I have twin 4JH57 Yanmars with SD60s. I'm at 280 hours and one of them has developed a loud gearbox
. It's intermittent in that if I start it up and it doesn't make the noise
, it won't start making the noise
but if I start it and it makes the noise, it will continue doing so.
It sounds like partially engaged gears and sounds the same in forward and astearn and increases with revs. It does not make the sound in neutral.
tech was just aboard (I'm in Grenada) and of course it wouldn't make the noise although he said it was louder than it should be.
The plan is to have them pull the assembly and take a look and hopefully do what needs to be done while we're in the water
I'm wondering if anyone has heard of this issue? Anything else it could be? We have flexifold props, could these be making the noise?