PDA

View Full Version : Repacking doesn't stop drive shaft seal leak; some pitting on shaft... what to do?


MikeR
07-30-2012, 01:57 AM
We bought a 2001 X-30 a couple of years back and I've been slowly working through all the gremlins. When we bought it the drive shaft packing was leaking-- I figured an adjustment or repacking would solve the problem.

I tried a couple of times to adjust the original packing to stop the dripping when not moving, but had no success so I repacked with the Gore material.

When I adjust it to have the slow drop (evey few seconds while running) it still leaks when I am not running. Sometimes I can tweak it a little tighter to stop the drip when not running, but then after running and stopping it is leaking again... The lock nut is tight so it is not loosening itself.

We had a situation this season where the bilge pump failed while we were away from the boat for about 8 hours and got a scary amount of water in the bilge (no damage, but glad we weren't gone any longer!)-- so I need to get this fixed before something worse happens.

I decided to try repacking again and when I got the old packing off I noticed that there is some pitting on the shaft in the area of the packing/seal.

Could this be my problem? Will this pitting make it impossible to seal correctly? If the pitting is a problem, do I have to replace the shaft to fix it?

Or do I just need to crank down the packing a lot tighter (with no drip even while running)?

Any thoughts, advice, experience would be appreciated!
(Note the pictures below are after I sanded for about a minute with some very fine sandpaper-- so the pits are not going to come out easily...)
Thanks,
Mike

FrankSchwab
07-30-2012, 12:07 PM
If you have room, I'd try getting a longer stuffing box hose (the rubber "boot" between the shaft log and the stuffing box), an inch or so longer would move the packing away from the pitted area.

Alternatively, perhaps now is the time to look into a dripless shaft seal. If the actual seal that rides on the shaft ends up getting located someplace other than the pitted area, you have a nice upgrade and solve the problem at the same time.

/frank

MikeR
07-30-2012, 12:27 PM
I thought about maybe cutting the hose down a little shorter... Longer might work too but it is already pretty tough to get a wrench on the packing nuts with the V-drive transmission in there.

I'd definitely have to pull the shaft (and rudder to get the shaft clear) to put a longer hose on; I was wondering what my chances are of cutting the hose shorter "in situ" are... It's pretty cramped under there, I'm not likely to get a good square cut and if the cut isn't square I'm not too confident that the packing nuts would be straight; and then I might not be any better off than I am now.

Hmmm, I'll have to think about these options, certainly a lot cheaper than a new shaft!
Thanks,
Mike

FrankSchwab
07-30-2012, 09:08 PM
Shorter would probably work also. I don't know how square the cut would have to be - if it's hose clamped on (it's been too long since I looked at mine), the cut wouldn't have to be very good at all.

I know what you mean about getting wrenches on the nuts; I've seriously considered cutting my own wrenches out of 1/4" aluminum to make it reasonable to adjust them.

I don't think you have to pull the rudder to remove the shaft - if things are still straight, I think the shaft slides out right alongside the rudder. You should be able to eyeball it.

/frank

Kell
07-30-2012, 10:31 PM
How many rings of gore packing rope did you install? Did you cut at a 45 degree angle and off set the rings? I would be surprised that those nicks on the shaft would cause that much water to pass.


Sent from my iPad 2 3G using Tapatalk

CCAnderson
07-31-2012, 10:52 AM
The pits are the culprit. When you tighten down the packing it consolidates and fills in the little pits stopping the leak than when running the pits grind away at the packing. the shaft is spinning very fast, any irregularity in the surface finish will accelerate the wear on the packing

My advise is to not mess with the shaft or log and live with the slow leak and repack every year if the leak rate is tolerable. Keep in mind packing is supposed to wear and it needs scheduled servicing much like an impellor.

DH9441
08-01-2012, 04:01 PM
How often is it supposed to be changed. I just chaged mine and I doubt it was ever done.

MikeR
10-10-2012, 11:56 AM
Update: I decided to follow FrankSchwab's advice and get the dripless seal as we run in salt water about 50% of the time and the less salt _in_ the boat the better. Unfortunately, when I went to install it I could not get the shaft coupler off of the end of the shaft. I had a trip planned the next weekend and had to get the boat ready.
So I gave up on the dripless and used fine sandpaper to polish the shaft. I then installed a new Gore seal -- 3 rings with ends offset around the seal (although I didn't do a diagonal cut as Kell suggested, I didn't see his post before I did it). This is exactly what I had put in 2 years ago with no success at reducing leakage.
The good news is that the polishing made a huge diffference. The seal works great now. In fact, almost too good. At least within the first 10 hours of running I can't get the seal to even drip... even when the packing nuts are only loosely hand tight and the shaft turning at idle I don't get a drip. From what others on this forum have posted it seems the Gore packing is capable of pretty high temps and some people have suggested that they tighten their Gore until it doesn't even drip, so I guess I'm not too worried about the lack of drip... when running the packing nuts don't appear to be getting too hot either.
So now I've got an "almost" dripless Gore seal that is working great. Polishing the pits out of the shaft made a huge difference. And I have a nice OJ Dripless sitting on my workbench! Maybe that will be a project for next season, if I can ever figure out how to get the coupler off (I know there's a lot of posts on the forum about couplers and the pain involved in removing them :( )

pbgbottle
10-12-2012, 10:18 PM
mine was leaking like a biache .from wear on the shaft also , bad alignment .
Mines a direct drive and i had fairly good access. so I just put a longer piece of hose in and went with the gortex. I also have almost no visible drips. But do have a few ounces of water in the bilge at the end of the day.