Yamaha - Gear 1 assy - 6E5-45560-01-00Yamaha Gear 1 Assembly Lower Unit Drivetrain 6E5 45560 01 00 Overview If youve ever torn into a Yamaha lower unit, you know the gears are where everything either comes togetheror falls apart. This Gear 1 Assembly plays a key role in transferring power smoothly from the driveshaft to the prop, especially when youre shifting under load or cruising for long stretches. Its the kind of part you dont think about until shifting gets rough or you start