The Great Rotation Debate

[Ralph Johnstone]

Gordon,It appears that the Great Debate over sailing a Yanmar engine in reverse or neutral is once again in full swing. I don't seem to remember your addressing this matter before.If you have addressed this before could you please steer us to the article or if not ............ could you please settle it, once and for all, as the final last word, and never again hereafter:"Does sailing with a Yanmar in neutral, and the shaft free wheeling, cause damage to the transmission due to a lack of lubrication ?"Thanks,s/v Island Hunter

 

[Gordon Torresen]

Gear rotation

The lubrication within the reversing gears used on Yanmar engines is a splash type. The gears are always on the shafts and in mesh and the gears are the ones that make the splash. Hence, lubrication is not a problem if the engine is driving the shafts or if the propeller is. Yanmar says it doesn't matter if you freewheel or shift the gear to reverse to stop the rotation. There is the question of "lubricated wear". If you freewheel, the gears and bearings within the reversing gear are turning, albeit without load. Then there is the shaft packing and the cutless bearing that are wearing.  Then comes drag. Some say that there is less when fixed and others say less when spinning. If you can hide the prop blades behind some deadwood, fixed is certainly better. I think I would pop it into reverse while sailing. Then again, I would remove the anemometer from the masthead during the off season.