Need help with Yanmar SD20 problem

[Fluffflinger]

Hi

I needed to change one of the retaining bands on the top diaphragm of my saildrive.

So I purchased a replacement and a spare (it's a cat so thought it was prudent). I did this with a heavy heart as I had to sell my only child into slavery to pay for them ($127 for what is a 30odd inch stainless band, that was for two).

Problem is that they are fused into a continuous loop, not as I imagined a giant stainless zip tie. So fine for somebody who is changing the whole shooting match and has to remove the saildrive but no good for a retrofit or a repair.

I have found 316 stainless zip ties long enough but could only find vendors selling them in packs of 100. Having said that I could have purchased them for the same money and had 99 spares.

I assume that this band is essential to maintain the watertight nature of the upper diaphragm?

Any ingenious solutions that you guys can suggest?

Thanks, as ever in advance of your assistance.

Richard

[DotDun]

Originally Posted by Fluffflinger

Hi

I needed to change one of the retaining bands on the top diaphragm of my saildrive.

So I purchased a replacement and a spare (it's a cat so thought it was prudent). I did this with a heavy heart as I had to sell my only child into slavery to pay for them ($127 for what is a 30odd inch stainless band, that was for two).

Problem is that they are fused into a continuous loop, not as I imagined a giant stainless zip tie. So fine for somebody who is changing the whole shooting match and has to remove the saildrive but no good for a retrofit or a repair.

I have found 316 stainless zip ties long enough but could only find vendors selling them in packs of 100. Having said that I could have purchased them for the same money and had 99 spares.

I assume that this band is essential to maintain the watertight nature of the upper diaphragm?

Any ingenious solutions that you guys can suggest?

Thanks, as ever in advance of your assistance.

Richard

Been there! Done that!

Found a super long hose clamp that could split and be installed without removing the SD.

That seal is the secondary seal, although no less important from a maintenance point of view.

[Fluffflinger]

Thanks. To clarify it is a secondary seal and not the watertight seal for the top diaphragm????

Also having looked at it closely the width of the clamp needs to be to about 1/4in to pull the seal under the lip?

Guess if it's not essential to the watertight integrity of the system it wouldn't matter so much.

I found this, would it be fit for purpose???

https://www.pegparts.com/products/40...IaAuztEALw_wcB

[DotDun]

Originally Posted by Fluffflinger

Thanks. To clarify it is a secondary seal and not the watertight seal for the top diaphragm????

Also having looked at it closely the width of the clamp needs to be to about 1/4in to pull the seal under the lip?

Guess if it's not essential to the watertight integrity of the system it wouldn't matter so much.

I found this, would it be fit for purpose???

https://www.pegparts.com/products/40...IaAuztEALw_wcB

It's a secondary seal in case 14 (in the parts diagram) fails.

The seal (15) is held to the upper unit with band 16 on the inside. Band 17 holds seal 15 to the lower flange 13.

Yes band 17 is < 1/4" in width, but a wider hose clamp type band will work, it simply sticks up higher (and makes for slashing open fingers easier). Seal 15 sits on the outside of 13, I don't understand what you mean by 'the lip'.

It looks like what you found will work.

[Fluffflinger]

Dotdun

Thanks my friend I'm happy to proceed with the hose clamp fix.

Love this place and the people who are always here to help.

Best

Richard

[ggray]

Yeah, I'd hate to depend on that top diaphragm.

Not very thick or well secured.

[akprb]

I had two SD20s for a decade.

Replace the whole kit and caboodle every 5 years or so. I think Yanmar calls for an even shorter time.

I told the new owner this when we sold him the boat and he didn’t. A year later he wound up in the Caymans with the lower split and the upper leaking or otherwise barely holding on. I wasn’t there so don’t have the exact details.

That being said consider :-)

Cheap insurance, relatively!

[mindsofman]

Put a large heavy duty plastic Zip Tie on the
Top diaphram in Cuba,,still there with no leaking
Problems two months later in San Diego..
Those things are strong and can be pulled tight
With vise grips ,,have'nt broken one yet.
Not the ultimate answer but will get you there.

[out42]

I did the same as DotDun. Works fine. You get more water in the space underneath with leakage through from the top rather than seawater in form the bottom. The bottom seals are really super-durable so long as they are put on properly and not pinched, etc.