Yanmar 3JH3 with Kansaki Won't Go Into Gear when Hot

[LifePart2]

Recently we have been having problems getting our engine into gear - either forward or reverse - but only when the engine is hot.

It is fine when cold. Then, if we motor for a while and then try to anchor or dock we find that we can't get it into reverse or forward gear at all. On some occasions I would attempt to put it into gear, nothing would happen, and then after a little while it would suddenly 'take' and go into gear. Kind of seems like it is getting stuck.

Anyone have any suggestions?

Thanks

[pwilliams]

LifePart2:

It's been over a year since you posted your question. I found it when I was searching the site for the same problem.

I have a Yanmar 4JH2-HTE coupled to a ZM4A transmission. We're having a similiar problem, but it's only when shifting into foward, not reverse.

What was the final solution to your problem?

Thanks
Pat
Outbound 44

[LifePart2]

Hi Pat

It seems that this is a common problem with the Kazaki cone transmissions.

What happens is that the cone gets glazed/polished and thus loses grip. The solution is to dismantle the transmission, and then remove the glazing by grinding the cone with a lapping compound - the same paste stuff that is used for lapping engine valves so they sit properly in their beds.

It is, apparently, not a difficult job. Unfortunately, we were unable to dismantle our unit owing to a previous issue with it which had been resolved by someone putting locktite onto the drive shaft (another long story).

We have, in fact, only just had someone take the unit apart for us and do the repair job. It just us 200 euros in Sicily so, as you can see, it is not a big job provided someone knows what needs doing and doesn't talk you into buying a new gear box!

Until now we have been managing by changing the oil regularly, which certainly did help.

Curiously, having now had the job done (he says it has previously been done also) the mechanic is recommending we use ATF fluid, instead of the normal SAE 30, for this gear box. Seems odd, but he since he did the repair he must know what he is saying ,so we shall see. Since we are wintered now, we haven't tested it out properly, but it seems to be working much better when we tried it out at the dock.

If you have a Yanmar SD50 saildrive, there is a document from the Lagoon owners forum that describes exactly how to do the repair. I don't know if I can share that publicly, so pm me if you need the link.

Hope that helps.

Noel

[pwilliams]

Noel:

Thank you so much for your response. It is along the same lines of what I'm hearing from the local mechanics. We'll have to decide if we're going to repair this transmission or replace it. BTW, we don't have the sail drive.

Pat

PS, tried replying on my phone, only to send the message to the CF Help Desk.

Thanks again.