Your Complete Guide to Replacement Gearcases
Why This Course Matters
Replacing a damaged gearcase is one of the most frequent and expensive repairs boaters face. The lower unit is particularly susceptible to damage from hidden underwater objects, making it a common repair necessity.
With numerous options available, doing your research before making a purchase is crucial. Avoid the temptation to choose the first unit you find—knowledge is key! By understanding your product and buying from a reputable company, you can ensure a reliable replacement that suits your engine perfectly.
What You’ll Learn
Throughout this course, we’ll discuss the different replacement options, provide tips, and equip you with the information you need to make the best choice for your boat.
Understanding Gearcase Terminology
Before diving into the replacement options, let’s get familiar with some essential terminology and components. Knowing these basics will help you communicate effectively with mechanics, insurance agents, and fellow boaters.
Key terms and Definitions
- Gearcase or Lower Unit: Also called gear housing, driveshaft housing, foot, or lower housing.
- Upper Unit: Found in sterndrive engines, it contains the driveshaft that connects through the transom to your engine.
- Outdrive or Drive Unit: Refers to the combination of the upper and lower units in sterndrive systems.
- Gears/Gearbox: The section of the lower unit where gears are located.
- Propshaft or Driveshaft: Transmits torque and rotation, connecting components of the drivetrain.
- Splines: Ridges on a driveshaft that mesh with grooves in a mating piece to transfer torque.
- Clutch: Engages and disengages power transmission between shafts.
- Skeg: The lowest point of an outboard or sterndrive motor, offering protection and stability.
- OEM (Original Equipment Manufacturer): Parts made by the original manufacturer of your boat engine, ensuring exact specifications and quality. Examples include Mercury, OMC, and Volvo-Penta.
- Non-OEM: Aftermarket parts made by companies other than the original manufacturer.
What’s Next?
With the terminology down, you’re ready to dive deeper into the world of replacement gearcases. In our next article, we’ll explore New Non-OEM Gearcases, their pros and cons, and what you need to know before purchasing one.
If you’re eager to read ahead, click here for the next article.
Bonus Tip
If you have insurance on your boat, reach out to your agent to see if your lower unit repair or replacement might be covered by your policy.
Get Started Today
You don’t need to wait for the rest of this course to find the perfect gearcase for your boat. Visit our website to explore our inventory of new and remanufactured lower units: Gearcase Selection.
Stay tuned for our next installment, and let’s keep you out on the water, where you belong!
