What is the correct gear to use when sailing with a boat equipped with a ZF “MS” mechanical transmission (commonly used on Universal, Vetus, Volvo, Kubota diesel engines, along with many others)?
The ZF (formerly Hurth) “MS” (mechanical/sailing) marine transmission fitted to many sailboat diesel engines is designed to allow the propeller to freewheel while sailing to reduce propeller drag (usually propeller drag slows the boat by around .2 – .5 kn. Therefore when the boat has a fixed blade propeller the transmission should be in neutral while sailing. When the boat has a folding or feathering propeller the transmission should be in reverse to lock the propeller shaft so the folding or feathering propeller can function properly. NEVER SAIL WITH THE TRANSMISSION IN FORWARD GEAR… IT WILL BURN OUT THE TRANSMISSION CLUTCH PLATES. No matter what type of propeller is fitted to the boat always leave the propeller in neutral when leaving the boat so that there is no chance of the propeller turning in the wrong direction due to a tidal or river current and burning out the transmission clutch plates even when the boat is not being used. From the ZF Marine Operating Manual: “When the eng
