Stern Gland

[CaptainBob]

People I bought my yacht from said the stern gland needed to be squeezed on re-entry into the water to re-fill it with water as it's a water lubricated stern gland. They said that as it was new/stiff (it's a relatively newly installed engine) it might even need to be done with some tool.

I know nothing of these things.

But, I just applied very little pressure to it (by finger and thumb, while afloat) to see what would happen, and immediately it began to trickle water out, into the bilge. Held it for a while and it KEPT trickling, so not a temporary thing. Not a very hard press at all really.

Is this normal?!!!??!

 

[Mudplugger]

If it is a Volvo Seal....Normal /forums/images/graemlins/smile.gif if not! /forums/images/graemlins/frown.gif

 

[noelex]

If you push the bellows back a PSS (one of the most popular types) seal will leak. This is normal. Can you photograph your shaft seal so we can identify it?

 

[MoodySabre]

If it is a Volvo shaft seal then read all about it here

 

[Danny]

If it's a Deep Sea Seal (picture) it's also normal.

 

[Scotty_Tradewind]

I've just fitted a new Vetus stern gland and cutlass bearing.
http://viewer.zmags.com/showmag.php?mid=hggds#/page180/

I'm a little concerned that although I applied the silicon grease supplied it all squeeks like mad. I've yet to replace a few more bits so when all connected, I'll put a hose into the engine water filter and start her up to see if when the water supply from the engine is running through it, it quietens down.

 

[CaptainBob]

Thanks for the replies.

Seems such a crazy idea to have something that pees water in when pressed a little! Surely it'll leak whenever there's vibration from the engine?! I'm going to run up the engine and watch very closely!

I'll take a photo and post it up when I get a mo.

Thanks again!

 

[vyv_cox]

I don't know the Vetus seal but mechanical types, with a carbon ring against a stainless steel one, will scream when run dry. It's not a good idea to run these unless the boat is in the water. With a forced feed it should be OK but even then there is the risk that water will just run out of the stern tube rather than lubricating the seal. I think I would wrap a bit of rag or something around the shaft at the stern tube to provide a bit of back pressure, but take it very steady.

 

[Danny]

If it's set up right there should be enough pressure between the bearing surfaces to prevent vibration being a problem. Check through any bumf that came with the boat - there may be a manual or installation guide for it.

 

[Chris_Robb]

[ QUOTE ]
I've just fitted a new Vetus stern gland and cutlass bearing.
http://viewer.zmags.com/showmag.php?mid=hggds#/page180/

I'm a little concerned that although I applied the silicon grease supplied it all squeeks like mad. I've yet to replace a few more bits so when all connected, I'll put a hose into the engine water filter and start her up to see if when the water supply from the engine is running through it, it quietens down.

[/ QUOTE ]

You must also spray water over the cutlas bearing - this is the bit probably making most of the noise on turning the propshaft.

 

[Scotty_Tradewind]

This is another type of water lubricated stern gland on the market.

http://www.tidesmarine.com/seriesone-shaft-seals.html

 

[MoodySabre]

[ QUOTE ]
Thanks for the replies.

Seems such a crazy idea to have something that pees water in when pressed a little! Surely it'll leak whenever there's vibration from the engine?! I'm going to run up the engine and watch very closely!

I'll take a photo and post it up when I get a mo.

Thanks again!

[/ QUOTE ]

The purpose of 'burping' the seal is to expel the air - it is water cooled and lubricated and if you do not burp it then it will overheat and wear and start leaking.

You should only need to burp it when launching or after drying out.

The ones with a water feed overcome this.

 

[Tranona]

This is a water lubricated and cooled system. Bearing surfaces designed to be water lubricated will make a noise if dry. Do not run without the water feed connected. The lip seals are only there to stop the water getting in the boat and are also kept cool by the water.

 

[Tranona]

If it is a Volvo seal - and it sounds very much like it, see Moodysabres link for picture and instructions, there is absolutely nothing to worry about. The "seal" is in fact a water lubricated rubber bearing similar to the cutless you will find in your P bracket, but with two lip seals to prevent water getting into the boat. You will need to grease the seals say every year with Volvo grease and "burp" to expell air from the stern tube after launching. This is as low a maintenance and idiot proof bit of kit you are likely to own!