Mercury - Quicksilver Shift Actuator Control System Component Hardcoat Anodized and Aluminum Construction 8M0124413. Overview. There's a moment every boater knows - when you ease the throttle forward, feel the shift engage, and the boat responds exactly the way you expect. That steady, predictable movement brings a kind of quiet confidence you can't fake. When your shifting system is dialed in, the whole ride feels smoother, whether you're threading your way out of a busy marina or running wide