OMC Cobra Drive-milky oil - UPDATE (not good)

I have an '87 OMC Cobra outdrive. I was just drainging the oil and unfortunately it looks a bit milky. I know that means water. The other thing I noticed was a significant amount of black sludge on the end of the fill screw. Does the black sludge help confirm water in the oil, or does it show that something else might be wrong?

Does the black sludge on the fill screw possibly show that the water is entering at that location?

Re: OMC Cobra Drive-milky oil & sludge on fill screw

Re: OMC Cobra Drive-milky oil & sludge on fill screw

That black sludge is probably stuck on a magnet. The lower drain plug (NOT the fill plug for a Cobra) usually has a small stick magnet in the plug. The sludge sounds normal and is just normal gear and clutch wear.
Once you get it drained, you need to do a pressure check to find what is leaking. Pressurize the drive to 12 to 15 PSI and spray it with soapy water, the bubbles will indicate the leak.

Re: OMC Cobra Drive-milky oil & sludge on fill screw

Re: OMC Cobra Drive-milky oil & sludge on fill screw

Don- my fill plug and drain plub both have the stick magnets if that makes a difference. Sounds like the sludge is normal.

I have never pressure tested before. I have a gauge and air compressor. What is the best way to pressure test the drive for a DIY'er like me? Any input would be greatly appreciated.

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

I just checked my bellows to see if they were still in good condition. They are, but my U-joint bellow is not connected at the stern. I assume the strap became loose and it worked itself off. I just had the boat out a few days ago and I am surprised I didn't have more water in the bilge. I am not sure how long the bellow has been unattached.

Would this account for the milky drive oil? I assume it would, but would like to check with you guys.

I can get the bellow back on, but I assume I may have major problems with the U-joints and other mechanical items. Should I take it to a boat mechanic and have him take the drive off and inspect?

What is the worst case scenario?

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

Absolutely it would. The oil seal on the driveshaft is not made to keep water out.

You are going to need to change your u-joints and gimbal bearing at a minimum. If the drive shaft going into the drive got corroded, you will need to change it too since it will never seal properly again.

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

What a bummer. I assume this is going to cost a pretty penny. I check my U-joint bellow at least a few times a year for cracks and holes. Now I have learned the hard way that I will have to check them more often and make sure the clamp has not come off.

Is it somewhat typical for the bellow to work itself free, or did my old mechanic not tighten the clamp enough?

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

larry1167 said:

What a bummer. I assume this is going to cost a pretty penny. I check my U-joint bellow at least a few times a year for cracks and holes. Now I have learned the hard way that I will have to check them more often and make sure the clamp has not come off.

Is it somewhat typical for the bellow to work itself free, or did my old mechanic not tighten the clamp enough?

Click to expand...

Could be. The clamp is tricky to get at. You need a long screwdriver or nut driver & u have to reach under the transom assy. to tighten it. And the clamp has to be in the correct position so it doesn't hit the hydraulic line for the trim/tilt when you turn the wheel to port.

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

If the u-joint bellow comes off then the entire bellhousing fills with lake water which also floods your starter motor, this happens pretty quickly and can sink a boat depending on your bilge pumps GPM ability.
Are you sure it's not the exhaust bellow your looking at?

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

Yes, I am sure it's the U-joint bellow.

That being said, I am surprised I didn't have more water in the bilge. I took the boat out a few days ago and when I checked the bilge after getting back home there was water, but not a lot...maybe 4-6 cups worth. I forgot to pull the plug when I got out of the water so I know that no water drained on the way home. I did not use the bilge pump while out either because I checked the bilge area a few times and it was dry. I do not have an automatic bilge. It's an old boat.

I am hoping that the bellow slipped off as I tilted the motor for trailering. This would account for the relatively small amount of water in the bilge. We were not sitting in the water long after I tilted the motor and pulled her out.

Othewise, I agree... we could of sunk. I think I got lucky. We were out for hours water skiing and floating around. I would think that if the bellow was off when we entered the water, we would have had problems.

I spoke to my mechanic an he's going to pull the drive and inspect the gimbal and U-joints. Hopefully I caught this early enough so no major damage is done. I am also glad my boat is not at the bottom of the lake.

I am going to check my clamps before every outing from now on. Seems pretty easy to do when tilting the drive up for the trip to the lake.

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

larry1167 said:

Is it somewhat typical for the bellow to work itself free, or did my old mechanic not tighten the clamp enough?

Click to expand...

No it's not typical, and it should not have happened. I suspect who ever worked on it last did not properly install that belows...

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

Sorry, but I can't imagine either bellows on a Cobra drive just coming loose. Neither is held on with a hose clamp.

Look at this picture, which bellows has water in it, 19 or 21? We can go from their.

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

Unfortunately guys it's definitely 19. I can see the u-joint and even the zerk fitting now that the bellow is not attached. The hose clamp failed (#20). It appears the clamp was the only thing holding the bellow on. It must not have been tight enough.

What else should be holding the bellow in addition to #20?

I had my old mechanic replace the bellows two years ago during normal drive maintenance. He is my old mechanic because he also replaced the drive fluid during this visit. He returned the boat to me with half the required fluid in the drive. I checked the dip stick before I went out and noticed it was low. It ended up being 1 quart low. I assumed he filled from the dip stick instead of the fill plug and it had an air bubble. Or he had his son do it and he didn't know what he was doing. Now this.

If I am lucky and the bellow just slipped off during my last trip, could the u-joints be okay if they are not rusty and pass inspection with the drive off? We could re-grease the zerks and maybe be on our way? I am thinking about replacing the gimbal bearing regardless even if it spins well. Trying to save some money if the u-joints look good.

Let me know what you guys think and thanks for the input.

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

Deleted

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

If it came loose, it wasn't installed properly, the bellows needs to fit over a rib in the bellhousing (aka pivot housing #14 in the pic) and is held in place by the drive when installed.
If the drive is filled from the bottom, it may only take 1/2 the gear lube it needs because it was filled improperly and has a big air bubble.

Sorry, but you may need to find a mechanic that speaks fluent OMC Cobra, obviously yours doesn't.

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

Thanks Don. I fired my old mechanic years ago after the oil mistake. That could have cost me a complete new drive. I have a new mechanic and he speaks Cobra.

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

Guess it's time to fix the problems you have now, and move on.

You really need to get the OEM Service manuals, and if nothing else read and know what you need to do, along with what and when it needs done, and basically to keep it working correctly and not get stuck between a rock and a hard spot again.

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

Agree on the point that you need a good OMC mechanic, they are not easy to find, which is one of the main problems in owning one of these. I also had a water in the gear oil problem, it turned out to be a combination of the water pump shaft seal and the bearing retainer, and once that was fixed there has not been any water in the gear oil for the past 4 seasons...
I also had the same guy adjust the shift linkage back in 2004 and the drive has shifted great since then, all I have done each year is remove the drive, clean out the pocket in the pivot housing by the shift bellcrank, grease all the pivot points, and make sure the engine runs smooth enough to idle at 550 rpm in gear....

Oh and even though most people don't do this, replace the plastic sealing washers each time you change the drive oil....they do take a set from the little ridge in the drain and fill screws...

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

Lou- where do you purchase the plastic washers? Do you just get them from the hardware store or do you special order them from a marine store?

Don- I have OEM service manual. I do most of the maintenance myself (oil changes, winterization, tuning the engine, etc), but take the boat to my mechanic for big ticket items. I know my limits. I removed the drive years ago to replace the engine, but don't feel like doing it again. It's tempting, however, because when I put the bellows back on they never came off and I never had any issues with the drive.

Having an OMC drive is a bummer, but the Cobra has been pretty durable and I put it through it's paces towing my fat friends on slalom skiis and towing my kids for hours on end. It's held up really well. I also like the fact that I can replace the impeller without removing the drive.

Taking the boat in later this week to have the drive inspected. I hope I caught the issue early enough.

Re: OMC Cobra Drive-milky oil - UPDATE (not good)

larry1167 said:

Lou- where do you purchase the plastic washers? Do you just get them from the hardware store or do you special order them from a marine store?



Having an OMC drive is a bummer, but the Cobra has been pretty durable and I put it through it's paces towing my fat friends on slalom skiis and towing my kids for hours on end. It's held up really well. I also like the fact that I can replace the impeller without removing the drive.

Click to expand...

If you have an Evinrude dealer local to you, the can get em for you, also on line retailers like dougrussell.com also have them. I get em locally at my shop (ex-OMC shop) and they can order any available Cobra parts, but since they still service a few Cobras they keep stuff in stock....

Is this the first season you had water in the gear oil? If so then I wouldn't worry too much, just make sure they do a pressure and vaccum test on it and use new plastic gaskets when you do the gear oil. I use the Merc Hi Performance gear oil in my Cobra (mechanic's recommendation) and it works well with that. Very little wear particles on the magnet and good shifting, little to no gear noise....