Packing gland how often to replace

dlochner · Apr 4, 2019

No need to repack. Just tighten the nuts. Over time the packing compresses and leaks develop. It should drip a little with the motor running. The water cools and lubricates the gland.

dehler25 · Apr 4, 2019

AS Dlochner stated tightening the gland is needed , but only enough to bring a slight drip. After tightening and motoring a bit check the temp as overtightening will generate heat along with a boatload of trouble.

Don Crowther · Apr 4, 2019

When I tighten/adjust my packing gland it only takes less than a 1/2 turn to stop the flow. It still drips but only a couple of drops a minute. Just be careful not to over tighten.

rgranger · Apr 5, 2019

dehler25 said:
.... along with a boatload of trouble.

haha

Blitz · Apr 5, 2019

Ask your yard what type of packing they used. The newer graphite Packing are much better for heat dispersement such as:
Western Pacific Trading Graphtex Ultra (GTU) Flax Shaft

Seems like you just need to tighten it a little bit to get the lower flow. Sometimes it takes a few tries to get it right.

JoeWhite · Apr 5, 2019

I replace it every 3 years when I haul out for bottom painting.
I use 1/4" Gore Tex, 3 layers and before reinstalling the nut, I fill the log shaft with Lana-cote.
The nut is only hand tight. there is hardly any dripping when on the way and no dripping when shaft is not turning.
Visit this site for more info http://www.mei1970.org/saillavie/stuffing-box

Michael Davis · Apr 5, 2019

wilf said:
How often should you need to repack these?

You just keep tightening the packing nut a bit at a time until it eventually bottoms out. Then it's time. I've over a 1000 hrs. under power since mine was done and still lots to go.

Richard19068 · Apr 5, 2019

good info here on packing material and adjustment:
https://marinehowto.com/re-packing-a-traditional-stuffing-box/

NYSail · Apr 6, 2019

Remember you can always tighten so just gradually tighten the nut and see how it performs. I would maybe give an 1/8 of a turn at first and see what happens. Inspect as you are motoring, then put boat in neutral and give another 1/8 turn..... or not.. Also when I had a traditional stuffing box I made sure to apply a good coat of Teflon grease to the threads and nut so they would move nicely when you want them to...... and don’t forget to apply to all surfaces of the nut (sides) otherwise the salt water dripping will corrode and make adjusting a chore to do.

Good luck
Greg

cagreen75 · Apr 8, 2019

Since the packing is rubbing directly on the propeller shaft it will eventually wear a deep groove into it and at some point the shaft will need to be replaced. Over tightening the packing nut will accelerate shaft wear so be very careful to not tighten the nut too much. My thought would be to install a mechanical seal. They are more expense up front but typically last for years without any attention at all other than a visual inspection. While a packed shaft seems like a better bargain it actually my not be if you have to replace the propeller shaft. The other thing about a packed shaft is as it wears the gap between the shaft and stuffing box increases. If this happens you will need to put wider packing material in to make up the space left by the worn shaft. The other way of dealing with that is to leave the packing in there and just add more to the top when your packing nut bottoms out. Keep in mind that doing this prevents you from seeing how worn the shaft is and at some point the shaft may become so worn that it may break. Mechanical seals eliminate all of those problems.

Michael Davis · Apr 8, 2019

cagreen75 said:
Mechanical seals eliminate all of those problems.

But they do have their own problems. I'm torn between them. Traditional is much easier to fix while away on a cruise.

dlochner · Apr 8, 2019

Michael Davis said:
But they do have their own problems. I'm torn between them. Traditional is much easier to fix while away on a cruise.

I've had both a traditional packing gland and a PYI Shaft Seal.

The problem with wearing on the propshaft is more of an issue with bronze shafts than SS shafts, because bronze is softer.

Dripless seals like the PYI Shaft Seal work, but the hose should be replaced about every 7 years.

The traditional seals may also have a hose coupling with a longer life.

When I replaced a traditional stuffing box with a Shaft Seal on a Sabre 30, I also replaced the propshaft (but for other reasons than wear) mostly because accessing the stuffing box and working on it was a real PITA. With the Shaft Seal, it was easy to inspect and didn't need any work for long periods of time.

So, if you have a SS shaft and if you can easily access the stuffing box, the traditional stuffing box is a much less expensive way to go.

TomY · Apr 9, 2019

wilf said:
Anyone advise me on this, I had my boat hauled 2 years ago and done some work on it myself bottim paint etc but had the yard replace the packing gland as I hadn't done it before and wanted to make sure it was done correctly , it leaked a little at first which I believe it supposed to, a few drops per minute? I tightened it a little bit after a couple weeks,
anyhow last couple of times out i motored for maybe 30 mins and it probably had a gallon+ of water in the bilge ,
i wasnt sure if it was from the gland or something else so I placed a soup bowl directly under it and after 20 mins of running the motor it was full and overflowing, it doesn't leak when not running the motor,
How often should you need to repack these?

The new packing materials work well. I re-packed the stuffing box on my boat over 10 seasons ago, when I had the engine and shaft out(also replaced the cutlass bearing).

A slight tightening every few years is all the maintenance the box has taken in that time.

Today, I have the shaft out for replacement but the stuffing was still working fine. The shaft is badly worn at the cutlass bearing area which I why I'm replacing it. It was a little loose on the cutlass in that area (stainless steel shaft), 10 years ago.

I'll repack the box when I install the new cutlass and shaft. I will expect at least 10 years before it needs repacking. Less than 100 hrs average use per season.

NYSail · Apr 9, 2019

Years ago with my old boat, the prop shop talked me out of the drippless even though they sold them..... my shaft was ss and had a slight score in it so he extended the hose bringing the point of contact to a different location rather than selling me a new shaft. Worked out perfect for the 10 years I had the boat and is still going strong with no problems. New boat has a Volvo drippless gland.... I love it and think its worth checking out.

Greg

Davidasailor26 · Apr 10, 2019

NYSail said:
New boat has a Volvo drippless gland.... I love it and think its worth checking out

. I love ours too. Just lubricate and burp once per season, no other routine maintenance until it needs replacement. Ours has 5 seasons and has never leaked a drop.

NYSail · Apr 10, 2019

Davidasailor26 said:
. I love ours too. Just lubricate and burp once per season, no other routine maintenance until it needs replacement. Ours has 5 seasons and has never leaked a drop.

Agree.... funny how this unit gets little talk time. But know, less grease is better. I do know someone that over greased and inserted tube too deep and ended up clogging cutlass bearing so no water flow.
Greg

Davidasailor26 · Apr 10, 2019

NYSail said:
I do know someone that over greased and inserted tube too deep and ended up clogging cutlass bearing so no water flow.

That's a handy tip. I use the MacDonald's straw method, putting an inch or two of grease into the end of the straw, pinching the end, and sliding it about 1/4" under the seal. Then I just squeeze whatever grease I can out of the straw and spin the prop a little by hand.

NYSail · Apr 10, 2019

I just use the cut corner of the package the grease came in and do just like you. From what I gather, the gentleman I am referring put it much deeper in and infused much more..... More is not always better!!

Justin_NSA · Apr 10, 2019

NYSail said:
Agree.... funny how this unit gets little talk time. But know, less grease is better. I do know someone that over greased and inserted tube too deep and ended up clogging cutlass bearing so no water flow.
Greg

My Lasdrop Gen II gets even less talk time. I attribute it to they only recently started making them for smaller shafts. No burping or grease needed. The only maintenance LasDrop mentions is:
When vessel is out of the water for any period of time, it is recommended seal is washed down with fresh water.