Cobra750
New member
Hi All. has anyone ever heard of problems with the hull sealing ring for sail drives failing either gradually or catastprohically? Thanks
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do sail drive sealing rings ever leak?
- Thread starter Cobra750
- Start date
claudio
New member
I think Volvo advise that they are replaced every 5 (or 7) years. It may also be a condition on your insurance policy.
I don't know what measures you could take to prevent sinking if the sail drive leg were to be hit by a solid object.
I would need some serious convincing to buy a boat with a sail drive configuration.
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I don't know what measures you could take to prevent sinking if the sail drive leg were to be hit by a solid object.
I would need some serious convincing to buy a boat with a sail drive configuration.
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PeterGibbs
New member
Not my job to persuade anyone to buy a sail drive but I am converted, so avert your eyes!
The gaskit is formed to take a lot of movement - much more than could be accommodated by a regular shaft. BUT it does have to be replaced on a precautionary basis every 7 years. If it shows signs of premature failure, softness or dimpling etc, the boat has to be lifted immediately. The S leg is the largest hole in the hull by a long way; failure in the water is not to be contemplated!
PWG
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The gaskit is formed to take a lot of movement - much more than could be accommodated by a regular shaft. BUT it does have to be replaced on a precautionary basis every 7 years. If it shows signs of premature failure, softness or dimpling etc, the boat has to be lifted immediately. The S leg is the largest hole in the hull by a long way; failure in the water is not to be contemplated!
PWG
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claudio
New member
I know lots of people with sail drives, never heard of any catastrophic failure. I'm led to believe that most if not all of the seals are double skinned and some have a water detection system between the seals. They've been around for quite a while now and if there was an inherent problem in the design, I'm sure that it would be much publicised. It's just personal preference, I would prefer not to have a big hole cut out in the worse possible place for water entry. At least with a shaft drive it is possible to stem the flow of water with a bung if the unmentionable happened.
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tony_brighton
New member
I asked Volvo that question a while ago - their engineer said they'd never had an incidence of catastrophic failure.
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Talbot
Active member
I have heard of this. IIRC the new Yanma system is a double seal with a warning if water penetrates between the seals.
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extravert
New member
I have never heard of this either. Bukh saildrives also have a double seal with a water detector between the seals.
<hr width=100% size=1>One day, I hope to own a real boat.
<hr width=100% size=1>One day, I hope to own a real boat.
Stemar
Well-known member
Re: Replace every 7 years
I read once of a modern boat where the sail drive gasket has to be replaced after 7 years. Fine, it's a bit of a pain, but it's routine maintenance. Unfortunately, to do this the gearbox had to be removed, which involved taking a chainsaw to the rear bulkhead...
When this was pointed out to him the salesman wasn't put out . Apparently, his reaction was along the lines of, "Our buyers don't keep their boats that long, so where's the problem?"
The article didn't name the boat, which is a big shame, but I think it was a continental marina hopper.
Worth checking before you shell out on a boat with a saildrive, methinks.
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I read once of a modern boat where the sail drive gasket has to be replaced after 7 years. Fine, it's a bit of a pain, but it's routine maintenance. Unfortunately, to do this the gearbox had to be removed, which involved taking a chainsaw to the rear bulkhead...
When this was pointed out to him the salesman wasn't put out . Apparently, his reaction was along the lines of, "Our buyers don't keep their boats that long, so where's the problem?"
The article didn't name the boat, which is a big shame, but I think it was a continental marina hopper.
Worth checking before you shell out on a boat with a saildrive, methinks.
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extravert
New member
Re: Replace every 7 years
That's just really bad design, irrespective of whether a saildrive had been used or not. The bulkhead would have to be dismantled for gearbox maintenance as well as gasket replacement. Some engines are well known for chewing up their engine/gearbox coupling a bit too quickly, aren't they?
<hr width=100% size=1>One day, I hope to own a real boat.
That's just really bad design, irrespective of whether a saildrive had been used or not. The bulkhead would have to be dismantled for gearbox maintenance as well as gasket replacement. Some engines are well known for chewing up their engine/gearbox coupling a bit too quickly, aren't they?
<hr width=100% size=1>One day, I hope to own a real boat.
philwebb
Member
Re: Replace every 7 years
My boat has a Volvo saildrive and two seasons ago I changed the rubber and the
metal clampring. The reason for this was corrosion of the ring due to an exhaust leak.
I am convinced that it was the first time that the rubber had been replaced in thirty
years, and it was still serviceable! I have also seen a boat with a saildrive lifted out
of the water with the strap under the saildrive. It was put back in the water without
delay, but the seal did not leak. (Volvo saildrive) . I have every confidence in my
saildrive unit. It is difficult to envisage a situation where it could take a knock as
the keel protects it at the front and the rudder would have to be knocked off at the
back before it was touched.
Regards, Phil
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My boat has a Volvo saildrive and two seasons ago I changed the rubber and the
metal clampring. The reason for this was corrosion of the ring due to an exhaust leak.
I am convinced that it was the first time that the rubber had been replaced in thirty
years, and it was still serviceable! I have also seen a boat with a saildrive lifted out
of the water with the strap under the saildrive. It was put back in the water without
delay, but the seal did not leak. (Volvo saildrive) . I have every confidence in my
saildrive unit. It is difficult to envisage a situation where it could take a knock as
the keel protects it at the front and the rudder would have to be knocked off at the
back before it was touched.
Regards, Phil
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FullCircle
Well-known member
Re: Replace every 7 years
I have an OLd MB2-50S, the 7.5 hp unit. It is 1978 vintage. As I have an exhaust gasket leak, the engine is being pulled. I will clisely inspect the seal, but am not expecting disasters, as it does not leak currently. As the boat has had apparent haphazard maintenance over the years, and thus has probably had no real attention for ages, I am convinced that I will be able to make it serviceable for another few years. I will report back the findings.
I agree with the previous post that mine sits behind the keel and well in front of the rudder. Besides it is quite well bolted down with a cover over the inside, with a good deal of movement available to absorb/deflect shock loads.
I am a fan of the arrangement, and I cant find apocryphal tales of failure either.
Jim
<hr width=100% size=1>Second Chance - First Love. Hasn't anybody else got a little Jouet? I feel lonely!
I have an OLd MB2-50S, the 7.5 hp unit. It is 1978 vintage. As I have an exhaust gasket leak, the engine is being pulled. I will clisely inspect the seal, but am not expecting disasters, as it does not leak currently. As the boat has had apparent haphazard maintenance over the years, and thus has probably had no real attention for ages, I am convinced that I will be able to make it serviceable for another few years. I will report back the findings.
I agree with the previous post that mine sits behind the keel and well in front of the rudder. Besides it is quite well bolted down with a cover over the inside, with a good deal of movement available to absorb/deflect shock loads.
I am a fan of the arrangement, and I cant find apocryphal tales of failure either.
Jim
<hr width=100% size=1>Second Chance - First Love. Hasn't anybody else got a little Jouet? I feel lonely!
norseman
New member
I have Volvo 110S saildrive fitted behind the keel and in front of the rudder as the others. Never had a bit of bother with it, it still looks as good as new. I reckon if the gearbox oil is changed annually and checked frequently, it is a very reliable system of drive. much more so than a lot of other gearbox drives and stern glands. There is also an outer membrane which glues on to the outside of the hull with a 50m/m broad glueing area round it and which is a really tight fit over the saildrive leg. This membrane has a 6m/m hole in it, I presume to let the water in and equalize the pressure between membranes, and as such would have to be damaged first before you got to the inner main membrane seal. It would also restrict the amount of water that could actually get in if per chance the main seal failed, which I to have never heard of. Also I believe that some of the better designed engine compartments are sealed areas with air intake tubes coming down from deck level which means that the compartment if the seal totally failed(hard to imagine) the water level would only go to the same level as that outside the boat.
All IMHO
Norse.
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All IMHO
Norse.
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philwebb
Member
Re: Replace every 7 years
Jim-look closely at your exhaust bend . I had a leak down there and was convinced that
it was the gasket or the rubber exhaust hose. What it turned out to be was a crack
in the cast iron exhaust. Do you have to take out the engine to get to yours? Mine
is quite easy to get to and remove. If you take out the saildrive I wouldn`t re-use the
rubber ring though.
Regards, Phil
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Jim-look closely at your exhaust bend . I had a leak down there and was convinced that
it was the gasket or the rubber exhaust hose. What it turned out to be was a crack
in the cast iron exhaust. Do you have to take out the engine to get to yours? Mine
is quite easy to get to and remove. If you take out the saildrive I wouldn`t re-use the
rubber ring though.
Regards, Phil
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Rustyknight
Well-known member
I've had a Volvo saildrive for 11 years now, and replaced the seal last winter. From new, the recommendation was to replace the seal after 7 years, but this has since been extended to 9 years.
In that time the only cause for concern was when motor-sailing down the Alderney race and fouling a pot marker....... from 11k over the ground to zero in the space of a few seconds, and all the shock being taken by the engine mounts. Luckily they held, as did the seal.
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In that time the only cause for concern was when motor-sailing down the Alderney race and fouling a pot marker....... from 11k over the ground to zero in the space of a few seconds, and all the shock being taken by the engine mounts. Luckily they held, as did the seal.
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richardandtracy
New member
What better recommendation for their integrity can you get?
Regards
Richard.
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Regards
Richard.
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Dipper
Well-known member
I changed my Volvo seal (dreadfully expensive part) myself when it was about 11 years old. It wasn’t leaking or damaged but I just felt that I ought to – primarily for insurance purposes. After removal, I cut through the old one out of interest. Apart from very minor crazing on the rubber surface it appeared perfect and was constructed in a similar way to a fan belt with layers of ‘canvas’ type material between layers of rubber. One supplier of these told me that the only seal they had ever heard fail was a new one that the owner had replaced himself. To aid fitting, the owner had lubricated it and it had slipped out of the ring as a result of the lubrication!
PBO had an excellent illustrated article about 5 years ago on how to change the seal yourself. If you want to know how old your seal is, it should have the date of manufacture on it.
Rustyknight mentioned engine mounts. To my mind, apart from any other problems, it is important to make sure these are in good condition otherwise excessive engine and saildrive leg movement will put additional stress on the seal possibly resulting in premature failure. The rubber part of the mounts can go soft without showing obvious signs and on the Volvo there are only three mounts with the saildrive configuration.
The outer rubber seal on the Volvo is designed to streamline the hole and prevent debris getting up into the gap. It will have only a minimal effect on water ingress if the main seal goes. I have seen some boats where the owner has tried to seal this off completely and make it watertight but that is not its function and since it is a loose fit around the leg, that won’t work anyway.
On the Volvo, the saildrive and seal are mounted on a raised glassfibre moulding which is itself glassed into the hull. This means that the actual leak (if any) would not be as deep as first appears from the outside and the seal may possibly be near or just above sea level on some boats – although not much comfort if your boat is pitching and rolling about in a storm!
Overall, after many years of ownership, I am happy with the arrangement. At least there is no chance of ripping a P bracket out through the bottom of the hull if the propeller tangles with anything and as has already been mentioned, the saildrive is nicely tucked behind the keel for protection (fin keelers only!).
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PBO had an excellent illustrated article about 5 years ago on how to change the seal yourself. If you want to know how old your seal is, it should have the date of manufacture on it.
Rustyknight mentioned engine mounts. To my mind, apart from any other problems, it is important to make sure these are in good condition otherwise excessive engine and saildrive leg movement will put additional stress on the seal possibly resulting in premature failure. The rubber part of the mounts can go soft without showing obvious signs and on the Volvo there are only three mounts with the saildrive configuration.
The outer rubber seal on the Volvo is designed to streamline the hole and prevent debris getting up into the gap. It will have only a minimal effect on water ingress if the main seal goes. I have seen some boats where the owner has tried to seal this off completely and make it watertight but that is not its function and since it is a loose fit around the leg, that won’t work anyway.
On the Volvo, the saildrive and seal are mounted on a raised glassfibre moulding which is itself glassed into the hull. This means that the actual leak (if any) would not be as deep as first appears from the outside and the seal may possibly be near or just above sea level on some boats – although not much comfort if your boat is pitching and rolling about in a storm!
Overall, after many years of ownership, I am happy with the arrangement. At least there is no chance of ripping a P bracket out through the bottom of the hull if the propeller tangles with anything and as has already been mentioned, the saildrive is nicely tucked behind the keel for protection (fin keelers only!).
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