Prop shaft re-seal OMC Cobra

[Tex Pat]

I have a 1994 OMC Cobra HO 5 ltr. It is leaking lower unit oil from the prop. I assume it's the prop shaft seal. I had just changed the l/U oil and there was no water in it, but I guess the seals went bad over the winter.

How difficult is it to pull the bearing carrier and replace the seals? Any advice is appreciated.

 

[Don S]

Re: Prop shaft re-seal OMC Cobra

Since you mention it's a HO 5.0L, I would guess you have a 93 engine/drive package since 94 didn't have them.
Does your outdrive have a raw water pump on the back of the drive or is the raw water pump belt driven on the engine?

 

[Tex Pat]

Re: Prop shaft re-seal OMC Cobra

Don -
Raw water pump in on the back of the outdrive, under a triangular cover with 3 or 4 bolts as I recall. It must be a 93 then, as it has 5.0 HO Cobra all over it.

 

[Tex Pat]

Re: Prop shaft re-seal OMC Cobra

A local shop did it for me today. Said they replaced the two seals on the shaft and an o-ring. I don't think that is the entirely correct way to fix the problem, but I am betting it works for now. They did it quickly though. Plus I am getting the prop re-worked and balanced; that had never been done.

 

[Gary H NC]

Re: Prop shaft re-seal OMC Cobra

If you got it fixed that fast this time of year you did great! Hopefully they did a pressure-vacuum test. Just check your gear oil for water intrusion after the first few hours of running. You should be good to go..

 

[DHPMARINE]

Re: Prop shaft re-seal OMC Cobra

Sorry you have a shop you don't trust.You need one you do trust..To reseal a propshaft you use two seals,one large o-ring,as well as 4 smaller o-rings they might not have listed.

Because ALL the seals are that old,I would have suggested a complete reseal,and that is $$$$$.

DHP

 

[Tex Pat]

Re: Prop shaft re-seal OMC Cobra

I 'll check for water in the lower unit after my next run. Hopefully this will be my only fix this year. Never had any problem with this boat and I've owned it since 1998. I have maintained it well over the years though with oil changes, fuel filter changes, plugs, water pump impellers, lower unit oil changes etc.

The bellows are orginal, as is everything else. I had the u-joints lubed this year too and he said the bellows were fine for now, but that I should change them next year or so.

Any other advice or comments?

 

[Gary H NC]

Re: Prop shaft re-seal OMC Cobra

I would say 9 year old bellows are way overdue...
I would keep a close eye on them...