Propeller Shaft Leak

[roadnsky]

Late model A4 in a '78 Ranger 30...
I have a leak on my propeller shaft that seems to be getting worse. It appears to be dripping where the collar bolts tighten on the shaft. Here is a picture. Anyone have a suggestion for stopping or slowing this leak down without pulling the boat out of the water?
Thanks,
Jerry

[marthur]

The collar bolts are known as a "stuffing box." They are supposed to drip just a little when the shaft is turning. They are also easily adjusted.

Have you tried adjusting the stuffing box?
Second, have you replaced the packing lately?

[s/v Dearbhail]

Looking at the picture, you can see the thinner lock nut, Loosen that, then turn the larger packing nut until the leak stops with the shaft NOT turning. It should leak a few drops a minute when the shaft is rotating.

You can also add more packing if needed. It looks like you have a lot of room to unthread the packing nut and slide it to the right. Some water will trickle in, but it's not bad.

[jhwelch]

Here's a little tip for those disadvantaged with poor access to their
stuffing box area---it's easier to loosen the packing nut and then rotate
the lock nut then the other way around. There's a lot more surface
area to grip on the packing nut. I have to access mine kneeling in
front of the engine, laying on top of the motor, and putting my head
between the back of the engine and under the gas take--thank goodness
I have long arms!

Another tip, tie a string to your wrench in case it slips out of your hands.

-jonathan

[roadnsky]

Thanks for all of the informational replies.

I just bought her a couple of months ago and have been spending my days getting her into shape. (Water pump, hoses, thermostat and housing, hot exhaust section)

marthur - Haven't tried adjusting yet. I was afraid I'd open up too much leaking. Not sure when it was last re-packed.

dearbhail - I got the same suggestion from West Marine. Right now the leak is a bit too much for me (about a drip every 10-12 sec) I'm gonna try the tightening first. If not, well another project for the punch list...

By the way jhwelch, I've learned the string-to-the-wrench trick the hard way.
Thanks again for the replies!
-jerry

[roadnsky]

Update...

Ok, I tried loosening the lock nut and turning the packing nut but could only lessen the leak to about a drip every 20 seconds.
So it's on to re-packing or adding to the stuffing.

Does anyone know what "size" the stuffing is?

I went to West Marine and there are various sizes and the Rep couldn't tell me which one would fit...

[julian hood]

Leak

If you are getting a drip every 20 seconds that should be about right. A little water coming out helps cool the shaft. Sometimes if you mess with it to much you just open another can of worms.

Julian

[roadnsky]

Thanks Julian.
I should have mentioned that the drip is with the shaft NOT turning (boat at rest). It's not bad, it's just a lot of water pooling after a few days.
I'll eventually re-pack the stuffing since I don't know when this was last done (if ever)

I'd still appreciate if anyone know what size that stuffing is...

[tenders]

Buy several sizes. Return whatever you don't use. Make sure you have some sort of a hook tool on hand to dig out the old flax from inside the nut. The water flow while you're doing this looks scarier than it is, but it's too much to allow you to take a leisurely trip with the old flax to the chandlery to get just the right size. Also, you may not be able to tell the right size from the crushed old flax anyway.

The right way to repack the flax is to use three concentric rings of flax with the cut joints offset 120 degrees from each other -- NOT with a single spiral of flax.

[jhwelch]

Over the course of time a propeller shaft will become scored, so you might
want to check that too, if you ever unscrew your packing nut and slide
it forwards to expose that section of the shaft.

Here is what my old shaft looked like last summer:

[rheaton]

Sir, the links below provide some good tips on stuffing box maintenance. You could find more via google. The book "Mechanical and Electrical Manual" by Nigel Caldor is also an excellent source of information about all boat systems.

Best of luck.

http://www.boatus.com/boattech/Casey/StuffingBox.htm

http://www.alohaowners.com/pages/projects/stuffing/stuffing_box.htm

[roadnsky]

tenders - good idea. Should have thought of that...
rheaton - thanks for the links
jhwelch - something else to "worry" about!

Good info from everyone. I love this resource!

[msmith10]

There is a material called "Drip Less Moldable Packing" sold by West and presumably others that is like a modeling clay and is meant to pack the stuffing box in place of flax packing. It's pricey but has good reviews. You'd still have to make sure you get all the old packing out before putting this stuff in. Use little picks (the "dental" hooks sold at various stores work well for this).

[roadnsky]

I also saw a "Teflon" material that the West Rep said is reputed not to leak, but the pessimist in me makes me tend to stick with tried and true methods and materials.
My slip neighbor told me the Teflon stuffing had a tendency towards the shaft running hotter.

Anyway, another project for the (not shrinking) punch list...

[blind navigator]

Packing material

I've had good luck with PTFE Flax packing by Western Pacific Trading (I'm pretty sure I got it at West Marine), and the three separate rings with the splits (carefully cut on a diagonal) staggered around the shaft. Smear a big finger full of Superlube Teflon grease (Edson sells it to squirt in their pedestal bearings-you may be able to find it locally) in the fitting before you screw it up and they'll last for several seasons. It really hard to be sure you've got all of the old packing out before you put the new stuff in, but it's worth the effort. You'll probably need 1/8th inch or 3/16th inch diameter packing.

Once it's stopped leaking (shaft not turning), it's about right if it drips once or twice a minute with the shaft turning.

As a safety measure put a stainless steel clamp around the shaft (to the right of the fitting in your photo) so if the engine coupling ever does let go, you won't loose the shaft and prop out of the stern tube.