Beneteau 40/KM35P trans problem

[JohnB40]

Hi Folks

2009 Beneteau 40
4JH4AE engine .... 1100 hours
Yanmar KM35P transmission (also called Kanzaki TTMC35P)

Works in reverse. When in forward it does not engage or only weakly. Then get revs up to about 1200 and it slams into gear. The cables are fine and the lever on the side of gear box moves easily and to the fullest extent.
Sounds like truly an internal problem. The oil (SAE 30 HD) is a bit black but doesn't smell burnt.
A friend suggests flushing numerous times with say SAE 10 to see if anything is stuck.
Any ideas?
thanks, John

[MARINE ENGINNER]

Originally Posted by JohnB40

Hi Folks

2009 Beneteau 40
4JH4AE engine .... 1100 hours
Yanmar KM35P transmission (also called Kanzaki TTMC35P)

Works in reverse. When in forward it does not engage or only weakly. Then get revs up to about 1200 and it slams into gear. The cables are fine and the lever on the side of gear box moves easily and to the fullest extent.
Sounds like truly an internal problem. The oil (SAE 30 HD) is a bit black but doesn't smell burnt.
A friend suggests flushing numerous times with say SAE 10 to see if anything is stuck.
Any ideas?
thanks, John

Do you mean that disengages by itself and back again?

M.E

[donradcliffe]

Flushing won't hurt and could save a bundle

[andreas.mehlin]

Have you tried to disconnect the cable from the saildrive and instead with your hand switch the gear? I had the same issue with my Volvo Penta. First I thought it was some kind of fault with the saildrive, but it was just an cable adjustment. Not visible.

[Rick01541]

Definately try changing the transmission fluid. Black means it is too old. Should change it the same schedule as your engine oil. I had trouble with my transmission that completely disappeared with a fluid change. It was black and had not been changed in a long while. If that doesn't solve it, check the cable.

[JohnB40]

Hi
To extend question. No, it doesn't come out of gear once in.
Been told it's the cone clutch that has become "glazed" and slippery. Repair shop might "lap" it ... which I guess means making it work (if not too worn).
Any experience on reliability of this.
Thanks, John

[MARINE ENGINNER]

Originally Posted by JohnB40

Hi
To extend question. No, it doesn't come out of gear once in.
Been told it's the cone clutch that has become "glazed" and slippery. Repair shop might "lap" it ... which I guess means making it work (if not too worn).
Any experience on reliability of this.
Thanks, John

From my experience if you lap it you will have a problem after maximum a month.Also yanmar recommends not to have your trans or saildrive while sailing engaged to stop your prop.
if you like to have a look last year i overhauled couple of these and i keep photos for my customers pm me your email to send you the service manual and photos