The 1/4 inch is the wrong size for my C27, Universal 5411. The right size is the 3/16". I asked the mechanic that put in the 1/4" and he said that he pinches it down (flattens it) a little to make it fit. He only put two rings in instead of the normal three.
Stuffing box question
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Time for a new "mechanic".....
This is an easy DIY project...."Gee I know your car takes gasoline but I did not have any so I put some diesel fuel in there... Don't mind the smoking & stench its normal"
One other thing is that when I stopped the engine I wasn't getting those 2 -3 drops every 20 seconds like I was before I started the run. I think I need to continue to slowly loosen the packing nut to try to allow more water to get into the packing. My gut feel is that if the 3/16" packing was used I wouldn't be having this problem. It would just allow more water to get in.
Thumb Rule: After you put in proper packing (I believe it is 3/16); hand tighten; then with wrench go a half turn; then back it off a quarter turn. It should drip several times a minute under way (warm to touch not hot). About 30 degrees above water temerature (i.e. water temp 80 deg - packing nut 110deg F. It should drip - so make small adjustments 1/4 turn at a time. I recommend use of handheld digital temp readers - lots of other uses.
Coast Awhile - Hunter310
Coast Awhile - Hunter310
Went to the boat yesterday determined to have it hauled out and replace the 1/4" packing for the 3/16". Instead I loosened the packing nut further and ran the engine for 20minutes at the dock. With the change in the tightness of the packing nut the temp only got to 122 F. A big change from the 142 F of the day earlier. I will back it off a little further. I will change to the 3/16" packing when the boat is hauled for the winter. One thing that makes the adjustment difficult is that I will back off the packing nut and get the drip rate I want and then when I tighten the lock nut the drip rate practically stops. I guess I need to loosen the packing nut to get a higher drip rate than needed and then tighten the lock nut. This has been a frustrating experience but this is my first experience with an inboard so I'm learning as I go along. My Universal 5411 engine really runs smooth and overall is a great engine even after 32 years.
The "drip rate" you are looking for is at the front of the nut between the shaft and nut NOT at the aft end of the nut...... Sounds like your drip rate is from thread leakage which means the aft ring is not contacting the stern gland propery or was cut incorrectly.. Packing can be changed in the water by a "competent" person...
MS, that's right, I'm getting the drip at the aft end. I thought I should be getting it at the front end of the packing nut but wasn't totally sure. Could this also be partly because of the oversized packing?
Not "partly" but pretty much entirely.... I would be asking your mechanic to do this over at his cost. Anyone who thinks it is okay to "flatten" packing to make it fit should not be allowed to hold wrenches let alone work on something as critical as a stuffing box.
MS, concerning the 1/4" packing I called another diesel shop to get a second opinion and he didn't think that the 1/4" inch made that much of a difference and wouldn't necessarily change it as the first thing to do. Also upon loosening the packing nut wouldn't it be more likely that water flow would be first at the back end of the packing?
Wow you're just in an area of bad techs....
Sorry for that.... If you loosen the nut and can't get flow between the shaft and front of the nut the packing is; A) to large B) installed incorrectly........
When you go looking for a new mechanic (and, IMO, you do need a new mechanic), you don't want that one, either.
There is a reason that a particular size of packing material is specified. There is a reason they make it in size increments of 1/16".
No. If it's coming out there it indicates not that water is seeping between the packing material and the shaft (which is where it needs to be for lubrication and cooling), but between the two parts of the packing gland--which is just... leakage.
The stuffing box is really a brain-dead simple thing. This is not rocket surgery. Maine Sail is not Making Things Up, and he definitely knows whereof he speaks. Either get the proper size packing material (I recommend Gore GFO or GTU) and replace it yourself, or hire a competent marine mechanic to do it. It can be done in the water.
Either way: Get it right. Replacing a prop shaft is expen$ive. I should know: We just did it this spring. (Not, btw, because the shaft was scored from the stuffing box packing material.)
Jim
All these opinions make my head spin. It's really simple, you should be able to touch the packing nut and it not feel warm. Either you have the wrong size packing or the nut is too tight. Fix whatever's the problem. With the correct packing size and the proper adjustment, the nut should always feel "water temp" cool after extended engine operations. This is not rocket science gentlemen.
You are way over-thinking this, and believe me, coming from me that means something; I'm the king of over-thinking things.
Mainesail is an expert on this topic (and many others). Take his very valuable advice, that he's offering for free. Check out his online tutorial on repacking a stuffing box.
It's simple:
- use the right size packing;
- cut three rings the right size;
- clean out the packing nut;
- install the rings of packing properly;
- push them into the nut with your home-made pvc packing tool.
It should feel warm to the touch when running, not hot.
You can do it with the boat in the water if you have balls. Either plug the prop shaft in the water with toilet gasket wax, by diving on it; or cut a piece of bicycle inner tube to make a tie-on gasket (like a tourniquet) that you'll tie over the threads and shaft while you're working on the nut. If you use the wax, don't forget to remove it after you're done!
my packing gland is different than most of yours as mine is a flanged unit--we repacked in water more than one time so far--no one packed it before installation, as they should have-- but it will not sink your boat unless you forget to finish the work. mine had zero packing in it for over 5 yrs and didnt sink. (po told me the cutlass bearing was bad--wasnt--just the packing gland was never stuffed.)
i use gore-tex. good stuff.
i use gore-tex. good stuff.
To Repack a Stuffing Box ...............................
The water inrush when you open the gland is not that bad and once you've sealed it off, you can take the rest of the day to pack it to the utmost of perfection.
........................ in the water requires no more than a grade four reform school education at best. See below.
The water inrush when you open the gland is not that bad and once you've sealed it off, you can take the rest of the day to pack it to the utmost of perfection.
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The shaft can get 'necked'ie where the packing is agroove will form.adjustment causes the packing to compres in the groove, when in gear the prop thrust moves the shaft forward and friction=heat occurs, this will also harden the packing. if the shaft has awear groove then the gland will never work.Unsrew the nut and pull it fwd to expose the shaft where the packing runs. You got a groove right? A pro(cest moi) can fix it by minimally installing a one piece rubber seal- swedish starts with v- the seal part will be on unworn part of shaft.the pro may need to go as far as replacing shaft, ,coupling skeg bearing flex coupling bolts re allighnment etc.its a boat job right? Some early catalinas were fitted with bronze shafts-softer than stainless.If there is an experienced marine mech who has done lots of shaftline work in your area why not consult him for an appraisal? the whole system needs to be assessed as to easiest best result.Cheers
harden the packing
we repacked my rudder shaft packing gland also in water--is below water level. NO water ingress while changing it--
dont fear the ingress of water-isnt more than a 500gph pump can empty in less than 5 minutes...
dont fear the ingress of water-isnt more than a 500gph pump can empty in less than 5 minutes...
I kind of missed that. Be advised:
More precisely: The stuffing material will never be able to hold together to keep a decent seal against the prop shaft, and you will forevermore have excess drip and be replacing your packing material frequently.
If that happens it might be possible to install an over-long or shortened packing gland hose to move the position of the packing material. Then again: Maybe not. Best to try to avoid the question.
Hmmm... The GFO or GTU (same thing) I installed... three years ago? is holding up well, but that stuff looks even better. When it comes time to re-pack Abracadabra's stuffing box, I'll give Ultra-X a try.
If I can find it... I just took a quick look, and it doesn't appear to be readily-available?
Jim
I now try to recommend graphite impregnated packings with some cautions:
These cautions are on my web site at:
Re-Packing A Traditional Stuffing Box (LINK)
GFO, Duramax Ultra-X and GTU WARNING:
While I do like the graphite impregnated packings such as Duramax Ultra-X, Gore GFO or Western Pacific Tradings GTU they can be dangerous to underwater metals. I use it on my own boat but inspect the Aqualoy 22 prop shaft yearly.
[NOTE: This year I am testing a proprietary non-graphite packing that is braided from Teflon yarns and has no galvanic issues. So far it is performing as well as any of the graphite impregnated products.]
Graphite is one of the most noble metals on the galvanic scale and is basically at the top. As such anything in the drive train becomes anodic to the packing. Older "bronze" shafts, really more like a brass because they had high zinc content, can be damaged by these new high tech packings.
This damage below happened in one season with in intact prop shaft zinc. The shaft was in fine condition when packed and a year later this is what it looked like. The packing used was Gore GFO a graphite impregnated packing. If you have a bronze shaft use extreme caution with graphite impregnated packing materials.
I don't tend to see these issues with Aqualoy 22 shafting but I do see it with bronze. Please use these packings CAREFULLY, if you choose them, and do check on the shaft periodically.
It should be noted that ABYC P-6 specifically says this:
"6.7.4 Graphite impregnated packing material shall not be used because of the possibility of galvanic incompatibility with the shaft material."
That being said there are thousands of happy boaters who have had decent results with these packings but they should not be treated as a "set it and forget it" packing.
Graphite Impregnated Packing 1 seasons damage..!
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