Yanmar 3ym30 and Kanzaki KM3V transmission oil leak

[trialframe]

I have this engine & gearbox on my Nordhavn 43 for the wing engine.
It suffers from under use as it's (thankfully) never been deployed in anger.
Problem is there's a leak from the V drive gearbox which is occurring constantly (when not running).
It seems to coming out underneath where the prop shaft runs aft out of the V drive.
Anyone else had this issue & what's the procedure to repair - new shaft seal?

 

[WildGoose]

I have this engine & gearbox on my Nordhavn 43 for the wing engine.
It suffers from under use as it's (thankfully) never been deployed in anger.
Problem is there's a leak from the V drive gearbox which is occurring constantly (when not running).
It seems to coming out underneath where the prop shaft runs aft out of the V drive.
Anyone else had this issue & what's the procedure to repair - new shaft seal?

I have the same configuration and problem. Did you find a resolve? Thanks

 

[Skookum1]

We have the same Wing Engine and Gear Box on our Nordhavn40. We have a leak too from the V drive gearbox too, even when its not running, We are trying to find the two seals! We haven't had much luck! I did write Yanmar an email. we want a diagram too of the KM3V transmission and I can't seem to find it anywhere online? or a parts catalogue for it would be nice. Derek thinks he can maybe repair it without hauling the boat out of the water. Jen

 

[trialframe]

As the leak on my gearbox is relatively small, I've still not done anything about it. It seems to be a common problem on the boats I personally know about. I'll be speaking to another fellow N43 owner in the near future and will post any further information.

 

[VicS]

We have the same Wing Engine and Gear Box on our Nordhavn40. We have a leak too from the V drive gearbox too, even when its not running, We are trying to find the two seals! We haven't had much luck! I did write Yanmar an email. we want a diagram too of the KM3V transmission and I can't seem to find it anywhere online? or a parts catalogue for it would be nice. Derek thinks he can maybe repair it without hauling the boat out of the water. Jen

Parts diagrams and lists for the KM3V can be found here
https://j109.org/docs/Yanmar-3GM30-parts-catalog.pdf

Figs 102 to 110 are the KM3V

The seals which I think you want are shown in Fig 103

I would try a bearing stockist to see if they can match them

 

[WildGoose]

Bring the seal and bearing to a specialty wholesaler and they should be able to match.
If you have gone far enough to pull the seal replace the bearing same time!