Reverse

[gonsailing]

My 2002 Hunter 356 began experiencing issues recently with not going into reverse. I have a Yanmar 28hp engine. It goes into Fwd find however no thrust in reverse. The gear shift seems to work fine with the shaft spin increasing with throttle in fwd and reverse...but no thrust in reverse.
Suspecting a glazed clutch we have tried replacing the ATF with diesel and an additive to dissolve the deposits and get the cluthc to re-engage. No luck so far.
Has anyone else experienced this issue? Words of wisdom or advice? Thanks.

 

[Butch23065]

I'm not sure if your transmission is a cone drive, but if it is, it could be your linkage is out of adjustment. My 34' Pearson would jump badly around 1500 RPM in forward because it was not going all the way in gear. If I ran it wide open it would smooth out because of the added pressure from the prop and shaft.
Take the linkage loose and shift it in and out of gear at the transmission. Yes, it will take two of you. You can do it at the dock, just be sure you are secured well.

 

[chuckwayne]

your transmission is a kanzaki cone clutch unit and uses 30 weight non detergent engine oil, not atf or diesel(??). I'd flush out the transmission several times and put the correct oil in.
this is the unit yanmar recently said should be left in neutral,not reverse like they said before-so it's possible you have cone damage.

As Butch said, check the linkage adjustment first.

 

[rfrye1]

So ChuckWayne,

I have a '98 H376 w Yanmar 3JH2E with Kanzaki transmission. I know Hunter changed their minds about leaving the tranny in neutral now, not reverse. Was it because of the different type of transmission?

I still put my trans in reverse while sailing. Otherwise the rotating shaft and little bit of vibration sailing in neutral drives me nuts! Yea I know I can rig up some of shaft brake, but its easier in reverse. I've been doing it for 13 yrs w this boat. Hmmmm....

 

[Mcprade]

We have been there and done that. We also have a 356 on Lake Champlain and had the same problem. The oil should be 30 non detergent motor oil. However, the damage has been done. We removed the transmission, not too difficult, and sent to Mac Boering in MA. It did cost a $1000 four years ago. We have not had a problem since. We are pretty sure our our folding prop caused the issue. We have sinced replace with a feathering prop. Our shaft would just spin with the folding prop. Hope I am not bursting your bubble.

 

[Charles Erwin]

Seems logical that the transmission is fully engaged because Gonsaliing says that the shaft is turning in reverse position. Since the shaft is turning in reverse maybe the transmission/clutch engagement is not the problem.

Consider:

Is the propeller a feather or folder type? If so - then are the propeller blade mechanisms worn thus reverse is not possible?

If it is a fixed blade propeller then has the shaft to prop key sheared? If so the propeller will work in forward because the propeller moves toward the shaft taper thus increasing joint friction at the taper in forward -- but it will decrease shaft friction at the shaft taper in reverse because the propeller moves away from the taper in reverse.

Charles

ps Do let us know what it turns out to be

 

[chuckwayne]

rfry1,
Yanmar issued the advisory, not Hunter.... as far as I know, all of those Kanzaki boxes are cone type - maybe someone else can chime in here???
I would expect that the wrong lube could cause slippage, and not necessarily the same in fwd and reverse.
Charles brings up some good points- it could be the prop if it"s a feathering/foldering

 

[PKFK]

Hmmm - can someone please clarify ?

I have a 2007 H36 with the yanmar 3ym30 engine. The boat is fitted with a Variprop.

The manual for the Variprop says to briefly run the engine in reverse and then hit the kill switch in order to feather the Variprop for sailing.

Once I do this I try to shift the engine into neutral - but sometimes it is stiff and I don't force the shifter - leaving it in reverse instead of neutral - but with the prop feathered.

Is this a problem for the yanmar engine ? It seems the Variprop instructions are opposite to the yanmar instructions ????

Any one have more info on what we are supposed to do for this configuration of engine and prop ?

 

[Jake N Eggs]

Hmmm - can someone please clarify ?

I have a 2007 H36 with the yanmar 3ym30 engine. The boat is fitted with a Variprop.

The manual for the Variprop says to briefly run the engine in reverse and then hit the kill switch in order to feather the Variprop for sailing.

Once I do this I try to shift the engine into neutral - but sometimes it is stiff and I don't force the shifter - leaving it in reverse instead of neutral - but with the prop feathered.

Is this a problem for the yanmar engine ? It seems the Variprop instructions are opposite to the yanmar instructions ????

Any one have more info on what we are supposed to do for this configuration of engine and prop ?

I also have a variprop. It can be difficult to get out of reverse when the engine is stopped if it is left in reverse for a couple of seconds. I stop the engine in neutral and then quickly select reverse and immediately return to neutral. This seems to have solved the issue.

I think what is happening, mechanically, is that the prop is turning when the engine is shut down. By selecting reverse the shaft is stopped and the blades are feathered by the water flow. By shifting quickly into reverse and then back to neutral the shaft starts to slow and there is still a little rotation left to allow the transmission to shift back to neutral easily. If the transmission is left in reverse until the shaft stops completely it is hard to get out of reverse. The slowing shaft is enough to start the blades feathering and the water flow does the rest.

You could probably get the same result if you shut down in reverse and select neutral just before the engine stops completely.

Ultimately I think that the transmission will shift easier if there is shaft or transmission rotation.

 

[Hannah Quinn]

I do the same with the desired result. I shut down the engine in neutral, then shift into reverse and back to neutral. It allows my prop to feather into a neutral position.. No thumping under sail.

 

[Mcprade]

I do the same with the desired result. I shut down the engine in neutral, then shift into reverse and back to neutral. It allows my prop to feather into a neutral position.. No thumping under sail.

We also do the same

 

[PKFK]

Thanks for the tip - we will try it out.