Sterngland Question

[pissativlypossed]

Have noticed an intermittent whistle from what I believe is the water cooled stern gland on my boat, it is only at low rpm as we manouver in and out of the marina, there is no vibration and it stops within seconds. The water is flowing through the bearing and it is running cold.We experienced a similar problem last year which stopped as abrubtly as it started.
There is an alan screw on the top of the bearing, I have removed this for inspection and there is a trace of grease on the end of the alan screw. The question is, is there any maintenance to be done and can I/and should I top up the grease?

 

[essexboy]

Is it a Packless / Leakfree type or a dribbler ?

 

[pissativlypossed]

I believe it is neither, there is no way to pack it that I can see, and it is not the "deep sea" type that allows the odd drip.
It is fed from pipes of the raw water pump.

 

[eyehavit]

[ QUOTE ]
There is an alan screw on the top of the bearing, I have removed this for inspection and there is a trace of grease on the end of the alan screw. The question is, is there any maintenance to be done and can I/and should I top up the grease?


[/ QUOTE ]
First check that the alan screw hole does/does not pass through the bearing. If it does not, then the grease was placed there by whoever installed the alan screw so it does nothing other than help with removing the screw. If it does pass through the bearing, then the water cooled bearing is choked with grease which is preventing lubricating water from properly servicing the bearing.
My preference is to avoid the use of grease altogether when the forward bearing is water cooled. On one hand, grease may be ok for reducing friction, but on the other, it is a lousy heat conductor and if it is used in excess can choke off cooling water. Modern non-metallic hydro-dynamic bearings that are designed to rely on water lubrication do better without grease.