Mercury – Driveshaft Housing Oil Seal | Sterndrive Seal | Marine-Grade Construction | 965031

Overview

There’s a certain trust you build with your sterndrive over the years—the kind that comes from smooth shifts, steady acceleration, and a hull that responds exactly when you need it to. But every seasoned boater knows that keeping a MerCruiser running strong isn’t about luck. It’s about maintaining the small things before they become big problems. The Mercury 965031 Driveshaft Housing Oil Seal is one of those quiet but critical parts that protects your drive from water intrusion and premature wear. When this seal is fresh, you feel it in the way your boat runs: tight, responsive, and ready for wherever the day takes you.

Key Features

• Designed specifically for MerCruiser R, MR, and Alpha sterndrives
• Provides a precise barrier against water intrusion and gear lube leaks
• Manufactured to Mercury OEM specifications for proper fit and long-term durability
• Easy to install using common shop tools
• Built from tough, marine-grade sealing materials engineered for heat, pressure, and constant water contact

Engine & Boat Compatibility

This oil seal is compatible with:

• MerCruiser R, MR, and Alpha One sterndrive models
• Boats powered by these drives, including:
  • Runabouts
  • Sport boats
  • Bowriders
  • Fishing boats
  • Ski and tow vessels

For the most accurate fit, always verify using your engine’s serial number and service documentation.

Performance & Practical Benefits

A driveshaft housing oil seal doesn’t just sit in place—it works nonstop to protect your sterndrive’s internal components. When the seal begins to fail, you’ll see the symptoms: milky gear lube, slipping performance, harsher shifts, and diminishing reliability. Replacing it with a genuine Mercury Marine part restores that tight, watertight barrier you depend on.

Once installed, you’ll notice:

• Smooth, steady shifting, especially under load
• Confident acceleration, free from the drag caused by contaminated gear lube
• Improved sterndrive longevity, preventing internal corrosion and bearing damage
• Reliable protection during heavy use, extended idle times, or long runs across choppy water

This small part makes a huge difference in how your boat feels and how long your drive lasts.

Why Buy OEM

When it comes to sealing components, precision is everything. Mercury OEM seals are engineered with exact tolerances, ensuring the right pressure and compression every time.

Here’s why experienced boaters stick with OEM:

• Exact-fit engineering eliminates guesswork
• Marine-grade materials last longer than many aftermarket alternatives
• Better protection for gear lube, shafts, and bearings
• Designed to perform right the first time, reducing the risk of repeat repairs
• Backed by decades of Mercury Marine engineering and real-world testing

A proper seal isn’t a place to cut corners—and OEM makes sure you don’t have to worry.

FAQ Section

Q1: Which Mercury systems does the 965031 oil seal fit?

It fits MerCruiser R, MR, and Alpha sterndrives.

Q2: What makes this seal better than aftermarket versions?

OEM seals use exact Mercury materials and tolerances, ensuring proper sealing pressure and better long-term reliability.

Q3: How do I confirm if this part fits my drive?

Check your owner’s manual or parts listing using your drive’s serial number.

Q4: Can it be used in both freshwater and saltwater?

Absolutely. It’s built to handle harsh marine environments of any type.

Q5: Is installation easy for most boat owners?

Yes—if you’re comfortable servicing sterndrives, this seal installs easily with standard tools.