|I get to scrap the rust off of that. Yay!|
But why do I care about rust on the transmission? What essential function does it perform? (Once again, it's shocking that I don't know this stuff!)
Not surprisingly, it's both remarkably simple and potentially very complex once you delve into concepts like torque, which I most definitely will not. The transmission sends the energy that the engine produces to whatever device does the actual work such as the wheels on a car or, in our case, the propellor. Essentially, it's just a metal box full of gears that turn with the crankshaft. When the engine creates power, as I described here, it turns the crankshaft, which has a gear on the end of it that connects to a gear on the transmission ** (See note). These gears turn the gears inside the transmission, which turn the propeller shaft, which then turns the propeller. I know this sounds like the inside of a Swiss watch, so please check out this excellent diagram of what a simple transmission looks like. I found it incredibly helpful. Here's a more complicated diagram from my new favorite book, "The Care and Repair of Small Marine Diesels:"
**Note: Vlad keeps telling me that transmissions vary, so please keep in mind that I'm speaking in very general terms and that I'm certainly not an expert on different types of transmissions. That's speaking the obvious, I know.