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mark lennoc · 05-08-2019, 15:34

I am suddenly experiencing what I think may be the start of my clutch slipping. I leave the dock and have plenty of engine RPM’s but no torque and can only do 1knot max. After about 30 seconds the speed picks up and all is normal for the duration of the motoring period. The whole process can repeat once sailing is done and I want to motor in. Or not, sometimes everything runs great.
I have seen on other posts about Yanmar sail drives and similar problems with the cone style clutch. Before I went ahead and removed the tranny and clutch I am wondering if anyone out there might have had a similar experience with this issue.
The engine is a Yanmar 3JE series with a Kanzaki tranny.
Thanks

**a64pilot** · 07-08-2019, 07:05

That does sound like a slipping clutch.
What transmission? Does it have clutch packs or cones?
Does the transmission use Dexron? Is it dark and have a burnt smell?

mark lennoc · 07-08-2019, 07:41

The tranny has a cone clutch and I read that they are prone to glazing and subsequent slipping. No burnt smell in the oil. The transmission is a Kanzaki KM35.

Thanks for your interest.

kenbo · 07-08-2019, 07:57

It does sound like the cone clutch is slipping. I'd avoid high rpm running while cold and slipping, you're most likely shedding small metallic particles into the oil.

You may want to check the trans cable adjustment to see if you can alleviate some of the slipping.

The problem in many cases is caused by locking the trans in reverse while sailing. The design of a cone clutch is to drive an opposing rotating part not to resist the rotating force of the shaft.

mark lennoc · 07-08-2019, 08:15

Thanks for the info about sailing in gear (reverse) which is what I have been doing. I did not see any metal particles in the tranny oil.
Other than remove the clutch and transmission, I don’t know what else to do. I live on the west coast and because of the currents I could get into trouble pretty quick if the clutch didn’t cooperate.

kenbo · 07-08-2019, 08:29

Even stop gap methods require splitting the case so in most cases where parts are available it's makes sense to replace the consumable parts.

You may want to motorsail at a low rpm half hour or so before approaching any need for motorized power.

kenbo · 07-08-2019, 08:33

This may be helpful http://jeanneau.proboards.com/thread...r-transmission

**a64pilot** · 07-08-2019, 08:49

I edited the above post so the link would work.

I believe there is a fix out by a third party to fix the cone clutch slipping issue. Not sure if it’s just for the saildrives or not though.
I think it’s a simple fix, a bushing or shims or similar etc.

mark lennoc · 07-08-2019, 12:54

Thanks so much for sending along the link. I will give it a try tomorrow, I hope. We will see what happens and I will post the end result.

Thanks again to everyone who has contributed to my dilemma.....mark

**Wotname** · 07-08-2019, 16:09

Quote:

Originally Posted by mark lennoc

Thanks for the info about sailing in gear (reverse) which is what I have been doing. .......

FWIW
As others have posted upthread, Yanmar considers this to be a big nono for many of their transmissions although you may have to check with them about your particular transmission. Typically causes cone clutch wear.

mark lennoc · 07-08-2019, 19:38

Well, I just got back from my boat. The local mechanic came down for a look and said he would change the oil first before digging into the transmission and clutch. The boat is new to me, 2005 Beneteau 373, so I had no idea what oil is in it or when it was last changed.

I did ask about sailing with the throttle in reverse and the mechanic couldn’t see how that would be a problem.

I have had boats now for over 40 years but was without one for the last 6 years. I had completely forgotten one of the boating maxims and that is there are so many opinions about everything to do with a boat. It makes my head swim!

Thanks again for your help.

Mark

**a64pilot** · 07-08-2019, 19:57

Trust us, if you have a cone clutch, you MUST sail in neutral, or damage like you describe will occur

Compass790 · 07-08-2019, 20:06

Quote:

Originally Posted by mark lennoc

Well, I just got back from my boat. The local mechanic came down for a look and said he would change the oil first before digging into the transmission and clutch. The boat is new to me, 2005 Beneteau 373, so I had no idea what oil is in it or when it was last changed.

I did ask about sailing with the throttle in reverse and the mechanic couldn’t see how that would be a problem.

I have had boats now for over 40 years but was without one for the last 6 years. I had completely forgotten one of the boating maxims and that is there are so many opinions about everything to do with a boat. It makes my head swim!

Thanks again for your help.

Mark

DON'T listen to the "mechanic" re sailing with gearbox in reverse, listen to A64 pilot & Wotname or get a workshop manual & confirm for yourself.
If you are really lucky? the transmission may have the wrong fluid in it.