Problem with Yanmar SD40

[doug1720]

I have a Beneteau First 44.7 and have a problem with my Yanmar SD40 saildrive.

I would like to know if this has happened before and the next steps. Can I rebuild or do I need to replace?

I went forward in gear and heard a big noise. We got a tow.

On inspection the upper drive assembly had come through the top of the saildrive, dislodging the dipstick!

I have attached some photographs. I have removed the gear shift but cannot get the engine drive to push back into the engine (I have taken the 4 nuts back on the threaded stubs) but no movement.

Any help appreciated.

[Panache5000]

Refer to the photo showing the nuts. You need to lever/push the studs towards the engine, allthe way up to the nuts. The assy dhould then come out.
Looks like damage is due to lower retaining

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[Captain Bill]

I agree that you may need a lever or a piece of wood and a rubber mallet. The assembly you are trying to remove has o-rings sealing it and they can take a little force to break loose. I'm a bit concerned that the bevel gears may be jammed with that assembly being so far out of position. Normally one needs to move the pilot shaft forward to disengage the bevel gears before the upper drive assembly will lift out. The fact thet it busted through the cover would suggest that something is seriously broken. The only thing that I can imagine that would produce enough vertical force to bust through the housing is the bevel gear on the pilot shaft. All of the other parts rotate on the horizontal. If you busted that gear you will need to remove the pilot shaft assembly not just slide it forward. This can be done with the boat in the water, if neccesary, and if you have enough room to slide the engine forward about 6 inches. I had to have one rebuilt about 2.5 years ago, because it was a 3 month wait to get a new one. It only cost me $500 less than a new unit. You don't say where you are, but apparently Yanmar doesn't ship saildrives to the US unless they are attached to a new engine. Just a sail drive had to be shipped from Japan. That may have changed since the SD60 came out. Thinking about what you are facing you might want to haul the boat anyway. Depending on what's broken there might be a lot of metal debris that got down into the lower unit and may have to be cleaned up.

[Panache5000]

Like i tried to say before 1/2my reply wss lost....
The damage is most likely due to the failure if the lower 2 round C ring retainer and or lower collar.
This failure would allow the centre shaft to be "pulled" up by the lower cone due to the spiral in the shaft.

The bevel gears are more than likely still ok. They are inside the inner case assembly, with substantial bearings for

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