prop shaft O ring

woosterken

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can i just remove the prop,and get to the O ring, that holds the oil in the lower houseing, or does the lower half, have to be disassembled to replace the O ring?
i noticed a small drip of oil from behind prop :(
1974 120hp mercruiser and 120/140 out drive , serial #3847664
i have the down load service manual (thanks Don S.)

woosterken
 
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Re: prop shaft O ring

Unfortunately, there's more to it than that. Pull the prop off and see of there's any line wrapped around the prop shaft. I ruined mine with some wire line that my uncle accidentally got wrapped in there and cut a groove in the prop shaft. Couldn't get it to seal with new seals. It was easier to get a new lower than fix.

To get at the seals around the prop shaft ya gotta pull the carrier out. There's also a large O ring around the carrier.
 

Don S

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Re: prop shaft O ring

I would suggest you drain all the gear lube and pressure check the drive to find what is leaking. Assuming the boat has been setting for winterization (wooster, ohio) it could be leaking from any seal above, and dripping to the lowest point you see it at.
 

Bondo

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Re: prop shaft O ring

can i just remove the prop,and get to the O ring, that holds the oil in the lower houseing, or does the lower half, have to be disassembled to replace the O ring?

Ayuh,... It's a Seal, Not an O-ring...
 

achris

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Re: prop shaft O ring

At 37 years old, I suggest that you will destroy the bearing carrier when you try to remove it, which you will have to do if it's the prop-shaft seals that are leaking (to be confirmed by a pressure test). Just buy a new bearing carrier (complete with seals) and put that in.
 

woosterken

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Re: prop shaft O ring

wow,thanks for all the help, so it sounds like iam looking at about a thousand $$$ repair :(
i will have to check what labor rates are here in my area.
this is way above what i can handle

while they have it a part should the lower shift cable be changed ? i think it is the original old style.
the bellows and impellor were changed early last summer.

woosterken
 
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Re: prop shaft O ring

Like Don mentioned, try pressure testing it first so you can confirm or not that it's from those seals.

There's a link in the Adults only on pressure testing a drive.
 

Don S

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Re: prop shaft O ring

At 37 years old, I suggest that you will destroy the bearing carrier when you try to remove it,

I wouldn't worry about that till the time comes. Being in fresh water (Ohio) it will probably come apart fine. but before you even think about taking it apart, DO THE PRESSURE TEST. Then after you find and fix the leak, pressure test it again to make sure your repair works.. Look in the manual, there is a whole section in it on drive repair.
 

Bondo

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Re: prop shaft O ring

while they have it a part should the lower shift cable be changed ? i think it is the original old style.

Ayuh,... No doubt the perfect time to get caught up with any defered maintenance...
 
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