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.

[sgharford]

I have same stuffing box (one big nut followed by smaller jam nut) on both my rudders and prop shafts, it's as Blaine described - the packing is in the big nut - I have 4 rings in mine. If you suspect it may be replacement, you can figure out the packing size by measuring the threaded diameter the big nut screws onto and subtract the diameter of the shaft. Divide by 2 and round DOWN (not up) to the nearest 16th fraction to get your packing size. You really should check, I too was supposedly 3/8" and I ordered and precut all the expensive gore packing ahead of time only to find out actual packing size is 3/16" (not 1/4" - it would not fit no matter how hard I tried). My experience, you cannot squish packing and it will not fit if even off by 1/16th of inch, no matter how hard you try (and I have tried!). Any extra slop will easily be taken up one you compress packing rings. You get the old out but unscrewing the big nut and pushing all the way towards transmission shaft coupling to give most amount of room to work. Take small flat head screw driver and work/feel your way around until you find the seam of the first ring. Push screw driver into seam and pry out the first ring. Repeat for however many rings you have. When done, ideal if you have water hose and can spray inside packing nut and really try to clean it out before inserting new packing. The new packing should go in fairly easily if sized right and the gland is clean. Get as many rings in as you can, leaving enough threaded area on nut to grab stuffing box. The packing will compress a fair amount when adjusting. I too used Gore packing on props and actually replaced packing while still in the water. After initial adjustment and to get to right drip, I left boat tied to dock and put in forward at idle to make sure all was good. If you tighten gore too much it leaks like sieve and is garbage and you have to start all over with new packing, so take your time. I had same experience, it stopped dripping all together after about 10 minutes of use. I felt mine after cruising on first few ocassions with no drip and it was not hot, so assumed all OK. I had read that gore would stop dripping in allot cases so as long as it was cool to touch OK with me. Have about 150 hours on them on still OK. There's about 8 hours of 'learned the hard way" experience in above, it's pretty solid advice to at least check the actual packing size (and round down) with a set of calipers to get started.

[Beckytek]

That small hose connection looks completely useless to me. I can't see where it provides any cooling as it opens to seawater. To provide any cooling it would have to be up near the packing flange. I would check to see where the other end of that hose goes. Maybe it is an inlet for seawater to enter. For what reason I couldn't say. Good luck

[lake of the woods]

Brico,

My comments are a bit long winded and I apologize if you know most of this already. It was not my intention to treat you as not knowing anything. There may be other HOF members that are interested in this thread who may be less knowledgeable and benefit from my verbosity.

I repacked my main shafts and rudders last spring and can add to the good advice provided by sgharford. Both my main shaft logs and rudder logs are the same as your rudder logs, so my comments only apply to them. I am not familiar with your main shaft log set up.

Question: I assume from your two photos that you do not have any significant water leakage from your rudders or main shaft logs. If that is not accurate then you could be leaking from the two plates that sandwich the fiberglass hull on the rudder logs. That was one of my problems. Unfortunately I thought it was just my rudder log packing that was leaking. When I splashed the boat the water started coming in immediately and I had to get the yard to lift and move the boat and then fix that leak. An expensive lesson ($1000) I hope others can avoid.

Also if you have your "hatteras manual" (mine is a blue binder with about 100 pages) in there should be a "blueprint" page(s) that clearly depicts the rudder and main shaft log composition as well as the size of the packing material and how many layers you will need. That will help if your logs are original and have not been changed with something different.

I had a terrible time removing the old packing which appeared to be original (25 years old). It was as hard as steel and took two days to remove. The screwdriver method sgharford mentioned may work if your packing is still pliable. If it is not I would suggest you try to find some "dental pick" type of instruments along with a good pair of vice grips to help remove the packing. Prior to trying this I broke two "corkscrew" packing extractors trying to extract the packing. The heavy duty dental picks and vice grips worked the best for me. A small mirror or (if you have one) a video camera inspection tool can help you in finding the ends of the packing which is the best place to grab the packing for extraction.

Reinstalling the packing went easy. I used the less expensive "Western Pacific PTFE packing flax" and covered all sides liberally with the "packing grease". I cut the packing on a 45 degree angle so there was a bit of overlap (about ¼”) for every layer of packing. You should also stager the packing flax joints at 12 o’clock, 3 o’clock, 6 o’clock, and 9 o’clock.

When you tighten up the bolts on the flange be careful!! DO NOT OVER TIGHTEN. If you do it could cause the main shaft logs to overheat. Once the flax packing is "squished together" it will not expand back if you tightened them too much and then try to loosen them off. It is far easier to tighten the nuts just a bit. How tight should you tighten them? Until you start feeling any resistance from the packing (use a socket wrench). Stop! Then when the boat is splashed check for leaks and tighten them just enough to see about 2 drips a minute. My rudder and main logs did not drip at all even with minimum tightening. This may be because of the flax packing grease providing a bit of a seal. After running the mains and using the rudders for an hour or so check again for leaks and tighten if necessary. Check the logs every time you splash the boat or regularly if it is sitting in the water for months.
Good luck
Mark
Lake of the Woods
1989 40 DC

[brico]

That small hose connection looks completely useless to me. I can't see where it provides any cooling as it opens to seawater. To provide any cooling it would have to be up near the packing flange. I would check to see where the other end of that hose goes. Maybe it is an inlet for seawater to enter. For what reason I couldn't say. Good luck

The hose originates from the first elbow on the raw water discharge line, so it is definitely to supply the water into that thing.

I'll check with the Sam's Marine to see if they know more. I have the feeling this is original fitting. the manual says 3/8" packing but looking at some responses, I believe it will be less than that, perhaps 3/16' instead.

I definitely need to clean the stuffing box from all of the oxidation buildup and apply some Vaseline. It keeps it clean and protects from oxidation.

[jim rosenthal]

If you can get all that oxidatiuon off the bronze parts (a huge job in itself) try Corrosion-X. Works well in those kinds of applications, and respray it a few times a year.

The corkscrew packing extractors are worthless. They last about 0.5 secs each.

[SEVEN]

Spray down the green metal with vinegar. It des loves the green.

[SEVEN]

Desolves. Damn spell check.

[Maynard Rupp]

Our original book from Hatteras said our shaft packing was 1/2". I too bought Goretex. When I got the packing out it was #/8"/ I tried to make the 1/2" work also. It made a very hot shaft. I re-did it with 3/8" Gortex and, after 4 years it works fine and almost doesn't drip.

[Blaine Thorpe]

That is the same thing I had on the 36C. It was a pain to get the packing out and back in. I used some Harbor Freight seal picks to get it out. I remember using a cross section of PVC pipe to close to the same OD as the shaft help push it back in.

The second time I had the coupling off so it was a lot easier.

I don't think I would want to try this one in the water.

[Blaine Thorpe]

You really should check, I too was supposedly 3/8" and I ordered and precut all the expensive gore packing ahead of time only to find out actual packing size is 3/16" (not 1/4" - it would not fit no matter how hard I tried).

If I remember correctly, the inside diameter where the packing fits is actually larger than the ID of the threaded section. That what makes it hard to get the correct size installed.

[Beckytek]

I used 3 inch deck screws with phillips head and put them in as far as I could. Put 3 in at 120 degrees apart. Then I took a claw hammer and extracted the packing a little at a time. The hammer gives you a lot of leverage. I bought one of those extractors and it would not bite into the packing at all, useless.

[drburke]

I used 3 inch deck screws with phillips head and put them in as far as I could. Put 3 in at 120 degrees apart. Then I took a claw hammer and extracted the packing a little at a time. The hammer gives you a lot of leverage. I bought one of those extractors and it would not bite into the packing at all, useless.

Great idea!

DAN

[thoward]

I have used the Gore GFO with good success.

[Dreamboat]

I used 3 inch deck screws with phillips head and put them in as far as I could. Put 3 in at 120 degrees apart. Then I took a claw hammer and extracted the packing a little at a time. The hammer gives you a lot of leverage. I bought one of those extractors and it would not bite into the packing at all, useless.

That was an excellent tip. I just removed the packing on my boat with that method and it worked very slick. I found you can do it with one screw only. Just screw it in 1/2" to grab the first ring and pull and repeat for the rest of the rings.

Now I have a couple of questions for the experts. I'm replacing the old stuffing with GFO. I pulled out 4 rings of the old stuff. The GFO website says to use up to 3 rings of their material.

What has everyone done in the past 3 or 4?

One problem I just found is that I was short shipped the GFO material and can only get 7 rings out of the package content, so will 3 rings per side be sufficient?

How do you ensure the shaft and stuffing box is nice and clean? Can't get a finger in there to feel around for burrs or dirt.

As usual, thanks in advance?

[Boatsb]

That was an excellent tip. I just removed the packing on my boat with that method and it worked very slick. I found you can do it with one screw only. Just screw it in 1/2" to grab the first ring and pull and repeat for the rest of the rings.

Now I have a couple of questions for the experts. I'm replacing the old stuffing with GFO. I pulled out 4 rings of the old stuff. The GFO website says to use up to 3 rings of their material.

What has everyone done in the past 3 or 4?

One problem I just found is that I was short shipped the GFO material and can only get 7 rings out of the package content, so will 3 rings per side be sufficient?

How do you ensure the shaft and stuffing box is nice and clean? Can't get a finger in there to feel around for burrs or dirt.

As usual, thanks in advance?

I usually pull the whole assembly and take it to the bench. Clear any threads that are bungged and re assemble with some grease. The hose and clamp get changed too while I'm at it.

[SEVEN]

Use s thin screw driver and a thin rag to run all around the inside of the glan. 3 on each works just fine, just remember to off set each of the rings of packing. One splice on top one on the side and the final on on the bottom.

[hcalmar]

I have the same boat, same stuffing box on shaft and rudder. Same experience re the prints in the manual which says our 37 packing to be 3/8 inch. Had to throw it out. The shafts were repacked with 1/4" packing. The hose goes to the recessed cutlass bearing. In the past I have forgotten about that and sent a lot of antifreeze on the ground when winterizing!

[Beckytek]

Learn something everyday. Didn't realise you had a cutless bearing in the same housing as the stuffing box. Now I see the reason for the cooling water.

[Glory]

When repacking, I always do this in the water, I add molly grease, molly resists water wash out, between each ring of packing. I have found this to require an adjustment about every 200 hours.

When using the method the first time I only tightened the straddle nuts slightly snug. And that works fine. It has been close to a 1,000 since the last repack.

JM