Yanmar Sail drive woes

[Mavis]

Thought I had sorted all my major winter jobs on the boat, a lot has gone wrong this year. Last weekend while servicing the engine ready for launch we noticed that a small 5mm wide stainless steel band had come away from the sail-drive. It looked a weird set up with no way of reconnecting it:

Page 5 - Item number 17, part number 196420-02740 in the diagram in the Yanmar Sail drive parts list which I cant seem to link to on here

I ordered a new one, £48.00 I think it was!. What is now obvious is that the old band was indeed broken as the tiny spot weld had failed. But I also realised to my absolute horror that I now need to remove the whole engine from the gear box to allow the new band to pass over the top and onto the rubber boot its meant to retain. Crikey, what a crap design?. I really do not want to do this now, and have searched for something like a 5mm Jubilee clip or similar to use instead but so far no joy.

I have been told that this inner seal is second or third in line and is only there as a last resort if the main seal broke, and apparently they don't. Has anybody else had this problem? and is there a way around this without removing the engine?
Thank you.

 

[RichardS]

Surely those bands no. 17 (shims) are inside the saildrive so you wouldn't see that one had come adrift?

If the band is the large one that goes around the saildrive to hull seal (17 on page 9) then you really should not use the engine. It is a double seal on the Yanmars but I would not recommend using it with only the bottom seal secured.

Edit .... I've never replaced a hull gaiter but I think that band is indeed continuous. If you can't get a large enough jubilee clip, you can buy metal band cable ties like these http://www.halfords.com/motoring/paints-body-repair/adhesives/halfords-metal-cable-ties-large-hfx419 or even the proper "use once" type which are used for CV joint gaiters like these http://www.ebay.co.uk/itm/10X-UNIVE...730278?hash=item1e79b20b26:g:UWwAAMXQwKdRbWow

You might have to join two together to form a large clip. You could also buy two large stainless jubilee clips and join these together to form one large clip.

None is ideal but I would go for two large stainless jubilee clips.

Richard

 

[Mavis]

https://www.dropbox.com/s/ld6fj9vgwofi6e4/IMG_7079.JPG?dl=0
If the link works it's this inner seal

 

[Skylark]

What a nightmare. Which version is it and how old/hours?

I had the same thoughts as Richard regarding Jubilee clips or metal cable ties.

Another option may be to use the existing band but modified to incorporate the tightening mechanism of a Jubilee clip, either spot or tack welded in place.

I agree with your sentiments, the very last thing in the mind of the boat designer was user maintainabliity when they started to use Saildrives. Great piece of design, lousy piece of engineering.

 

[RichardS]

https://www.dropbox.com/s/ld6fj9vgwofi6e4/IMG_7079.JPG?dl=0
If the link works it's this inner seal

Yes, that's the upper diaphragm seal clip. One of these in stainless http://www.jubileeclips.co.uk/products/multiband/ should be a perfect replacement or even a traditional stainless Jubilee clip http://www.jubileeclips.co.uk/products/original/.

With both of these the larger sizes will mean that you only need one clip.

Measure the diameter and width of the old clip then phone Jubilee or browse their website. I'm sure you'll find a replacement which is just as good (or better than!) the original.

Richard

 

[Halo]

Those bands are very flimsy and don't tighten like a jubilee clip. When installing them you pull them in and then fold the piece beyond the "buckle" back over on itself and slide a thin metal woggle over to hold it in place. As far as I could tell when I replaced my sail drive seals the bands would only do anything if the seal tried to slip out of its location - they do not seem to squeeze the rubber to make it seal. The point of saying this is that the band is not essential for the seal to seal but is there to stop things shifting.
If the old one is in place cant you use it as a mouse to pull the new one into position? If not can you drill a small hole in each end of the old one (in situ) and use a thin wire pulled between the holes to hold it tightish ?
If all else fails you can be reassure yourself that this seal is one level of protection higher then the Volvo equivalent and you can probably leave it until next winter - perhaps a planned job to replace all the seals and o rings if they are due

 

[Mavis]

Thanks guys for your help on this. Its a real bugger.

The replacement band needs to be only 5mm wide as it locates in-under a lip on the top plates housing. Anything wider and it would not hold the seal in place. After sleeping on the problem I now realise that if this secondary band has failed, when will the other more important unseen band fail?. I have also learnt that Yanmar do not give definite life spans for the Saildrive diaphragms, whereas Volvo do, and I believe its 8 years. Therefore as my boat is now eight years old I can only sensibly come to the conclusion that I have no real choice other than to replace the lot now.

I love my sailing and my boat, but spells like this make it seriously hard to warrant the continuous worry and expense, especially when it comes to convincing the wife???. Hopefully we shall all have a great summer and then it will all be forgotten.

 

[RichardS]

If the old one is in place cant you use it as a mouse to pull the new one into position? If not can you drill a small hole in each end of the old one (in situ) and use a thin wire pulled between the holes to hold it tightish ?

The OP says that the proper Yanmar one is supplied as a continuous band so it's not possible to "mouse" it.

Richard

 

[Halo]

Thanks guys for your help on this. Its a real bugger.

The replacement band needs to be only 5mm wide as it locates in-under a lip on the top plates housing. Anything wider and it would not hold the seal in place. After sleeping on the problem I now realise that if this secondary band has failed, when will the other more important unseen band fail?. I have also learnt that Yanmar do not give definite life spans for the Saildrive diaphragms, whereas Volvo do, and I believe its 8 years. Therefore as my boat is now eight years old I can only sensibly come to the conclusion that I have no real choice other than to replace the lot now.

I love my sailing and my boat, but spells like this make it seriously hard to warrant the continuous worry and expense, especially when it comes to convincing the wife???. Hopefully we shall all have a great summer and then it will all be forgotten.

Sensible !
Yanmar now firmly recommend changing seals after 5 years although few people actually do so
P.M. me if you want a copy of the notes I made when I changed my Yanmar saildrive seals

 

[Slipperman]

This happened to my Yanmar Saildrive when the boat was only 6 months old! Yammer offered to replace it (by removing the engine etc!) under warranty, but I was really reluctant to do that and my local Yanmar engineer told me that it was not at all important and that a plastic cable tie (not pulled too tight, because it is not designed to be tight) would suffice. It has lasted several years and many thousands of miles sailing and motoring!