1985 Hunter 28.5...............I have a new(er) yanmar 16hp diesel. I know very little about it.(bought the boat 2 months ago) I have noticed that there is water dripping from a pair of white almost looking like compression type fittings where the prop goes into the rubber housing before it goes through the aft hull. What canbe done to stop this water leak?
prop shaft leaking
- Thread starter machopekin
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Try tightening them.
Mac: Try tightening the packing. These two nylon nuts screw into each other. There is a packing material between them. When you tighten the forward nut it fills the gap between the shaft and the packing material that rides on the shaft. If you cannot tighten this down any further it is probably because the packing material is nearly all gone. In this case, you need to remove any existing packing and repacking it. This may be best left to a pro if your boat is going to be in the water. It normally takes a yard about 1 hr to do this. The packing material is about $10 for the teflon stuff. NOTE: There is suppose to be a cotter pin that goes through a hole in the forward nut and into the aft nut when they are aligned properly. This is to prevent the nut from backing off accidently.
Mac: Try tightening the packing. These two nylon nuts screw into each other. There is a packing material between them. When you tighten the forward nut it fills the gap between the shaft and the packing material that rides on the shaft. If you cannot tighten this down any further it is probably because the packing material is nearly all gone. In this case, you need to remove any existing packing and repacking it. This may be best left to a pro if your boat is going to be in the water. It normally takes a yard about 1 hr to do this. The packing material is about $10 for the teflon stuff. NOTE: There is suppose to be a cotter pin that goes through a hole in the forward nut and into the aft nut when they are aligned properly. This is to prevent the nut from backing off accidently.
Don't be misled...
...by what Steve says. He's correct, but I'm sure he means that you need some water to drip in because the water provides lubrication to the shaft in the stuffing box. Otherwise, it will heat up and score the shaft. The proper amount is 6 - 10 drops per minute while underway (that's a drop of water every 6 - 10 seconds). The water will eventually accumulate and will find it's way to the bilge.
...by what Steve says. He's correct, but I'm sure he means that you need some water to drip in because the water provides lubrication to the shaft in the stuffing box. Otherwise, it will heat up and score the shaft. The proper amount is 6 - 10 drops per minute while underway (that's a drop of water every 6 - 10 seconds). The water will eventually accumulate and will find it's way to the bilge.
One drop per minute is sufficient . . .
I always find it expedient to do a little research on the intranet, Google being my favorite search engine. If you search for "stuffing box", you'll get about 10 pages of hits. Tom Wood of Sailnet suggests 4-6 drops/minute. However, Don Casey with Boat/US and Aloha Owners Association suggest 2-3 drops/minute. Moore Marine Consultants, DIY-Boat, Catalina 34 Owners Association, and Practical Sailor all state that one drop/minute is sufficient. All state that you should not have any leaks when the shaft is not turning. I think the common thread is that too much water is bad for your engine. If your shaft is dripping excessively while turning, it will create a fine spray that will be ingested by the engine as well as end up on everything else in the engine compartment. Water is corrosive, and if you are in salt water, much more so. So keep thinking that "less is good".
I always find it expedient to do a little research on the intranet, Google being my favorite search engine. If you search for "stuffing box", you'll get about 10 pages of hits. Tom Wood of Sailnet suggests 4-6 drops/minute. However, Don Casey with Boat/US and Aloha Owners Association suggest 2-3 drops/minute. Moore Marine Consultants, DIY-Boat, Catalina 34 Owners Association, and Practical Sailor all state that one drop/minute is sufficient. All state that you should not have any leaks when the shaft is not turning. I think the common thread is that too much water is bad for your engine. If your shaft is dripping excessively while turning, it will create a fine spray that will be ingested by the engine as well as end up on everything else in the engine compartment. Water is corrosive, and if you are in salt water, much more so. So keep thinking that "less is good".
Dripless shaft seal?
Tightening up the gland nut probably solved your problem, but sooner or later you'll need to repack the stuffing box, as noted in another response. Last time I had my boat hauled out, I installed a PSS dripless shaft seal, and it works really well. I kind of got tired of having a couple inches of salt water sloshing around in the bilge all the time, and the PSS unit was not particularlly expensive or hard to install. You'll probably get a few more seasons out of the stuffing box, but you might consider the dripless shaft seal next time you're on the hard for heavy maintenance. Have fun... Rick
Tightening up the gland nut probably solved your problem, but sooner or later you'll need to repack the stuffing box, as noted in another response. Last time I had my boat hauled out, I installed a PSS dripless shaft seal, and it works really well. I kind of got tired of having a couple inches of salt water sloshing around in the bilge all the time, and the PSS unit was not particularlly expensive or hard to install. You'll probably get a few more seasons out of the stuffing box, but you might consider the dripless shaft seal next time you're on the hard for heavy maintenance. Have fun... Rick
I can report on "Drip Free"
I think I said the name right. It's the clay like packing that replaces the middle ring of the standard packing. I installed it 15 years ago. I haven't adjusted it since. Still no drips. Cost? $35. Worlds most perfect product.
I think I said the name right. It's the clay like packing that replaces the middle ring of the standard packing. I installed it 15 years ago. I haven't adjusted it since. Still no drips. Cost? $35. Worlds most perfect product.
Ok So I have it almost fixed I think.....
Thanks guys, have it almost dripless now. Tightened it by hand and it decreased the drip rate drastically (when sitting idle)..... but...and it seems there is always a but...... how much can I tighten it ( is it ever too much??) There is still about 1/2 inch of space between the aft nylon nut and the fore one. Also Ihave found this "pin" but it doesnt seem to connect into anything onthe aft nut?? advice?
Thanks guys, have it almost dripless now. Tightened it by hand and it decreased the drip rate drastically (when sitting idle)..... but...and it seems there is always a but...... how much can I tighten it ( is it ever too much??) There is still about 1/2 inch of space between the aft nylon nut and the fore one. Also Ihave found this "pin" but it doesnt seem to connect into anything onthe aft nut?? advice?
packing size
I'm up to 30+ drops per minute (last year was 2 per minute) Therefore I need to act. On the 1985 Hunter 28.5 (Yanmar 2GM) what size square flax packing do I need (Do I guess 1/4")
I'm up to 30+ drops per minute (last year was 2 per minute) Therefore I need to act. On the 1985 Hunter 28.5 (Yanmar 2GM) what size square flax packing do I need (Do I guess 1/4")
GFO gore engineered packing
After reading and talking to boaters, I decided to try the GFO Gore dripless packing as a hedge between the old basic flax and going the bigger $ for the new PYI assembly. see e-marine-inc.com After your boat is hauled, remove old packing flax, inspect smoothness/clean/smooth the packing shaft area, For about $20 delivered your can get 18 inches of the appropriate diameter "engineered" packing, neatly cut to cleanly ring the shaft,insert each of the the 3 rings with the ring seams at a 1/3 offset around the shaft, hand tighten packing "cup" to modestly snug, tighten locknut. As you go back into the water, It can leak some initially as it swells to a stop or you may need to snug up a little more. It can use some running time, Just watch it for a while during, after operation and adjust accordingly. Read the instructions on the packaging and at sellers website.
After reading and talking to boaters, I decided to try the GFO Gore dripless packing as a hedge between the old basic flax and going the bigger $ for the new PYI assembly. see e-marine-inc.com After your boat is hauled, remove old packing flax, inspect smoothness/clean/smooth the packing shaft area, For about $20 delivered your can get 18 inches of the appropriate diameter "engineered" packing, neatly cut to cleanly ring the shaft,insert each of the the 3 rings with the ring seams at a 1/3 offset around the shaft, hand tighten packing "cup" to modestly snug, tighten locknut. As you go back into the water, It can leak some initially as it swells to a stop or you may need to snug up a little more. It can use some running time, Just watch it for a while during, after operation and adjust accordingly. Read the instructions on the packaging and at sellers website.
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