lower unit. It’s the kind of assurance that only comes from a product built by people who live and breathe the water.

Key Features

• Specially formulated marine gear lube designed to protect against wear and corrosion.
• Engineered for outboards up to 75 horsepower and compatible sterndrive systems.
• Premium 80W-90 viscosity for reliable lubrication under heavy loads.
• Improved emulsifiers safeguard gears even if water enters the gear housing.
• Available in a 5-gallon container for convenient refills and maintenance routines.
• Produced to Mercury Marine OEM standards for performance and longevity.

Engine & Boat Compatibility

• Ideal for Mercury outboards up to 75 HP
• Suitable for Mercury and Mariner sterndrives requiring 80W-90 gear lube
• Commonly used in fishing boats, pontoon boats, and small cruisers
• Trusted by recreational and professional boaters alike

Performance & Practical Benefits

Out on the water, you don’t have time to second-guess what’s happening below the surface. This Mercury Marine part keeps your gearcase running smooth and steady, so every throttle push feels tight and every turn stays true. The formula clings to metal surfaces, creating a strong barrier that fights friction, rust, and corrosion — especially in the harsh marine environments that chew up lesser lubes.

What sets this gear lube apart is its balance: thick enough to handle torque, but clean and slick for effortless shifting. Even if water finds its way inside the lower unit, the advanced emulsifiers keep things stable until you can service it properly. It’s one of those unseen parts of boating that quietly does its job, giving you the peace of mind to focus on what really matters — the run, the sound of the motor, and the freedom of open water.

Why Buy OEM

There’s a reason seasoned boaters stick with genuine Mercury parts. They’re built by the same engineers who designed your engine, tested in real-world conditions, and proven to last. With OEM gear lube, you’re not gambling with unknown formulas or fitment issues — you’re getting consistent, dependable performance every time. It’s a simple equation: fewer headaches, longer service life, and better protection for your investment. Over time, that reliability pays for itself.

FAQ Section

Q1: Which Mercury engines or systems does the Premium Gear Lube 80W-90 fit?

It’s formulated for Mercury and Mariner outboards under 75 horsepower, as well as compatible sterndrive gearcases.

Q2: What makes this part different from aftermarket alternatives?

Mercury’s OEM gear lube is engineered for marine use from the start — with additives that resist water intrusion and protect gears under high load and heat.

Q3: How do I know if this is the correct replacement for my setup?

Check your owner’s manual for Mercury’s 80W-90 gear lube recommendation, or verify your part number (858007K01) with your dealer.

Q4: Can this be used in both saltwater and freshwater applications?

Absolutely. It’s designed to handle both environments and protect against corrosion in either condition.

Q5: Is installation straightforward for most boat owners?

Yes, applying gear lube is a simple maintenance task for most do-it-yourself boaters — just follow Mercury’s instructions and proper fill levels.