Mercury - Quicksilver 80W-90 Motorcycle Hypoid Gear Oil Gear & Transmission Protection High-Strength Hypoid Formula 8M0128380. Overview. There's something almost meditative about a bike that shifts cleanly and pulls with steady confidence. No grinding, no hesitation - just smooth engagement as the gears do their work beneath you. For riders with shaft-driven motorcycles or machines with separate clutch and transmission systems, the right gear oil can make all the difference. Quicksilver 80W-90 M