Engine shaft packing question

[brico]

I will be hauling out for bottom paint, zincs etc, in May. At same time i'd like to renew my shaft gland packings. As per Hatteras owner's Manual on my 1980 37C engine shaft packing is 3/8" and rudder shaft is 1/2" . My engine shafts stuffing box has a big nut instead of two stud bolts for pushing and tightening the packing in. I also have a 3/8" raw water line hose leading onto the stuffing box for what I believe is the cooling.

My question is, how far do i tight the packing in? I've seen a comment in one of the posts to tighten it such that few drops of water drip every one minute while the shaft is turning. is that correct? Do I need that water dripping into the engine room if I have the cooling line plumbed into the stuffing box?

I'd like to keep my bilges dry.

What about rudder shaft stuffing box? This one has two bolts and obviously no cooling water connected, but the rate of turn on the rudder shafts is so little. Trust there is no need for the water to drip into lazarete as , again, i'd like to keep it dry.

Any comments / suggestions are welcome.

Petar

[SEVEN]

I tighten the nut as far in as it can go then back it off until it starts to drip. Then re-tighten about a 1/4 turn or until the drip stops. While underway please check the temperature of the shaft to make sure it's running cool. If it's hot you need to back it off. Good luck

[brico]

Thanks for the tip Seven,

Tightening as far as it goes by hand or using the big pipe wrench? The difference is significant.

Petar

[SEVEN]

You want to push the packing material up as far as you can using tools. Backing it off as far as you can keeps water cooling the shaft. You want to have as much room there as possible. Just back it off till it drips then tighten 1/4 turn or until the drip stops.

[drburke]

It matters what material you are using, basic flax or GoreTex, etc. so you should review the manufacturers instructions.

There were a lot of threads a few years back about people liking the GFO stuff.

DAN

[saltshaker]

Post a picture of what you have. Sounds like you have dripless shaft seals if there's a cooling line.

[sgharford]

I'd do what Jack said and post picture before running with advice to tighten as far as it will go and then back off. You will ruin GFO packing for good if you do this. I think it will even screw up regular flax packing. I've done both the rudder and prop shaft's on a few boats and following the packing manufacturer's instructions is the only advice you should take, just as previously stated. My two bits, flax packing with no drip is fine on rudders as they don't turn enough to generate any significant heat. I wouldn't go any tighter then just enough to stop the drip, this will give you some play in the packing a few years down the road to tighten again when a drip does begin. GFO on prop shafts the way to go, unless of course you have dripless stuffing box with no packing at all. To best of my knowledge the reason for the drip is to lubricate and carry away trapped air, which can happen when you go in reverse or are in snotty conditions. Without water as bearing of sorts between shaft and packing, things really heat up fast. You need the drip otherwise the packing will burn out and drip really bad with no other solution other then to repack all over again.

[Blaine Thorpe]

I had that same configuration on my 36C. One large nut with a jam nut behind it. The packing goes into the large nut. I have done it twice, once without removing them from the shaft and once when I was replacing the stern tube hoses. It was a real pain getting the old packing out and back in without removing them.

I used the Gore-Tex packing the last time and tightened them as described above. Didn't drip for the first two years without overheating. They started dripping on the third year and only required a little tightening.

[brico]

I do not think this is dripless shaft seal. I had PSS dripless haft seal on my sailboat and it was certainly different with that carbon ring that pushes against the Stainless Steel collar to seal the arrangement. This surely has some sort of packing in that big 2 3/4" nut (shaft is 1 3/4") but what is the function of the raw water hose I have no clue, unless, when the boat is moving and syphoning effect empties that space that the hose fills in when the engine is running...

attached are photos of the engine shaft stuffing box arrangement and my rudder stuffing box arrangement which is typical one with the two bolts pushing the flange that pushes the gland packing and sealing it.

has anyone seen this engine shaft stuffing box arrangement? is this original Hatteras, or maybe retrofitted?

[Maynard Rupp]

I have never seen one like that. I do notice that those hose clamps are not tight enough. Your ground wire has pulled up tight and is the only thing that is keeping rhe whole assembly from rotating.