Yamaha - Gear 1 assy - 679-45560-00-00Yamaha Gear 1 Assy Lower Unit Gear Component 679 45560 00 00 Overview When youre dealing with power transfer issues in the lower unit, gears like this are usually where the problem shows up. This assembly plays a key role in transferring engine power down to the prop, and if its worn, youll feel it in performance or hear it under load. Ive seen gears like this cause noise, slipping, or loss of efficiency when they start to go. When everythings in good