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Post by ianqv on Aug 17, 2016 6:17:11 GMT
Hi All,
I remember reading on the fitting instructions of my last Volvo stern seal - "Grease every 50 hours"
Another good way to get the grease into the seal is to put some on your finger and smear a little around the area where the shaft and the seal meet.
Then tart the engine and give it a couple of bursts astern.
Note: you don't want to put loads and loads of grease on. Also, wipe off the old grease with a soft tissue prior to putting new grease on.
Regards
Ian
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Post by minnewaska on Aug 18, 2016 11:03:41 GMT
Yes, the PSS seal is more expensive. I priced the Volvo seal at about $150 for our shaft, while the PSS was $330. The complete maintenance kit on the PSS is about $110, which they recommend every 6 years. Of course, you have to replace the entire Volvo seal, although, the breakeven is still a long, long way out. If you're into greasing your Volvo seal regularly and not worried about scoring your shaft and replacing it someday, the Volvo seal is a less expensive route. Personally, I found just burping the thing to be a serious pain on a 35mm shaft, let alone greasing it (read all the necessary tips and tricks for greasing). As I've said, the simple fact that it requires grease, because it is rubbing on the shaft, is the deal breaker for me. Call the added expense, shaft replacement insurance.  |
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Post by MalcolmP on Aug 18, 2016 16:58:01 GMT
Don't think this has been mentioned in this now very long thread, but a couple of weeks ago after a mid season haul out - I forgot to burp the Volvo seal (which I had replaced last year) remembered after about 10 hours running - no drips - I do ensure it is greased - but the shaft and the rubber were running quite hot - could just about keep my hand on it... after burping the temperature dropped and has remained cool and so far no drips still, so think I got away with it...
So the water lubrication must also act as a heat sink to the sea
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Post by On y va on Aug 18, 2016 17:17:21 GMT
Hi All, I remember reading on the fitting instructions of my last Volvo stern seal - "Grease every 50 hours" Another good way to get the grease into the seal is to put some on your finger and smear a little around the area where the shaft and the seal meet. Then tart the engine and give it a couple of bursts astern. Note: you don't want to put loads and loads of grease on. Also, wipe off the old grease with a soft tissue prior to putting new grease on. Regards Ian Please DO NOT ATTEMPT THIS AT HOME what Ian is just suggesting here. It is plainly dangerous to run the engine in gear with one putting grease on the shaft. I am sure you know what you are/were doing Ian, but this should not be practised in general and certainly not promoted on a forum. Just apply some grease on a finger and turn the shaft by hand with the other hand and push grease around the seal top/shaft with the other. NEVER with an engine in gear. Furthermore and again: the Volvo seal is WATER LUBRICATED and cooled as Malcolm found out in practise. Hence it is important to ALWAYS burp the seal after launching. It these tiny rubber lips burn up, it can potentially sink your boat. I know some people here didn´t bother with burping and are even more or less proud of it, but it is plain luck they didn´t damage the seal. That little bit of grease is just to ensure the outer seal cannot run dry and rip to pieces when the shaft start turning, plus it prevents build up of a calcium/salt film in that area, which can also damage the lip seals. The grease is not for general lubrication purposes of the Volvo seal, hence you use a very small amount. |
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Post by ianqv on Aug 19, 2016 6:05:17 GMT
Hi All
Apologies if my post was misleading.
But at NO point did I say apply grease with the engine running.
To quote my post (minus the spelling mistake)....
IT CLEARLY SAYS: put some grease on your finger and smear a little around the area where the shaft and the seal meet.
Then start the engine and give it a couple of bursts astern.
Best Regards
Ian
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Post by On y va on Aug 19, 2016 16:04:01 GMT
Ok, I must have come to that conclusion somehow (or the red wine did it for me!  ). I was already quite surprised, as you always seem to know pretty well what you are doing. Thanks for putting that straight Ian! |
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Post by Mistroma on Aug 19, 2016 21:07:50 GMT
Penny might have finally dropped about the reason for the change in behaviour of my Volvo seal after renewing it.
I examined the old and new seals to check location of the lip seals. These are well inside the unit and I modified my usual practice of greasing just inside the seal. I knew that 1ry lube was via water but when Volvo said to grease I assumed they meant the lip seals. However, the instructions only say to put in grease and I imagine they'd specify a distance if it was meant to reach the gap between the lip seals.
I noticed that the seal needs to be burped frequently this year but the old one was almost always fine. I usually spotted it after brisk sails when well heeled and thought air must be getting forced underneath as we bashed through waves.
However, this never really made much sense. It now seems much more likely that suction opens the seals when sailing fast and air gets in from inside the boat. The seals are designed to resist pressure from incoming water which pushes the seal against the shaft.
I'll go back to putting the grease just inside the front face and monitor the situation to see if the need to burp is reduced.
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Post by vasko on Aug 19, 2016 23:48:23 GMT
Penny might have finally dropped about the reason for the change in behaviour of my Volvo seal after renewing it. I examined the old and new seals to check location of the lip seals. These are well inside the unit and I modified my usual practice of greasing just inside the seal. I knew that 1ry lube was via water but when Volvo said to grease I assumed they meant the lip seals. However, the instructions only say to put in grease and I imagine they'd specify a distance if it was meant to reach the gap between the lip seals. I noticed that the seal needs to be burped frequently this year but the old one was almost always fine. I usually spotted it after brisk sails when well heeled and thought air must be getting forced underneath as we bashed through waves. However, this never really made much sense. It now seems much more likely that suction opens the seals when sailing fast and air gets in from inside the boat. The seals are designed to resist pressure from incoming water which pushes the seal against the shaft. I'll go back to putting the grease just inside the front face and monitor the situation to see if the need to burp is reduced. I have Eliche-Radice version and with a clear hose it was visible in high rpms how the water is sucked from the hose - hence I connected the hose to my raw water pump with diameter reduction to ensure enough water goes in the heat exchanger and also has another opening overboar for anti-siphon... Eliche-Radice also has a greasing opening making life easier... and also for who still do not know - Elice-Radice is the manufacturer of the Volvo seals, shaft and propellers - e.g. no compromise with the quality - just better quality for the money spent... |
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Post by Damir on Aug 20, 2016 17:56:42 GMT
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Post by ianqv on Aug 21, 2016 20:21:30 GMT
Ok, I must have come to that conclusion somehow (or the red wine did it for me! ). I was already quite surprised, as you always seem to know pretty well what you are doing. Thanks for putting that straight Ian! No problem Buddy.... it's reassuring that I'm not the only who posts whilst having a glass of the red stuff!!! |
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Post by sailbleu on Aug 23, 2016 7:04:50 GMT
Penny might have finally dropped about the reason for the change in behaviour of my Volvo seal after renewing it. I examined the old and new seals to check location of the lip seals. These are well inside the unit and I modified my usual practice of greasing just inside the seal. I knew that 1ry lube was via water but when Volvo said to grease I assumed they meant the lip seals. However, the instructions only say to put in grease and I imagine they'd specify a distance if it was meant to reach the gap between the lip seals. I noticed that the seal needs to be burped frequently this year but the old one was almost always fine. I usually spotted it after brisk sails when well heeled and thought air must be getting forced underneath as we bashed through waves. However, this never really made much sense. It now seems much more likely that suction opens the seals when sailing fast and air gets in from inside the boat. The seals are designed to resist pressure from incoming water which pushes the seal against the shaft. I'll go back to putting the grease just inside the front face and monitor the situation to see if the need to burp is reduced. As mentioned before I do not burpe the seal as often as I apparently should , not that I'm proud of it like some unfoundedly may suggest ( i guess red wine does different things to different people ) , but whenever I do there 's aways air in it. I always freewheele my prop , do alot of millage , meaning that my seal suffers , and it's been in there for ........is it 6 years ? Not a drop come through , so my practical experience about burping is somewhat controversial to what some ( self-proclamed ?) professionals tell me about that burping. No question about it , grease needs to go in , period . Perhaps someone could tell us what the purpose of water in the seal is ? Cooling ? Once the seal heats up , and friction does create heat , the water incapsuled in the between the two lips will heat up also . There's no circulation so there's no heat exchange . Water in or not , the seal heats up and will cool down for a brief moment when you burp it and cold water evacuates the hot water. Now what about burping in merky waters ? We all know what seawater ( salt & sand ) does to our raw water impeller , wouldn't the seal lips suffer more because of that ongoing circulation of abrassive water ? So do I objectively question the burping ? Yes , as stated above , years of so called neglect have not destroyed my seal . So am I inclined to call burping overrated ? Yes. Could I be wrong ? Yes But history has been on my side sofar. The thing is Mistroma , I was wondering if the freewheeling could have something to do with the air getting into the seal ? Just a thought. If that were to be the case , then prop in reverse whilst sailing would solve this issue. But as we had a topic once about freewheeling the prop an other professional convincingly assured us that freewheeling puts less pressure and wear on the gearbox than reverse mode does. Regards |
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Post by vasko on Aug 23, 2016 18:36:59 GMT
re:burping sailbleu looks right to be honest - in reality every time you put some RPM's the water from the seal is sucked by the prop and most likely air is filling the seal through the lips .. and when try to burp it you will always find air... e.g. seems very logical - for the greased lips to stop the air they should be really new and strong... sailbleu most likely your seal is old and the lips can prevent water to drip, but let the air in towards the propeller... some grease should also disappear towards the prop also if the assumption is correct - e.g. your seal is quite well greased ...
re: why burping - I was always told that it is for cooling.. and of course no mater how you think about it the heat exchange in the water is a lot better then in the air... e.g. having water in the seal will keep it cooler, but as described above in your case there is always only air .. may be just you seal in in state when it cannot stop air but can still stop water...
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davidj
Junior Member
Posts: 18 
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Post by davidj on Jul 12, 2017 18:37:39 GMT
Stuffing Box PRICE FROM £79.60 (1in shaft) Volvo Penta’s solution is what they call a ‘rubber stuffing box’. It’s simpler than its competitors, combining the rubber hose with a lip seal in one assembly, with no moving parts. It has an internal, water-lubricated bearing and lip seals which must be greased every 200 hours/once a year. It comes with a single, wide hose clip, secured with machine screws, to clamp on to the stern tube. After launch it must be ‘burped’ to remove air, as it does not have a pressurised water feed. Volvo Penta recommend it is not used for installations where flexible couplings are used. Read more at www.pbo.co.uk/gear/dripless-shaft-seals-pbo-buyers-guide-17357#BGG5F8KPTsE8K5do.99 |
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whuati
New Member
Posts: 3
Jeanneau Model: Sun Odyssey 45.2
Yacht Name: WHUATI
Home Port: Bristol
Country: Greece
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Post by whuati on Mar 29, 2018 15:27:17 GMT
Hi,
we replaced our Volvo seal in the water. This did require diving under the boat and pushing a rag in the shat tube then we only had half a cup of water enter the boat. Easy job bit don’t forget to remove the rag!
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). I was already quite surprised, as you always seem to know pretty well what you are doing. Thanks for putting that straight Ian!
