Hi guys, having problems with a leak on my boat, finally tracked it gown to the seal on the prop shaft. it was dripping at about 100 drops a minute which over a few days could be around 3 litres in the bilge underneath the engine. Anyway I noticed the knob on top of the seal and turned it clockwise, dripping was drastically reduced. I'm new to diesel engines so don't really know anything about them. So what's with this knob? Is it to restrict the dripping? How far can you turn it. I understand that you should have some drops, say 4 a minute to help cool down the seals when the engine runs. Anybody with similar setup?

Did check, is there enough grease. Perhaps time to remove the old one and top up.

Thanks chariot, it's really the function of the knob that I really want to know about.

That's an old greaser! If that is in an awkward spot it would have a standard grease nipple thread. It's easy to screw in a hose fitting and add some hose and install a cheap grease gun permanently in an easily accessible position. Occasionally as you leave the boat give the handle a pump.

Hi, yes if it's the type of old greaser I know, the "knob" is hollow, undo it all the way and pull it off. You then fill it full of grease and screw it back on. Every turn or so of the knob will then force grease into the shaft/bushings.

Similar to this set up: www.harfington.com/products/p-1315016?variant=43481862996217&utm_source=google&utm_medium=cpc&utm_campaign=Google%20Shopping&stkn=f8e35277684b&utm_source=google&utm_medium=cpc&gad_source=1&gclid=CjwKCAjwmYCzBhA6EiwAxFwfgKkFA-NGnyaFIbiv2zcSvdOS3nwXT24eDdzz5x1o1cv9SNTCb78cyBoCtUMQAvD_BwE

Any recommendations for grease?

Got that similar fitting on the snapper boat.
I use good quality trailer axle grease.
just keep it topped up and turn or two after every use.
If leaving the boat for a bit I force grease into the fitting just by finger pressure.
That usually stops the drip completely.

If a real continuing problem you might want to replace the lagging in the stuffing box.
There is a trick to that though.

Use marine grease, I know it's sounds odd but it's water proof unlike general purpose grease that breaks down in water

Like Woko said!

Marine grease, what brand, we are not the abc

Marine grease, what brand, we are not the abc

These articles are obviously excellent. Grease type depends on what the gland packing is - do you know if its a flax type needing tallow lubricant or ptfe type needing ptfe lubricant?
coxeng.co.uk/stern-gear/stern-glands/
bearsmarinedevelopments.com.au/Stern_Glands.php

This indicates Morris grease
www.asap-supplies.com/drivetrain/gland-packing-removal-tools/gland-packing
shop.tnorrismarine.co.uk/products/gland-packing

as per here.
shop.tnorrismarine.co.uk/products/morris-k99-grease

Guess you can search for an equivalent local product - maybe this one? I haven't had experience of either - trust Woko will respond
www.mxstore.com.au/p/Belray-Waterproof-Grease-16oz-Tub/99540TB16W

I use Penrite marine grease. I also have a container underneath the gland to collect the bit of grease and save on cleaning

Any boat trailer bearing grease will do. The excess usually ends up in the stern tube. The water pressure in the tube probably pushes the grease back against the packing.

Thanks guys. I have no idea what the packing is and doubt whether the previous owner would know either. the engine is a 2 year old Vetus 16hp and by the look of the service book it has not been serviced. Thats next on my list and I will get the mechanic to advise on the shaft set up. I will get some Penrite. I have been advised to run the engine while I turn the grease knob so as to get some grease on the shaft as well. Now I look back to my previous boats 8hp 2 stroke Yamaha with some fondness.

The vetus will be fine, I run two of them and am thinking a repower in another boat to Vetus

Select to expand quote

neilmac01 said..
Thanks guys. I have no idea what the packing is and doubt whether the previous owner would know either. the engine is a 2 year old Vetus 16hp and by the look of the service book it has not been serviced. Thats next on my list and I will get the mechanic to advise on the shaft set up. I will get some Penrite. I have been advised to run the engine while I turn the grease knob so as to get some grease on the shaft as well. Now I look back to my previous boats 8hp 2 stroke Yamaha with some fondness.

Re gland packing, R13s link gives good detail of various size & material available. Generally speaking the packing in a ring formed around the shaft, inside the gland nut can be compressed by tightening the nut which intern expands the packing and creates a seal. This seal requires lubricant and cooling, water provides both functions. It's a balancing act to minimise water ingress ( dripping) and over heating. Again generally speaking the grease is there to cause a drip free seal when not in use. There are modern dripless arrangements available but imho aren't worth the bother