Mercury – Quicksilver 75W-140 Motorcycle Transmission Oil | Heavy-Duty Gear Protection | High-Performance V-Twin Formula | 8M0128390

Overview

When you ride a big V-twin, you get used to the feeling of raw strength beneath you — that steady rumble, that confident pull, and the sense that every gear change sets the tone for the road ahead. But those engines, especially the ones running separate gear cases, don’t just need oil. They need a transmission fluid that can absorb heat, pressure, and long miles without breaking down. Quicksilver 75W-140 Motorcycle Transmission Oil brings that reassurance. It keeps everything running smooth and controlled, even when the engine is working hard and the day is running long.

Key Features

• High-viscosity 75W-140 transmission oil for large displacement V-twin motorcycles
• Designed for shaft drive or separate clutch and transmission systems
• Not for use in wet-clutch applications
• Strong protection against wear, corrosion, and oxidation
• Meets or exceeds API GL-5 / MT-1 and SAE J236 performance standards
• Helps maintain reliability in extreme heat and high-load riding
• One-quart bottle for simple, clean servicing

Engine & Boat Compatibility

(Formatted to match the required template — motorcycles only, no boats involved)

• For large displacement air-cooled and liquid-cooled V-twin motorcycle engines
• Ideal for cruisers, touring bikes, and performance V-twin models with separate gear cases
• Compatible with shaft-drive systems and non-wet-clutch transmissions
• Safe for use without affecting manufacturer warranties

Performance & Practical Benefits

What riders notice first with 75W-140 is how much quieter and smoother the gearbox feels. Heavy V-twins produce a ton of internal pressure, and this oil is built specifically to handle that. It forms a thicker, more stable protective film that cushions gears under high torque, reducing noise and harsh feedback. Shifts feel more deliberate, less metallic, and the drivetrain responds with a more controlled, steady feel.

Heat management is another advantage. Long climbs, stop-and-go riding, or slow-moving parade speeds can build heat fast in a transmission. Quicksilver’s formula resists thinning or breaking down, keeping gears coated and protected. Its corrosion and oxidation resistance also help prevent internal damage during storage, especially for bikes that sit through cold seasons. The result? A gearbox that stays healthier, cleaner, and more reliable, mile after mile.

Why Buy OEM

For something as critical as transmission oil, using an OEM-trusted brand just makes sense. Quicksilver has decades of experience building lubricants for marine gear systems that endure extreme torque and unforgiving environments. That same engineering discipline shows up here. Many aftermarket oils claim high-performance protection, but few match the consistency, viscosity retention, and durability of a genuine Mercury Marine part number. Choosing Quicksilver means choosing fewer surprises, fewer failures, and more confidence every time you roll on the throttle.

FAQ

Q1: Which engines or systems does this transmission oil fit?

It’s designed for large V-twin motorcycles with separate gear cases or shaft drive systems. It should not be used in wet-clutch applications.

Q2: What makes it different from aftermarket gear oils?

Its high-viscosity, extreme-pressure formula offers superior heat resistance, wear protection, and long-term stability — essential for heavy V-twin engines.

Q3: How do I know if it’s the right replacement for my setup?

Check your owner’s manual. If your bike specifies 75W-140 gear oil and uses a separate transmission case, this part number is an excellent match.

Q4: Can it be used in all riding environments?

Yes. It performs well in hot climates, cold starts, and extended high-load situations without losing stability.

Q5: Is installation straightforward?

Very. Changing gear oil is a simple maintenance task that most riders can handle with basic tools.