Replacing Stuffing Box Hose

[dkinzer]

I'm planning to re-pack the stuffing box on our 2007 H41AC some time next year when I can get it hauled out. While I'm at it, I should probably replace the hose, too. The hose is about 5-1/2" long and I measured the O.D. as 3" and O.D. of the snout at the aft end as 2.725". The hose O.D. seems reasonable but the snout diameter seems odd. I measured using vernier calipers that I keep on board.

Has anyone replaced the hose on theirs and, if so, what size and type of hose did you use (metric or Imperial)?



Also, there appears to be some discoloration (possibly even some build up) on the shaft right where it enters the gland. When repacking a stuffing box, has anyone found a wear groove or scoring on the shaft and, if so, how did you go about addressing it? I suppose that the hose could be shortened by a small amount to get the packing to ride on a different part of the shaft.

 

[Rick D]

If you are going to the trouble of replacing the hose, have you considered a dripless shaft seal? Perhaps on this site, you can find a copy of your manual which should have the measurements. Good luck!

 

[dkinzer]

I had been thinking of replacing the stuffing box with a dripless seal. However, after reading more about it and its failure modes, I decided that the stuffing box was easier to deal with if something goes wrong while underway, especially far from shore.

I do have a copy of the manual but I don't recall seeing specifications for the stuffing box. I'll go back and look again. Or, perhaps there's a different manual that I don't have.

 

[Ralph Johnstone]

When repacking a stuffing box, has anyone found a wear groove or scoring on the shaft

Is this the area on the shaft you're referring to :

If so, it's unlikely to be in the area of the packing. The packing rub area on the shaft should have a mirror polish like this :

However, you do have a problem with your shaft position/gland position to cause the gland nut to rub on the shaft, if that is what we're seeing in your photo.

What was your last shaft alignment like ? There is one, I hope.

 

[Ralph Johnstone]

I had been thinking of replacing the stuffing box with a dripless seal. However, after reading more about it and its failure modes, I decided that the stuffing box was easier to deal with if something goes wrong while underway, especially far from shore.

Excellent decision. Especially when you realize that according most manufacturer's instructions, the dripless seal's bellows should be replaced every 7-8 years.

How hard could that be ?

 

[dkinzer]

Is this the area on the shaft you're referring to

It is. Your comment about alignment is interesting I'll look at it more closely to see if I can determine what it is.

We've only had the boat for about a year and haven't had the alignment checked. The survey a year ago didn't mention any issue with the shaft.

I'm also planning to replace the motor mounts (I suspect they're original, i.e. 15 years old) so the alignment would be done then.

 

[jaysweet]

My opinion: I think it's fine that so many people like their dripless seals. I have nothing bad to say about them. But my experience with the old school stuffing box has been that it's almost trouble-free. I just don't see the point in going to all the trouble and expense of replacing the old stuffing box with an expensive dripless seal if your old setup works well. Ours is 18 years old, and I've replaced the flax twice. Big deal! It runs and runs and... runs. It's never warm to the touch, and if I get too many drips, I tighten it up a bit. No big deal. At this rate, the shaft might be worn enough to replace in 50 years. I probably won't own the boat then...

On another topic, there are plenty of boats I'd love to own, but never will because they have sail drives. Direct drive = peace of mind.

How's that for grouchy old man opinionating?

 

[Ralph Johnstone]

Your comment about alignment is interesting I'll look at it more closely to see if I can determine what it is.

If you're the kind of guy that likes to get your knuckles ripped, torn, and mangled, attached is a simple alignment procedure which I use every five, six, or maybe even seven years, if and when I can remember. I'm obviously not into this in a religious way as I did an alignment job a year after I got the boat from the factory and it was way out in angular alignment (0.010") at the flanges. Ever since, it's never changed by more than a thou. every few years if at all.

The survey a year ago didn't mention any issue with the shaft.

Engine surveys are usually done separately from a general survey. Done by engine mechanics

I'm also planning to replace the motor mounts (I suspect they're original, i.e. 15 years old) so the alignment would be done then.

Engine mounts do not have to be done based on hours. If they do not have oil or fuel on the mounts, they are unlikely to need replacement. If your engine alignment doesn't change over the years, your mounts are likely still good. If you still have the original 3/8" clearance, you should still be good as shown below :

If you don't have problems with vibration, they're probably still good. This mount is one that was replaced due to fuel damage over several years.

The above mount info is for a 2GM20F. There may be a difference for your larger engine. Shaft alignment will be the same.

Three of my mounts are 24 YO and the replaced one is 21 YO with 2400 engine hrs. and everybody still seem to be fine.

Remember to check your cutlass bearing when you're out as shaft misalignment and an out of balance prop will eat your bearing.

 

[Stu Jackson]

Has anyone replaced the hose on theirs and, if so, what size and type of hose did you use (metric or Imperial)?

Yes, there is a special heavy duty hose for this, IITC it's made by Buck Algonquin, Google for it. Size depends on your boat, get a manual or measure carefully compared to what is available (i.e., they may not even make it in metric).
I know for sure it's been discussed on this forum, also check here: Marine How To - DIY for Boaters - Marine How To

 

[Tally Ho]

I'm planning to re-pack the stuffing box on our 2007 H41AC some time next year when I can get it hauled out. While I'm at it, I should probably replace the hose, too. The hose is about 5-1/2" long and I measured the O.D. as 3" and O.D. of the snout at the aft end as 2.725". The hose O.D. seems reasonable but the snout diameter seems odd. I measured using vernier calipers that I keep on board.

Has anyone replaced the hose on theirs and, if so, what size and type of hose did you use (metric or Imperial)?

View attachment 211497

Also, there appears to be some discoloration (possibly even some build up) on the shaft right where it enters the gland. When repacking a stuffing box, has anyone found a wear groove or scoring on the shaft and, if so, how did you go about addressing it? I suppose that the hose could be shortened by a small amount to get the packing to ride on a different part of the shaft.

I went the route of replacing the stuffing box hose, and repacking my stuffing box when I replaced my shaft a few years ago. The hose, as mentioned, is a thick-walled hose. I believe it will be one size throughout, but can be snugged down on the end that is the loosest. The first video shows the condition of the old hose.

This video shows the installation of the new shaft, stuffingbox, etc.

After running that for a while, I decided to try the Volvo Penta shaft seal…very simple design, pretty sturdy rubber stuffing box that doesn’t drip. I am very happy with the upgrade and am pretty confident in the design and construction of the seal. I was worried about the bellows on the PSS design (and truth be told, I didn’t want to spend that much money).

Greg

 

[jssailem]

I had been thinking of replacing the stuffing box with a dripless seal. However, after reading more about it and its failure modes, I decided that the stuffing box was easier to deal with if something goes wrong while underway, especially far from shore.

This is a sensible consideration.

I reached a similar conclusion but based on my boat conditions. While I am interested in the engineering of Dripless Seals, and even have one purchased, my thinking about the install and the potential of having to service it as some point, I am talking my self out of the install.

In my case the engine sits above the stuffing box, and servicing the unit is a challenge. At the present the engine is out of the boat. With access easy, the install of the dripless means I will have to remove the shaft to have a new coupling installed. I may find I also have to replace the shaft. Getting the shaft out of the boat could be a problem. The install of the dripless seal is one of those actions that could cause a case of project creep.

While still on the fence, I am leaning to keeping the standard stuffing box.

 

[Dalliance]

I'm planning to re-pack the stuffing box on our 2007 H41AC some time next year when I can get it hauled out. While I'm at it, I should probably replace the hose, too. The hose is about 5-1/2" long and I measured the O.D. as 3" and O.D. of the snout at the aft end as 2.725". The hose O.D. seems reasonable but the snout diameter seems odd. I measured using vernier calipers that I keep on board.

Has anyone replaced the hose on theirs and, if so, what size and type of hose did you use (metric or Imperial)?

View attachment 211497

Also, there appears to be some discoloration (possibly even some build up) on the shaft right where it enters the gland. When repacking a stuffing box, has anyone found a wear groove or scoring on the shaft and, if so, how did you go about addressing it? I suppose that the hose could be shortened by a small amount to get the packing to ride on a different part of the shaft.

I replaced my shaft log hose some years ago. You need to use hose intended for that purpose. It’s much thicker than any other kind of hose. I think the old shaft log hose in my boat may have been a piece of ordinary exhaust hose and that is what West Marine tried to sell me when I asked for shaft log hose. I sensed something off about what they were telling me and came to this very forum for info. I ended up ordering Buck Algonquin brand, possibly from Defender or Jamestown, but I believe this site now carries it too. It came in a 12” minimum length I had to cut down to fit. Don’t recall the diameter and I have a different boat, so it may not be the size you need anyway.

The outside diameter variations you are measuring may just be from years of hose clamp compression and outside diameter is not the one you need. Loosen the clamps and pull it apart enough to measure inside diameter.

Build up on the shaft can be cleaned off. Scoring is another issue. Potentially serious enough to require replacing the shaft as it creates a weak spot.

 

[Terry Cox]

How's that for grouchy old man opinionating?

Count me as another one in your category. Our 1991 boat has the original bronze stuffing box and it works well. I've replaced the stuffing material three times over the years since we purchased her in 2002, not because it needed replacing, but because I do it when I haul the boat every seven years to redo the bottom. And, like you, if the drips seem excessive, I just tighten the box a flat or two. I also use PTFE material as opposed to plain flax. Seems to be a better lubricate, IMHO.

 

[CharlieSea]

Ditto, the reply on the saildrive. They are easier, i.e cheaper for manufacturers but a pain for owners, won't have one. It's like iron keels, all about the Benjamins. My 2005 Hunter 27-3 shaft log hose looks good for now. Will replace some time in the next few years. Has anyone replaced or pulled the shaft on a 27-3? Is it necessary to drop the rudder to pull the shaft?

Dripless seals are great and if you have one good for you. Mine is an "almost' dripless seal. Installed 3/16" Gore brand packing. After the initial black spit, a little snug and not it is almost dry, The shaft runs cool. The tray under the shaft log is full of sham-wows and collects any water; empty occasionally. The 1/2" PVC is only to keep the container from shifting. Many hours and perfectly dry bilge.

 

[Ralph Johnstone]

Same thing here. I think the most important thing is to have a mirror like finish on the shaft area in contact with the packing to keep it dry.

 

[dkinzer]

I had a chance to examine the stuffing box and stern tube again today. I cut away a small amount of the hose at the aft end. Doing so revealed that the stern tube is necked down so that the portion that the hose mates to is smaller diameter than the part aft of the hose. I estimate that the difference in diameter is approximately 1/4" on the O.D. This makes sense now as I had gotten a reply from the SailboatOwners store saying that the stuffing box hose on the H41AC should be 2-3/8" with a 1-1/4" diameter prop shaft. This matches what I have observed.

I also spent some time cleaning the prop shaft where it exits the stuffing box. Some had expressed concern that it looked like bronze being transfered from the nut to the shaft. I'm happy to report that the deposit came off easily using some ScotchBrite. An "after" photo is attached.