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Prop Shaft Seal question

Posted: Wed May 02, 2018 10:50 pm
by coastie1160870
Hello All, I know that I have a 1" prop shaft, I know I need a new shaft seal..( It Leaks )... What I don't know is what the thrugh hull end of the set is..? Does anyone know what size the tube is going through the bottom of the boat..? PLEASE HELP ..!

Re: Prop Shaft Seal question

Posted: Wed May 02, 2018 11:12 pm
by Busia
That piece of pipe welded into the hull is called the shaft log. Doesn't matter what size it is, you're not going to do any thing to it. What you have is a packing gland that seals the rotating shaft. It should leak about one drip every few seconds while the shaft is spinning. It has to drip to lubricate the shaft. If it drips too much you can tighten the packing. Loosen the jam nut and tighten the packing nut. Then tighten the jam nut. If you have it too tight the shaft will get hot as it spins. If you can't tighten it to stop the leaking you will have to change the packing. You should have 1/4" X 1/4" packing. Not a complex job, but awkward to reach. There are threads on this site on how to do it.

Re: Prop Shaft Seal question

Posted: Thu May 03, 2018 1:37 am
by coastie1160870
Thanks, But... What I have is a "DRIPLESS" shaft seal with a water line going back to the engine, not a traditional stuffing box.. The rubber boot as I recall, seals on the Shaft Log, and the bushing seals to the shaft. There is some presure put aginist the bushing to seal it, as it turns.. Now keep in mind, this is how it looks to me, from the deck height, and memory of last year.. If no one knows what the ends measure then I'll have to drive up to the boat, drag a ladder, climb up and in, make measurements.. which is a little bit of a challenge for me, being a double amputee.. But I hate to pay someone to fix it, if I can do it...

Re: Prop Shaft Seal question

Posted: Thu May 03, 2018 9:41 am
by EWRice
You should only need the brand of seal and shaft diameter to order a replacement. Unless the hose/bellows needs to be replaced because of a tear. If my memory serves me right, the shaft log is 1.875" o.d.

Re: Prop Shaft Seal question

Posted: Thu May 03, 2018 12:05 pm
by Busia
As Emily would say " Never mind".

Re: Prop Shaft Seal question

Posted: Thu May 03, 2018 9:56 pm
by Rockit
I have to be missing something. How do you check the stuffing box while the shaft is turning? Do you do it while the boat is moving? I can't see shaft drips from the deck so I have to do it in the engine compartment with a time piece. Dong this while underway strikes me as very unsafe. I check it when the shaft is not turning (and the engines are off) and figure it should drip about once every 60-90 seconds.

Wisdom will be welcomed.

Thank you.

Re: Prop Shaft Seal question

Posted: Fri May 04, 2018 3:34 am
by Busia
To work on the boat by myself all I do is make sure it is tied to the dock securely. I can put it in gear and add power slowly. Then just pull against the dock. Hopefully the shafts won't drip when they are not turning and just a little when they do turn. Better too loose than too tight.

Re: Prop Shaft Seal question

Posted: Sat May 05, 2018 10:38 pm
by Rockit
Thank you. Correct, a little water in the bilge from the shaft seal is no big deal.

The boatyard tried to sell me on dripless stuffing boxes, but at $500 a pop, I can live with some bilge water.

Re: Prop Shaft Seal question

Posted: Sun May 06, 2018 8:49 pm
by coastie1160870
Hi Guys.. I didn't get a choice.. The boat came drip;ess, untill... it wasn't dripless, anymore..! L.O.L. So late in August last year I noticed that everytime we took the boat out, the bilge alarm would come on.. Being that wife was not in to driving the boat, and for other reasons, wasn't a lot of help.. (to no fault of her own, mind you..) I was checking the shafts for water at the dock, every time, before we went out.. NOTHING..! NOT A DROP OF WATER, ANYWHERE.. We would get underway, and BAM..! Bilge Alarm..!! Robert E. Custer II came over and we went for a ride, this time he opened the hatch and there it was.. My inboard water shower..! At the tranny end of the shaft seal, I had a shower going full force, except... as soon as I took the engine out of gear, it stopped.!! SO... Now I'm wondering... do I need to replace the entire thing, ( PSS SHAFT SEAL ) or could I use a repair kit..? The difference is about one hundred dollars, each..! Has anyone ever used a repair kit.? What did it actually do ..? Will that solve my problem... Keep in mind, I'm new to this boat, just bought it last July 3rd.. (2017) Thanks

Re: Prop Shaft Seal question

Posted: Tue May 08, 2018 7:15 am
by bill
BigM
Have you tried measuring the shaft end play :?: The shaft may be loose in coupling attached to the transmission?
Have someone shift the trans forward and reverse while secured to the dock. Look for fore and aft movement of the shaft.
If this is excessive find and fix the problem.
THEN proceed.
On the mechanical seal the set screws on the front SS collar can be loosed to allow more pressure on the sealing surface of the seal.
Good luck
bill