Thanks to those who contributed to my last queried on sailing with the transmission in neutral. Most say check with your manufacturer. Well I have not been able to find that information. My drive is a Kanzaki KM2P-1. There are no warning labels advising weather or not to freewheel the prop shaft. And nothing in my documents supplied with our Catalina C320. Any information would be appreciated !! Regards
Neutral or not? Kanzaki KM2P-1
- Thread starter Brahmany
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My training is to reverse gear when the engine is not running. The reason is that most transimssions are lubricated by an oil pump when the engine is running. So if the transmission is in nutral and the engine is not running - then the transimmsion is not being lubricated and so it is not a good idea to let the prop turn the unlubricated gears. I practice this even with my outboard engine.
My feeling about the neutral/reverse issue boils down to the fact that there seems to be NO harm in putting it in reverse regardless of any thing else. There are questions about leaving it in neutral.
So why not put it in reverse and you should be safe. The ONLY thing that seems to be a problem with the "reverse" issue is the fact that you can sometimes not get it back in neutral without starting the engine and you may also be 1/10 of a kt. slower, but that is also in question.
So why not put it in reverse and you should be safe. The ONLY thing that seems to be a problem with the "reverse" issue is the fact that you can sometimes not get it back in neutral without starting the engine and you may also be 1/10 of a kt. slower, but that is also in question.
According to my manual and Massey is to leave it in neutral. Do not put it into reverse. Last year I sent my 90 hour transmission to Massey for repairs. I thought the thrust bearing had gone. What they found was wear on the horseshoe clutch (I think I got that right) that was replaced. They asked me if I sailed with it in reverse. I said yes. The said "Don't do that"!
The Kanzaki KM2P-1, the KM2A and KM3A specifically are cone clutch transmissions and do not have oil pumps in them. When the engine is running, even in neutral, the bearings and gears are lubricated by the lower gears dipping into the oil in the bottom of the transmission case and moving a small amount of oil up to the top gears and bearings. When the prop is freewheeling in neutral, the gears do not turn. The lower shaft and cone driver (but not the clutch) turns and the lower shaft bearings turn. The lower bearings have essentially no load on them and are lubricated by dipping the lowest rolling element into the oil level in the transmission case. It is crucial to have the oil level correct. Freewheeling in neutral is OK on these transmissions IF the oil level is correct.
If put into reverse, the cone clutches engage and lock the prop; no problem, as Steve says.
If put into forward while sailing with the engine off, the forward cone clutch will not engage fully because it is being driven by the prop shaft and not the engine gear. It will slip and eventually wear out. There are some other transmissions that are the same and there are some that are very different from these; I am not familiar with any but the specific ones that are listed above. The post was a question about one of the listed transmissions.
If put into reverse, the cone clutches engage and lock the prop; no problem, as Steve says.
If put into forward while sailing with the engine off, the forward cone clutch will not engage fully because it is being driven by the prop shaft and not the engine gear. It will slip and eventually wear out. There are some other transmissions that are the same and there are some that are very different from these; I am not familiar with any but the specific ones that are listed above. The post was a question about one of the listed transmissions.
I notice the "1/10 kt speed loss" comment.
My 05H36 has a fixed 3-blade prop (Yanmar 3YM30 w/ Kanazaki cone-clutch xmssn).
Fixing the transmission in reverse results in a 0.5 kt loss in boat speed vs letting the prop free-wheel.
In light airs, the difference between 4kts and 3.5kts is the difference between transit times my wife will (barely) tolerate under sail, vs those she won't and demand I start the engine. Non-trivial difference to me.
Fair winds,
Al - s/v Persephone
My 05H36 has a fixed 3-blade prop (Yanmar 3YM30 w/ Kanazaki cone-clutch xmssn).
Fixing the transmission in reverse results in a 0.5 kt loss in boat speed vs letting the prop free-wheel.
In light airs, the difference between 4kts and 3.5kts is the difference between transit times my wife will (barely) tolerate under sail, vs those she won't and demand I start the engine. Non-trivial difference to me.
Fair winds,
Al - s/v Persephone
I don't know if the clutch unit (transmission) for my Yanmar YSM12 is made by Kanzaki. Does anyone with YSM8 or YSM12 experience know if it is OK to free wheel while sailing? There is no information in the YSM8/12 manual but it uses CI motor oil and from the drawings it looks like the clutches are flat plates.
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