TRANSMISSION SHAFT 346006

Function and Technical Context

The drive shaft is the component responsible for transferring torque from the reverse gear to the propeller, serving as the central mechanical link in the propulsion system of outboard and stationary engines. It operates within the lower unit, withstanding both torsional loads and radial forces during operation. A worn, bent, or excessively loose shaft causes vibrations in the propeller shaft, loss of efficiency in power transmission, and can damage the water seals, compromising the water tightness of the bevel gear assembly and exposing the internal gears to saltwater ingress. This replacement part, ref. 346006, is compatible with Johnson equipment and with engines from Mercury, Mariner, and MerCruiser, as well as the OMC range.

When should this part be replaced?

The most common symptoms of a damaged drive shaft are abnormal vibrations felt at the helm or in the hull at various speeds, a metallic noise coming from the lower unit, and visible play in the propeller coupling during a dry inspection. It is recommended to check the condition of the shaft during every seasonal maintenance or whenever the seals and bearings of the lower unit are replaced, as galvanic corrosion and abrasive wear are frequent causes of premature failure in marine environments. Replacing the shaft as a preventive measure upon detecting the first signs prevents serious failures in the propulsion system and costly repairs at the shipyard.

Equivalent manufacturer part numbers