Dribbling stern gland

[Burrium]

I noticed this weekend (yes - after a cold but beautiful day out!) that there was a small amount of water in the bilge beneath the stern gland.

On investigation, there is a slight horizontal judder of the shaft when the engine is in neutral. This causes enough movement to create a small dribble from the gland.

With the engine in gear, the rotational movement is enough to remove the judder and no water leaks in. Hence the very small amount of water when I checked - we are not in neutral long.

Is this a portent of worse to come? Can anyone advise what might be causing the horizontal judder? Any advice on best way to reslove the problem?

Many thanks,


Dai.

 

[nimbusgb]

Worn cutlass bearing?

 

[earlybird]

The judder is a feature of most engines on tick-over, esp. if the tick-over speed is slightly low. Try increasing it a trifle if you think it is excessive. 800rpm is a reasonable figure, the handbook should give a guide.
You don't say what type of gland it is. It might just require greasing.

 

[sailorman]

/forums/images/graemlins/confused.gif

 

[Severnman]

Er not just greasing methinks - not the function of the grease! You may want to try nipping up the sterngland nut if you have a conventional stuffing box type. The horizontal judder would concern me. What condition are your engine mounts in - when did you last check alignment? As Nimbusgb says, you may want to look at your cutless bearing soon. 2 or 3 drips a minute from your conventional stuffing box is quite acceptable though.

 

[sailorman]

i dont have the problem /forums/images/graemlins/wink.gif

 

[matelot]

[ QUOTE ]

This causes enough movement to create a small dribble from the gland. Is this a portent of worse to come?

[/ QUOTE ]

Yes indeed. Shares a problem with half this forum. /forums/images/graemlins/laugh.gif

 

[tillergirl]

Lets take this apart:

On the outside of the boat you will have a stern bearing either a plain or cutlass bearing. This is not water tight using water as a lubricant. Your stern tube twix the culass or plain bearing and the stuffing box will have water in it. You really (I think) can only tell if the cutless or plain bearing is worn by slipping the boat and checking the amount of play. Water inside the boat is not an indicator of a worn cutlass.

As to the stuffing box, you don't say what sort but it sounds like you have the old fashioned sort where a water tight seal (or nearly) is maintained via graphite impregnated cord inside the housing. Such a bearing is lubricated either by grease or water. It certainly should be well greased if it is grease lubricated. Typically such a bearing is said to be correctly tightened if it drips say once a minute under way. Usually it would be dry while stationary with the engine in neutral but I wouldn't say that the end of the world is about to arrive from the odd drip in neutral. It can be adjusted by tightning the nut as has been said - or the two nuts as can be found on some. Don't overtighten and bind the shaft.

As to judder. Any diesel is going to transmit vibration along the shaft. Is that what you are seeing? If you have a 'modern' seal type of inner gland, it should not leak at all and the drip is something to tackle.

 

[Richard10002]

Couldnt have put it better myself!

 

[Burrium]

Thanks for this info (and to all others who responded).

As you suggest, the judder is purely a result of the diesel engine vibration - not massive and only a small movement.

I believe the gland is of the sealed type - I will double check. The boat is a Jeanneau SO35 (2003); engine is Volvo Penta 2030, if that helps shed any light on the matter!

Once again, thanks for all input.

Regards,

Dai.

 

[mickbond]

Hi I have a 2005 SO35 with a Volvo 2030 engine 100hrs. This thas a ZF gearbox not the Volvo one.
My gland is a Volvo Penta rubber sealed unit PN 828254.

After Launching last year I observed that it leaked slightly on tickover (slight vibration from the engine as you describe) but not when in gear or above tickover. I loaded the gland with a little grease Volvo PN 828250 and the leak stopped. It has been OK all season
since.

Regards

MIck

 

[Danny]

[ QUOTE ]
...but it sounds like you have the old fashioned sort where a water tight seal (or nearly) is maintained via graphite impregnated cord inside the housing. Such a bearing is lubricated <u>either by grease</u> or water.

[/ QUOTE ]Nice complete description but I'd nit-pick about the lubrication comment: the grease is there to waterproof the packing - not to lubricate. The lubrication is provided by the film of water between shaft and packing surface. That's why it's important (and annoying) with traditional glands to have the occasional drip of water come through the bearing.