Mercury – Complete Gearcase | Bravo Three / Three X / Three XR Series | Corrosion-Resistant Alloy | 8M0046738

Overview

Anyone who’s run a Bravo Three drive long enough knows the lower unit carries the weight of every good day on the water. When it’s strong, smooth, and dependable, you feel it instantly—your boat lifts with purpose, tracks clean through chop, and settles into a rhythm that just feels right. That kind of confidence is priceless, especially when you’re miles from the ramp with a full crew and the weather starts shifting. The Mercury 8M0046738 Complete Gearcase is built for boaters who rely on their equipment not just for performance, but for peace of mind. It restores that steady, predictable feel you remember from the boat’s best days.

Key Features

• Complete OEM gearcase for Bravo Three, Three X, and Three XR sterndrives
• Designed for 1.81, 2.00, and 2.20 gear ratio applications
• Corrosion-fighting XK360 alloy for long-term durability
• Tri-Paint protective coating resists harsh marine environments
• Heavy-duty near-net forged gears for smoother, stronger engagement
• Factory-spec construction for precise fit and optimal performance

Engine & Boat Compatibility

Fits:

• Bravo Three and Bravo Three X sterndrives with 1.81, 2.00, or 2.20 gear ratios
• Bravo Three XR sterndrives with 2.00 gear ratio

Common boat types:

• Offshore fishing boats
• Sport cruisers
• Tow and surf boats
• Multi-engine offshore setups
• Heavier cabin boats and performance hulls

Performance & Practical Benefits

When you bolt on the 8M0046738 gearcase, the difference is more than mechanical—it’s something you feel every moment you’re behind the helm. Shifts become crisp without being harsh. Throttle response stays smooth and predictable. The forged gears mesh cleanly, giving you that solid, no-nonsense engagement Mercury drives are known for.

If you run bigger props or twin-counter-rotating sets, you’ll appreciate how steady the drive feels even under heavy load. Whether you’re easing into a tricky marina slip or trimming up to run across open water, everything feels tighter and more controlled. That’s the beauty of an OEM gearcase restored to proper spec.

Saltwater boaters will especially value the corrosion resistance. Mercury’s XK360 alloy and Tri-Paint coating work together to slow down the kind of wear that usually shows up after a few seasons in the elements. It’s built to handle long-term exposure, regular haul-outs, and the abuse that real-world boating dishes out.

Installation is straightforward thanks to the precise machining and exact Mercury geometry. You’re not fighting misaligned surfaces or questionable tolerances. It fits right, seals right, and performs the way the rest of your Bravo system was engineered to.

Why Buy OEM

A gearcase is not a part where “close enough” is ever good enough. Mercury OEM components are engineered specifically for the torque, thrust, and shifting loads of Bravo drives. Aftermarket units often cut corners on metallurgy, tolerances, or coatings—and those shortcuts show up in the form of premature wear, noisy shifting, or corrosion.

Choosing OEM means:

• Proper fit the first time
• Longer lifespan
• Reduced maintenance headaches
• Performance that matches factory expectations
• Protection for the rest of your drivetrain

It’s the seasoned boater’s choice because it simply works—and keeps working.

FAQ

Q1: Which sterndrives does this gearcase fit?

Bravo Three, Bravo Three X, and Bravo Three XR models within the supported gear ratios.

Q2: What makes OEM better than aftermarket?

Higher-grade metals, exact tolerances, factory engineering, and proven reliability.

Q3: How do I confirm it’s the right ratio?

Match your current gear ratio and sterndrive serial number with Mercury’s specifications.

Q4: Can it handle both freshwater and saltwater?

Yes—its alloy and coating are built specifically for long-term corrosion resistance.

Q5: Is installation straightforward?

Most marine technicians install it easily, and experienced boaters can do it with the correct tools.