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CSY Man · 22-06-2008, 14:35

Boat on the hard and plenty of work to do on this 30 year old lady.

Changed the cutless bearing, nice and snug now.
Also repacked the stuffing box with GFI packing and teflon lube. Tightened the stuffing box untill I could feel a difference in resistance turning the shaft with the zink. (Makes sense?)

Obviously I can't fine tune the stuffing box untill the boat is in the drink and I adjust the box using the no-drip method and feeling for heat buildup if too tight.

Have used the same adjustment for over 5 years, never touched the thing..Good stuff that GFI..Virtually maintenance free, but being so long ago I adjusted, wondering if there is a rule of thumb for adjusting while on the hard???

Inthewind · 22-06-2008, 17:10

After repacking and tightening many stuffing boxes throughout the years you sort of get a feel for it. You don't want it too loose, yet you don't want it too tight either, sort of in between if you know what I mean. After you get splashed in, you just want to keep an eye on it for awhile until you are confident that it is right. Stuffing boxes are always something that I am keeping my eye on and adjust when needed. New packing material should last along time before furthur adjustments are required once it is adjusted right.

CSY Man · 22-06-2008, 17:13

Agree on all of the above...So what is the answer to my question?

Should you be able to hand-turn the shaft with your hand on the shaft, not the prop...?

Inthewind · 22-06-2008, 17:18

Yes, you should be able to turn the shaft by hand.

Therapy · 22-06-2008, 17:24

That depends more on your tranny does it not?
One hand or two?
Enough friction to slow the shaft would burn it up I would think.
There is no magic, and don't tighten it till it gets good and wet either.

Inthewind · 22-06-2008, 17:56

I am assuming that CSY Man has a Borg Warner behind his perkins. Borg Warner transmissions are able to turn by hand. I have yet to see a tranny that would not turn freely while in neutral,but I am sure they exist.

CSY Man · 22-06-2008, 20:17

Quote:

I am assuming that CSY Man has a Borg Warner behind his perkins.

Well, it is a Hurst something. It turns quite freely when in Neutral...

The reason for this thread is that I did not turn the shaft by hand before I tore into the stuffing box, nor did I count the turns loosening the stuffing box..Should have done that, could have done that, but forgot...

Not really critical, but thought I ask some of the old salts for their hard earned advise anyway.

Roy M · 22-06-2008, 21:02

Okay, here is a really simple solution. Let's assume the shaft is turning and it's been tightened so that it still leaks. It's supposed to, otherwise the friction does bad things. As long as the shaft turns under power, let it drip once every couple seconds. Put your hand on the shaft coupling. It can be warm, but not hot enough to hurt you. That won't hurt the shaft. Now, put the engine in idle and give the shaft a couple minutes to cool down, and most importantly, allow the wax surrounding the flax or teflon packing to seize up. Properly tightened, the shaft drips will stop, and will return when the shaft friction builds up. Now, for the really tough part, accepting the fact that shaft logs are dynamic. That means you get to fiddle with them every so often. Properly done, they are accessible, the lock nut hasn't been tightened to the point that you need a couple of wrenches and four hands to loosen it. Before leaving the boat, make sure it has stopped dripping. If not, loosen the lock nut, give the packing nut a small turn until it stops leaking, then hand tighten the lock nut. Eventually the packing wears away and you have to replace it. That requires an extractor, looking sort of like a corkscrew, FOR THE SIZE PACKING you use. Don't know for sure? Slide the packing nut completely off the shaft, disregard the seawater pouring in, and measure the gap between the inside diameter of the packing nut and the edge of the shaft. Slam the packing nut back on the shaft log and tighten it until the water stops coming in. Go to the marine store and buy a package of shaft packing. Get one size above and below, as well, if you aren't sure (it's not too expensive) Now, wrap the packing around the shaft IN THE DIRECTION THAT THE SHAFT TURNS NORMALLY (that's what the old salts taught me, but it still doesn't make any sense). Slice this roll of packing in the axis of the shaft. Save three complete rings, toss the rest. Again, open the packing nut and slide it out of the way. Pull out the old packing with the extractor, slip the three rings on the shaft and ease them down into the collar of the packing nut, rotating the sliced part so it doesn't line up with another slice, then reassemble the packing nut to the shaft log. Tighten down, put the engine in gear and let it wear in for a bit. Keep testing the temperature with your hand. Go out and buy a spare pack of packing for next time and put the extractor with it. You just saved yourself a bunch of bucks. I'll add some pics in a couple of days.

**Alan Wheeler** · 22-06-2008, 23:31

Quote:

Properly tightened, the shaft drips will stop, and will return when the shaft friction builds up.

Ummm, Roy.... you sure you got that right??

Roy M · 23-06-2008, 14:49

I guess I wasn't too clear. When the shaft has cooled down, tighten the packing nut with your hands until it JUST stops dripping. Run the engine in forward for a couple minutes to check that it starts dripping ENOUGH to cool the packing nut and the shaft at the packing interface. Then shut it down again after use, check the packing nut, tighten ever so lightly until the dripping stops, tighten the lock nut and have a beer. The idea is that it is a dynamic operation, requiring fiddling. If it's too much for the owner, they can invest a lot of money on a so-called "dripless" shaft log. I was able to install mine in a spot where it could get easy access and regular attention. Some boats aren't built that way. If there is a hell, it will have a special corner for the designers and builders who make stuff that can't be serviced by mere mortals. And they get to spend eternity standing on their heads performing maintenance to the holding tanks of Hades.

slomotion · 23-06-2008, 15:40

Having repacked several stuffing boxes - all of them on the hard - I can safely say that ......... well, dunno. Tighten it until it 'feels' not loose but not too tight, put it in the water and see what happens, start engine, etc., adjust accordingly.

Hope this helps.

Next boat will have a dripless shaft.

CSY Man · 23-06-2008, 15:50

Yeah, thanks that was all good info and should go in the Study Hall for adjusting stuffing boxes.

The stuff I am using, Virtually Dripless Packing has been so good that I forgot how to...I could probably leave it alone another few years, but this is preventive maintenance.