Yanmar 3YM sticks in gear

[dovekie]

I would be glad of any advice about this.
Southerly 110, Yanmar3YM30, Yanmar KM2P-1 gearbox, 7 years old.
Always to date we have used the trick of putting the (stopped) engine in gear when sailing, to stop the prop' spinning.
Just set off for a few weeks in the Hebrides, and we find that if we engage gear - forward or reverse - with the engine off , the morse lever will not move the gearbox back into neutral. We can get back into neutral by starting the engine (in gear), when the morse lever will immediately and easily move back to neutral.
No problems moving between forward/neutral/reverse with engine running.
The gearbox is I understand a two shaft mechanical one. But I am no engineer, and don't understand what has happened. My concern is of course that I get stuck in gear with the engine running.
Currently we are tucked in Mallaig and safe. Any advice appreciated.
Thanks
Jon

 

[drydog]

If youre doing this whilst under way then the pressure of prop trying to rotate the gearbox and therefore the engine, may be stronger than the morse control trying to disengage gear.
Think of trying to change gear in your car without using the clutch.
Just my thoughts on it.

 

[RichardS]

If youre doing this whilst under way then the pressure of prop trying to rotate the gearbox and therefore the engine, may be stronger than the morse control trying to disengage gear.
Think of trying to change gear in your car without using the clutch.
Just my thoughts on it.

I don't ever engage gear when sailing but the issue of having to start the engine before the gearbox can be moved back into neutral has, I believe, often been discussed on the Forum. I don't understand why yours has only just started behaving like this but it seems to be fairly standard behaviour.

Richard

 

[Aja]

We snick the gearbox into reverse when the engine is off to stop the prop spinning, but we have a two bladed Gori folding prop. I wouldn't put it in gear with a non-folding or non-feathering prop. In order to continue your cruise I would be asking the question whether others with the same gearbox/engine configuration sail with the gearbox in neutral and allow the prop to spin with no adverse effects.

Donald

Donald

 

[jwilson]

My Jeanneau with Yanmar 3YM30 came with the specific instruction in the Jeanneau boat manual to put the gear into reverse when sailing. I used to do this and found that to get it out of reverse you had to start the engine first.

Then I found a Yanmar service advisory that said not to do this - it would damage the gearbox - see:-

DATE February 8, 2008 Dealers and OEMs
TO: All Marine Distributors
SUBJECT: Gear in Neutral While Sailing All MODELS:

All Sailboat Engines

We continue to get questions regarding the correct gear position while sailing with the engine OFF. This advisory is issued as a reminder; Yanmar requires that if sailing with the engine OFF (not running) the transmission shifter must be in the neutral position or internal damage to the gear or sail-drive will result. This damage will not be covered by Yanmar’s Limited Warranty. Please instruct customers and dealers who deliver the sailboat to the customer, of the correct (Neutral) position for the marine gear while sailing.

If the customer desires that the propeller shaft not spin while sailing, either a folding propeller, shaft break, or other suitable device may be used. However, Yanmar accepts no responsibility for the selection, installation, or operation of such devices. Please also refer to Marine service advisory “MSA07-001_Yanmar Sail Drive Propeller Selection” for additional information.

 

[awol]

Everyone I know with a KM2 gearbox uses reverse to stop the shaft/fold the prop. Mine withstood 30+ years of doing so. I have a skeg with a 2-bladed prop and locking it vertically is essential while racing. Only common problem I know of with this box is glazing of the forward cones causing delay in engagement - easily cured by lapping with grinding paste.

 

[vyv_cox]

Your symptoms are absolutely normal for this gearbox. We normally sail with the gear in reverse, after which the lever is immovable. Just start the engine and it will immediately be possible to put the gear into neutral. Our engine and gearbox have completed 2500 hours without complaint using this technique.

 

[dovekie]

Thank you all. It is particularly reassuring to get members first hand (and lengthy) experience. I managed to overcome the constraints of a tiny screen and low bandwidth to find some previous threads - Vyv, I think I have virtually your set up, incl' the autoprop. So clearly this is normal and not some harbinger of doom!
Thank you all again.
Jon

 

[Stemar]

If it's new, could it be that the gear cable is tired and getting stiff under load? We had similar symptoms and changing the cable fixed them

 

[greeny]

I would be glad of any advice about this.
Southerly 110, Yanmar3YM30, Yanmar KM2P-1 gearbox, 7 years old.
Always to date we have used the trick of putting the (stopped) engine in gear when sailing, to stop the prop' spinning.
Just set off for a few weeks in the Hebrides, and we find that if we engage gear - forward or reverse - with the engine off , the morse lever will not move the gearbox back into neutral. We can get back into neutral by starting the engine (in gear), when the morse lever will immediately and easily move back to neutral.
No problems moving between forward/neutral/reverse with engine running.
The gearbox is I understand a two shaft mechanical one. But I am no engineer, and don't understand what has happened. My concern is of course that I get stuck in gear with the engine running.
Currently we are tucked in Mallaig and safe. Any advice appreciated.
Thanks
Jon

My 3 ym was the same. I understand that it is normal. Just start in gear and then shift to neutral. Many posts in the past on this very subject. I've no doubt someone far more knowledgable will be along soon to fill in the details. I fact i'm certain that Yanmar have gone into print on this at a time in the past and said it's ok. I await the gurus on this subject.

 

[RichardS]

My 3 ym was the same. I understand that it is normal. Just start in gear and then shift to neutral. Many posts in the past on this very subject. I've no doubt someone far more knowledgable will be along soon to fill in the details. I fact i'm certain that Yanmar have gone into print on this at a time in the past and said it's ok. I await the gurus on this subject.

The gurus have already been and gone.

Richard