SE106, UPPER 1.47 (Replaces Mercruiser Alpha One)
Introduction
The SE106, UPPER 1.47 (Replaces Mercruiser Alpha One) is one of the most trusted replacements in the boating industry for Alpha One Gen I sterndrives. Designed specifically for marine environments, this upper gear housing delivers exceptional reliability and optimal performance. Whether you are restoring your boat’s propulsion system or upgrading to better fuel efficiency, the SE106 Upper 1.47 is a high-quality, cost-effective solution tailored for boating professionals and enthusiasts alike.
This component is engineered to meet or exceed OEM specifications, making it a perfect replacement for Mercruiser Alpha One Gen I Upper Only units. With its precision-machined internals, gear ratio of 1.47:1, and seamless compatibility, you can expect smooth power transmission and long-term durability even in harsh saltwater conditions.
From easy installation to robust corrosion resistance, the SE106 Upper 1.47 is made for boaters who demand excellence. Whether you’re cruising, fishing, or towing, this sterndrive upper gear unit gives your vessel the dependable thrust and control you need.
Overview / What Is SE106, UPPER 1.47?
The SE106 Upper 1.47 is a high-performance upper gearcase assembly designed as a direct replacement for the Mercruiser Alpha One Gen I upper housing. With a 1.47:1 gear ratio, it is perfectly suited for V6 and small-block V8 marine engines operating in various recreational and light commercial marine environments.
This upper unit houses the vertical drive shaft and gears that transmit power from your engine to the lower gearcase and propeller. The 1.47 gear ratio is ideal for boats that require a balance between speed and torque, making it a common setup for many stern-driven vessels.
Key Features of SE106 Upper 1.47
- Direct Replacement: Fully compatible with Alpha One Gen I (1972–1990 models).
- Gear Ratio: 1.47:1, suited for V6 and 305-350 V8 engines.
- Quality Construction: Made with heavy-duty marine-grade alloys and stainless steel hardware.
- Corrosion Resistant: Coated to withstand both fresh and saltwater environments.
- Pre-filled Gear Oil: Some units come pre-lubricated for quick installation.
Installation Guide: How to Install SE106 Upper 1.47
Installing the SE106 Upper 1.47 requires standard marine tools and a basic understanding of sterndrive assembly. Here’s a simplified step-by-step:
- Remove the old upper unit, disconnecting the drive shaft and water lines.
- Clean all gasket surfaces thoroughly and inspect the lower gearcase and coupler.
- Mount the SE106 Upper to the existing lower unit, aligning the vertical shaft.
- Secure with stainless bolts and torque to factory specs.
- Check alignment, refill gear oil if needed, and perform a test run on land (with water hose).
Professional installation is recommended for first-timers to ensure optimal performance and warranty retention.
Why Choose SE106 Over OEM Mercruiser?
While OEM parts are trusted, the SE106 Upper 1.47 provides cost savings without compromising performance. Built by SEI Marine Products, this aftermarket part matches or exceeds Mercruiser’s durability and precision. It’s also backed by warranties and excellent technical support from suppliers like All Boat Supplies.
In many cases, boaters report smoother engagement, quieter operation, and less prop slippage after installing the SE106 unit. The aftermarket model also tends to come with updated materials and improvements that were not available in original Alpha One units from the 80s and 90s.
Maintenance Tips
To extend the life of your SE106 Upper 1.47, routine maintenance is essential. Here are key tips:
- Check Oil Levels: Use high-quality marine-grade gear oil and inspect every 50 hours of operation.
- Inspect for Leaks: Look for oil drips or water intrusion after each outing.
- Flush Saltwater: Always flush the drive with fresh water after saltwater use.
- Grease Fittings: Apply marine grease to zerk fittings and shift linkage areas monthly.
- Store Correctly: Tilt the drive down during storage to avoid water ingress and bearing wear.
By maintaining your sterndrive properly, you ensure top performance, reduce repair costs, and enjoy smoother boating experiences.
Expert Advice and Pro Recommendations
When choosing a replacement upper unit for your Alpha One, make sure the gear ratio matches your engine output and boat weight. The SE106 Upper 1.47 is optimized for V6 and most V8 marine applications, making it a versatile and reliable choice.
Seasoned marine mechanics often recommend replacing both the upper and lower gearcase if you’ve experienced catastrophic failure or water intrusion. However, for targeted upper-unit replacement, the SE106 is the top-rated aftermarket solution.
Buy now: SE106, UPPER 1.47 (Replaces Mercruiser Alpha One) and enjoy 5% off with code WELCOME5.
Cost and Durability of SE106 Upper Units
The SE106 Upper 1.47 is often priced 30–40% less than OEM units. It offers high durability with a marine-hardened finish and improved gear metallurgy. Compared to aging Alpha One OEM units, SE106 gearcases have been reported to last longer due to tighter manufacturing tolerances and newer technology.
Cost-efficiency also comes from its compatibility with standard Alpha One lower units, saving you money on full replacement kits or custom machining. It is a long-term investment for boaters looking for reliable propulsion at a fair price.
Detailed FAQ Section
What engines are compatible with SE106 Upper 1.47?
The SE106 Upper 1.47 is designed to be compatible with Mercruiser Alpha One Gen I sterndrives from model years 1972–1990. The 1.47:1 gear ratio makes it ideal for engines including GM 4.3L V6, 5.0L V8, and 5.7L 350 CID small block configurations. It’s crucial that your lower unit and gimbal housing match the Alpha One Gen I specs to ensure a perfect fit.
If you’re unsure, check the serial number on your existing unit or consult with a marine technician to confirm compatibility. All Boat Supplies also offers real-time support via chat to help identify the right replacement.
How long does SE106 Upper 1.47 last?
With proper maintenance, the SE106 Upper 1.47 can last anywhere from 5 to 10 years depending on usage and water conditions. Built from high-strength marine alloys and featuring precision-machined gears, it resists corrosion and wear effectively in both fresh and saltwater. Some boaters have reported over 1,000 hours of smooth operation when the drive is flushed regularly and gear oil is changed as recommended.
Remember, longevity also depends on propeller size, proper installation, and load conditions. Using the wrong gear ratio or overloading the drive can shorten its lifespan significantly.
What’s the warranty coverage for SE106 Upper?
SEI typically offers a 3-year fault-free warranty for the SE106 Upper 1.47. This covers defects in materials and workmanship under normal use. If you purchase through authorized dealers like All Boat Supplies, you also get expert installation advice and support on warranty claims.
Always retain your invoice and register your product if required to activate the warranty. Unauthorized modification or incorrect installation may void coverage, so professional installation is advised.
Can I install SE106 Upper myself?
Yes, if you have experience working on marine engines or drives, you can install the SE106 Upper 1.47 yourself. The unit is built to bolt directly onto compatible Alpha One Gen I lower units. Installation typically requires marine-grade tools, alignment bar, gasket sealer, and a torque wrench.
However, for first-time users, having a certified marine mechanic assist can prevent misalignment and damage. Misalignment is the most common cause of premature gear failure and vibration issues in sterndrives.
Is SE106 Upper 1.47 good for saltwater use?
Absolutely. The SE106 Upper 1.47 is designed with corrosion-resistant coatings and marine-specific materials that withstand saltwater environments. Stainless steel hardware, zinc anodes, and sealed gear oil compartments help protect the internals from rust and degradation.
That said, flushing the drive with fresh water after each saltwater outing and applying anti-corrosion spray will further extend the lifespan of your SE106 unit. Also consider bottom painting or drive coatings for added protection.
Conclusion
The SE106 Upper 1.47 is a smart and powerful replacement for the Mercruiser Alpha One Gen I upper unit. With a robust design, seamless compatibility, and excellent durability, it’s a go-to choice for thousands of marine engine owners across the globe. Whether you’re repairing an aging drive or upgrading your current setup, this unit offers premium performance without the premium price tag.
Choose the SE106 for reliable thrust, better fuel economy, and long-term marine performance.
Special Offer
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