Yanmar SD40 diaphram issues

[Franciscarr]

Hi to all,
My first post!!
Having some issues and would be very grateful for any collective wisdom.
Beneteau 44.7 2005 build.
Yanmar 4Jh4E
SD 40
After 16 years decided to change the main diaphragm seal on the saildrive. Read all the stuff. Lower leg removed.
Attempting to remove the upper leg. Bolts turning. No access to whatever nut without cutting in to the glass. Thought it might be a plate but a pilot hole right next to the bolt just outside the drive is just glass. Suspect threaded inserts.
So will have to pull the engine, cut the heads off the bolts and find a solution.
Anyone seen this or have an idea how they attached the drive. Tried Beneteau USA. On hold for 30 mins and no answer. Tried Beneteau France and quote"everyone who worked on this boat has retired " which did make me laugh....
Thanks for your input.
Location Phuket Thailand....

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Picture help

[Franciscarr]

Hmm. Ill send tom but not much to see. The bolts holding down the upper saildrive are turning.
But thanks very much for your interest

[tkeithlu]

Hmmm. So you know that they imbedded some sort of threaded insert or nut in the fiberglass. It's rusted up and freely turning without the bolt loosening. That means surgery, but it needn't be a technological challenge. While it means getting the engine out of the way, I think attack from the top will be a better choice than from the bottom.

Depending on the length of the bolts, you may be able to drill them out, right through the "nuts" and out the bottom of the boat. The drill slipping off the bolt into the fiberglass may be a problem. Once you've got holes through the hull, at whatever size was necessary, you are free to make your own plate, washers, and nuts where they are accessible and sure. You might consider putting the bolt heads and fender washers on the underside of the hull with the nuts at the top.

This is going to be a nasty and frustrating task. I'm sorry.

Welcome to the forum.

[Franciscarr]

Thanks for an excellent reply.
Was hoping after id cut the heads off i might be able to pull the inserts. Ive thought about going in through the side . Coat hanger, string, threaded plate, stud sika. Pull up through saildrive for proper alignment. Let the sika set. Undo the stud and replace with hex bolt. Thought about going right through to the hull but had a bit of concern about compressing the structure. Drag is not an issue-my racing days are long gone...
Haha.
And thanks again.