Yanmar and dripless shaft seals

[Clipper4730]

Just a quick question. A delivery captain told us that yanmar recommends freewheeling the prop under sail however will the dripless seals get enough water to lubricate and keep them cool?

Thanks in advance
Will

[roverhi]

I know that Yanmar has told people that their transmissions need to freewheel the prop. Have a hard time believing that in the Kanzaki transmissions for their smaller diesels. For one thing, the sounds of the rotating propellor gets really really really old after a few days on a passage. Made it one day out on the sail to Hawaii and then had to put the transmission in reverse. No issues after the sail.

Not sure the dripless seals have the issues with water lubrication as the old packing glands.

[Wotname]

The PSS dripless shaft seal does not need water injection at speeds below 12 kts so it should not be a problem with the prop freewheeling. Not sure about other brands.

Additionally a prop under power will be trying to suck water from the shaft when rotating and this suction is not present when the prop is simply freewheeling thus improving the lubrication when freewheeling.

Mine has never been an issue.