Stuffing Box Leak - 2QM15

[Moondawg]

I checked on my sailboat yesterday to run the Yanmar 2QM15 after sitting for a few weeks after a freeze. The engine started up easily, and as I checked for leaks I noticed a drop of water, one drop every couple of seconds, coming from the stuffing box. I see that I need to replace the packing based on YT vids. My question is, how can it be done with the boat in the water?

20250305_122417.mp4

drive.google.com

 

[Davidasailor26]

It can be done. You’ll have some water come in while the stuffing is removed but it won’t be a catastrophic amount. Having said that it wouldn’t be my preference for a first time changing the packing without any practice.

 

[Davidasailor26]

Also, before replacing you could just try tightening it a bit. You could also give it some time to see if it swells up on its own as it gets wet again. If it’s not dropping at rest you’re not too far out of spec.

 

[Tally Ho]

You could try adding 1 ring of packing (and don’t remove the old packing) and see if that helps stop the leak. And as @Davidasailor26 said, try tightening the packing nut to see if that stops the drip while the shaft isn’t turning.

Greg

 

[jssailem]

If you attempt it, be certain you have fully functional bilge pump or two in place.
Maine sail has some guidance.

Re-Packing A Traditional Stuffing Box - Marine How To

The Stuffing Box (click any image to see a larger version) While digging around in some old boat parts boxes I found a stuffing box from an older sailboat. I though it would be a good time to rig it up

marinehowto.com

 

[Ralph Johnstone]

The engine started up easily, and as I checked for leaks I noticed a drop of water, one drop every couple of seconds, coming from the stuffing box.

How this goes depends on the age of the packing and its composition. If it's old crap, all of it will require replacement. Relatively new, maybe be able to get away with adding a ring, if there's any room.

If you are going to replace all of the packing, this will take several hours or more. In order to keep the incoming water under control and your sox dry while digging out the old packing, try this :

​

Once you have the incoming water stopped at the shaft log, you have all day to do the job with no water ingress except for a small amount when pressing the new packing into place.

Practice just getting the string into place ON and OFF to start with.

This is how I do mine in the water as I'm not about to do it on the hard where I'm paying $40.00/day. I stick to the stuff that really can't be done in the water.

 

[Moondawg]

How this goes depends on the age of the packing and its composition. If it's old crap, all of it will require replacement. Relatively new, maybe be able to get away with adding a ring, if there's any room.

If you are going to replace all of the packing, this will take several hours or more. In order to keep the incoming water under control and your sox dry while digging out the old packing, try this :

View attachment 230098
​

Once you have the incoming water stopped at the shaft log, you have all day to do the job with no water ingress except for a small amount when pressing the new packing into place.

Practice just getting the string into place ON and OFF to start with.

This is how I do mine in the water as I'm not about to do it on the hard where I'm paying $40.00/day. I stick to the stuff that really can't be done in the water.

Excellent!

 

[Claude L.-Auger]

Excellent!

This is also how I do it and doing the job is really almost waterproof. The only 2 times you will get water in is first when you unscrew the packing gland before you have had a chance to wrap and tighten the cotton strings and put the grease. As mentioned after that is done you have all the time in the world to remove the old packing and install the new one. The 2nd time for water intake is when you remove the cotton string before you have screwed back the packing gland. Your bilge pump should easily take car of that but it's a good idea to make sure with testing before. Good luck

 

[Moondawg]

How do I determine what size packing to buy?

 

[Ralph Johnstone]

How do I determine what size packing to buy?

Purely a guess here but from your boat length, I'll say you have a 1.000" dia. shaft. and will take either a 3/16" or 1/4".

Use only Western Pacific Trading teflon impregnated flax. Buy both 3/16" and 1/4" and return the one your don't use.

I can get 6+ years out of mine before it starts to get a little hard and leaks excessively.

 

[Ralph Johnstone]

Follow the post #5 link to the letter.