volvo shaft seal

[pathfinder]

Fitted one of these recently as part of an engine replacement.After motoring for hour it felt hot to touch although i had burped it earlier i did it again and found the water that spurted out was also hot,now i find that the temperture seems to rise and fall while motoring the stern tube and prop shaft are also affected this way.The shaft is 25mm and would have been spinning at about 1200rpm at the time.It does not seem to have had any ill effects on the seal but i'm still a bit concerned.Anybody know if this is normal is there a run in period? etc.

 

[Skyva_2]

No running in is necessary, and mine runs cool. Sounds as if water cannot get access to the seal from astern. You did grease it?

I have seen references to fitting a water feed to a Volvo seal to avoid the need for burping.

 

[chwarae]

My seal runs quite hot, I can hold my hand on it but would not like to keep my hand on it for a long time. Asked a number of other guys with same seal and it appears to be normal. One guy said his didn't but when he checked it he found his also ran warm. My shaft is 1 inch. I read somewhere that the cutless bearing holder doesn't need dedicated water feeders on 1 inch shafts but may do on greater diameter shafts. By water feeders I mean the horizontal wings with water inlet holes built in to some cutless bearings.
Harry.

 

[pathfinder]

yes I did grease it,when I burp it i get a good flow of warm water which is bearly tolerable to touch so it looks like water is getting to the seal

 

[SimonD]

Mine also runs hot and I need to burp it quite frequently, ie every day. I can't think how air is getting in, but it does. Mind you, seems to have no ill effect.

 

[misterg]

[ QUOTE ]
...The shaft is 25mm...

[/ QUOTE ]
and:
[ QUOTE ]
...warm water which is bearly tolerable to touch ...

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Are you *certain* it's a 25mm shaft, and you haven't got a 1" shaft running through a 25mm seal?

0.02p

Andy

 

[pathfinder]

definately 25mm,it seems other people have similar issues, I'm worried the rubber is not up to the heat and might fail suddenly.What puzzles me is why the heat isn't conducted away from the stern tube with all that seawater in contact with it, also its at least 2ft below the waterline no air getting in.
thanks for the replys.

 

[Malish]

Re the water temp - I would have though a key issue is the rate of water exchange - what did you have fitted prior to the Volvo - was it an ordinary stuffing box with greaser? if so then remaining grease in the stern tube may be restricting water exchange - even at the best of times with any length of stern tube the rate of exchange must be fairly small.

 

[pathfinder]

The original was a traditional stuffing box with greaser.When burping there is a good flow of water so I assumed I had got most of the old grease out but you could be right maybe just a small amount of remaining grease is enough to restrict heat exchange

 

[jerryat]

[ QUOTE ]
Re the water temp - I would have though a key issue is the rate of water exchange - what did you have fitted prior to the Volvo - was it an ordinary stuffing box with greaser? if so then remaining grease in the stern tube may be restricting water exchange - even at the best of times with any length of stern tube the rate of exchange must be fairly small.

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Yes, I think that's a likely problem. There was a guy on here a few weeks ago who had fitted the Volvo seal but slapped a lot of grease on the shaft before sliding it onto the shaft.

Clearly, the ridge of grease jammed up against the outer, supposedly water-cooled seal, prevented sufficient water reaching, lubricating and cooling the seal.

I've been using one of these for 24 years and have NEVER found the seal remotely warm even.