Cobra Prop shaft seal

nealgass

Recruit
Joined
Jul 15, 2009
Messages
4
I have a 94 four winns with a 3.0 and a cobra outdrive (OMC).
It has been so great and really trouble free, until this morning.
Had the boat out yesterday and this morning noticed milky outdrive oil spilled out from behind the prop when I lowered the drive.I checked the drive oil before I went out and it was clear and clean. Pulled off the prop and found a bunch of monofilament line wrapped around the prop shaft and a lot of it sucked in to where I believe the seal is. I removed as much as I could and the more line I pulled out,the more oil leaked out from around the shaft. I looked at the manual, but I'm unclear if this is something I can do.
I removed the 3 bolts holding the anode and removed it, loosened the bearing carrier bolts, but the next step requires a special tool (914684) and I'm not sure if the carrier screws out, or comes out in another fashion. If I get it out can I replace
the seal, or will a bunch of parts come streaming out, making an easy job a big mess? I'm king of handy and could make a tool if it would help, I'm hoping someone can shed some light on how to fix this.
Thanks, Neal
 

nealgass

Recruit
Joined
Jul 15, 2009
Messages
4
Re: Cobra Prop shaft seal

This is the nest of line, but I'm still stumped as to what the next step might be.
Thanks
 

Attachments

  • OMC Cobra.jpg
    OMC Cobra.jpg
    89.5 KB · Views: 1
  • OMC 2.jpg
    OMC 2.jpg
    106.3 KB · Views: 1
  • OMC 3.jpg
    OMC 3.jpg
    100.9 KB · Views: 1

sea wolf

Lieutenant Junior Grade
Joined
Apr 3, 2002
Messages
1,219
Re: Cobra Prop shaft seal

There are 4 bolts that hold the housing in place. You'll need a long socket extension to get to them. Plan on not only replacing the prop shaft seal, but also the o-ring that fits inside the lip of the housing, & the 0-rings that go with the 4 bolts. Soak the housing with some PB Blaster for a few hours & u may be able to just pull the housing out with a good yank. You do not need to remove the prop shaft. When reinstalling the housing make doubly sure that all the bolt holes line up perfectly, or you'll be taking the housing out again. You can't twist it to line up the holes. And make sure it's fully seated. Don't try to draw the housing in with the bolts, or you'll have big problems if one of them snap. Tap on the housing with a rubber mallet to fully seat it in place. It's not a major repair, but can be tricky. You should gets yourself an OMC shop manuel to fully walk u thru the steps, but I've given u the jist of it. And you'll need to change the gear oil, it has water in it from the bad seal. Good luck.
 

nealgass

Recruit
Joined
Jul 15, 2009
Messages
4
Re: Cobra Prop shaft seal

Thanks sea wolf for the help.
I'm still confused except for the PB spray part!
If I look into the throat of the shaft housing, there is one bolt (red arrow on photo) at the top.
There are three holes that may be tapped, but nothing screwed into them (yellow arrows in photo)
I actually do have two manuals, but they are either too vague or the photos don't show anything like I have.
I'm scared to pull something if it screws out, or try to screw out a part thats bolted in and I cant see where.
I live pretty far from any repair facility, and even then, I don't know if they know what their doing.
Thanks again for the help- I go out to the garage every hour to try something else, but so far, no go.
 

Attachments

  • Holes.jpg
    Holes.jpg
    96.4 KB · Views: 1
  • OMC INNARDS.jpg
    OMC INNARDS.jpg
    97.7 KB · Views: 1

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Cobra Prop shaft seal

its because thats not a cobra drive.
its a cobra SX ,was a joint venture between volvo and OMC and later was simply the SX.
DO NOT attempt to pull that carrier.
it unthreads only after removing the aft lock bolt and the inner lock bolt.
the aft lock bolt,looking from the prop, is at about the 11 oclock position and is about a t27 fastener.
the inner is all the way fwd at the 12 oclock and is a 3\8ths hex.
once both locks are removed the carrier unscrews,with the special tool and a laong breaker bar,in a counter clockwise motion.
propshaft seal failure was common,the new seals also require the new driver or seal damage occurs when driven in.
 

sea wolf

Lieutenant Junior Grade
Joined
Apr 3, 2002
Messages
1,219
Re: Cobra Prop shaft seal

Oops, you're right Rodbolt. I didn't see that it's a Cobra SX. Glad ya caught that.
 

nealgass

Recruit
Joined
Jul 15, 2009
Messages
4
Re: Cobra Prop shaft seal

You guys are so awesome!
With your help I got it out. Made my own tool to get it out and couldn't believe
how much monofilament was between the seal and the prop shaft (see photo)
Kind of surprised it didn't just pour out, instead of the slow leak.
I'm not sure if the title of this thread can be changed to "cobra sx" but it sure might help some one else with an older boat like mine that has the identification markings either missing or worn off.
Thanks again, I'm sure I'll be back with more questions.
neal
 

Attachments

  • carrier.jpg
    carrier.jpg
    46.7 KB · Views: 1

boatdepot

Recruit
Joined
Jul 18, 2010
Messages
2
Re: Cobra Prop shaft seal

thanks for your post, great help for me...a couple quick follow-up questions. On boats with twin screws (counter-rotating engines) does the bearing carrier screw out counter clockwise on both drives? Does the lower unit (foot) have to be removed to effect this repair or can it be completed while still bolted to the drive on the boat?
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Cobra Prop shaft seal

Best to start a new thread with your own specific questions.
 
Top