omc cobra prop shaft seals

[sea wolf]

i need to replace the prop shaft seals on my 87 cobra {water in gear lube}. there are 2 seals which go back to back. what i'm not sure about is how do the new seals go in? i don't want to put them in backwards as once there in that's it. if i have to pull em again i'll need to order new ones. i've already pulled the prop shaft housing. anyone know?

 

[johnkc]

Re: omc cobra prop shaft seals

the garter spring on the seal goes towards the gear lube on the inner seal and then the garter spring goes out on the outer seal

 

[sea wolf]

Re: omc cobra prop shaft seals

thanx john. i had them replaced last yr. & was wondering if someone put em in backwards. have u ever seen one of these leak around where the prop housing on these omc's bolts in? there's 4 bolts that have o-rings. i removed the bolts & put in new o-rings. i also changed the o-ring around the housing. i have the upper & lower split. i set the lower half in a container of water. i could see an air bubble around the prop seal, so i'm changing them. there's no gear lube in it, i completely drained it. after removing the unit from the water i removed the drain plug. water drained out, & it was brown in color. could it be just traces from the old gear lube that is turning the water brown? i would estimate a cup of this stuff drained out.

 

[johnkc]

Re: omc cobra prop shaft seals

sea wolf ,it is very common to find leaks at the o-rings. also make sure you replace the 2 big o-rings that seal the upper to lower.

 

[sea wolf]

Re: omc cobra prop shaft seals

what's a good sealer for these o-rings. the ones that came with the seal kit look like they won't do a very good job. they seem too small. i think the o-rings are part of the reason why i keep getting water in the gear lube. i went through this last yr. with these damn things. i put gasket sealer on them, which didn't work. i was thinking of putting some silicone around the bolt heads, but there's no way to get at them once they're bolted in.

 

[Lark40]

Re: omc cobra prop shaft seals

If you are going to be maintaining that sterndrive, you might consider buying the Stevens S-34 pressure tester and also their vacuum tester. These are sold on marine sites.<br /><br />Not cheap, but you would know for certain if you had fixed the leakage.

 

[sea wolf]

Re: omc cobra prop shaft seals

lark, i've cosidered buying the pressure tester. but, i may take it to a dealer to have it tested. anyone know what it would run me $$$$$ wise to have it done?

 

[johnkc]

Re: omc cobra prop shaft seals

sae wolf ,i use merc's perfect seal .but it is a large can and kinda expensive.i have also used aviation sealer that comes in a small 2 oz.{?}bottle or liquid permatex ,i forget the permatex part #.as long as you use a heavy bodied brown liquid gasket sealer you will be o.k. ,don't use silicone.is your seal kit original omc or after mkt?

 

[sea wolf]

Re: omc cobra prop shaft seals

i believe it's aftermarket. i'm thinking of using permatex black on the o-rings & using the liquid sealer on the bolt heads, using an artists brush to get at them once it's bolted in. i'll let it set up overnite & hope for the best. thanx for your help.