VERTICAL SHAFT S 66T-45501-01

Function and technical context

The vertical shaft is a fundamental component in the power transmission of Yamaha outboard and sterndrive motors. This shaft is part of the vertical transmission system, responsible for transferring the rotation of the engine to the propeller, allowing the force generated in the crankshaft to be efficiently channeled towards the propulsion of the boat. Its correct operation is essential to maintain the mechanical stability of the propulsion assembly and guarantee that the engine's power is translated into effective movement. A worn or damaged vertical shaft can cause excessive vibrations, loss of traction, and in severe cases, complete lockup of the propulsion system.

When to replace this part?

The vertical shaft requires replacement when symptoms such as abnormal vibrations are detected during navigation, lateral movement of the propeller, visible wear on the support points or if a noticeable decrease in engine response is observed during acceleration. It is recommended to check the condition of the shaft during each seasonal maintenance, paying special attention if the boat frequently operates in shallow water or with impacts against the bottom. Preventatively replacing the axle when the first signs of wear are detected prevents more costly secondary damage to the gearbox and powertrain.

Equivalent manufacturer part numbers