Omc cobra gear case oil. Water or just suds?

[Jeremy S]

1. I have a 1988 wellcraft with an Omc 4.3 *and a cobra outdrive. I'm learning as I go , but I have seen oil and water mixed but I can't tell if mine is mixing water or, am I just looking at agitated gear oil? I have acouple pics I hope someone can help.*

2. Also when I bought my boat the "do not remove drain plug" that was suppose to be under a sticker was all ready gone, does anyone know a part # or what else I could use to replace it? When I had the outdrive off the nut was all ready gone. And could that plug cause an air bubble that messes up my cooling system? When I got it on the water it wouldn't pull water into the engine but my impellor didn't burn up.

 

[jerryjerry05]

Re: Omc cobra gear case oil. Water or just suds?

The oil is bubbly.It's from turning in the gears.There's a dipstick on the top so you don't have to remove the cover.I think the tourqe is 20# on those bolts.
The hole will let air in and stop the pump from working.
Once the boat is on plane that portion of the drive is no longer out of the water.
Unfortunatly they don't list those parts as they thought if they covered them with a sticker no one would find them and mess with them.
Look on the net.Key in OMC Cobra parts and lots of places come up.
Someone will have a replacement.
Untill then silicone and duct tape.J

 

[HT32BSX115]

Re: Omc cobra gear case oil. Water or just suds?

The hole will let air in and stop the pump from working.
Once the boat is on plane that portion of the drive is no longer out of the water.

ah,

Actually, that hole is the discharge area of the raw water pump. the water from there goes to the fitting on the transom mount that is connected to supply hose/tube that goes through the transom as indicated below.


The small hole in the transom gasket is lined up with that area in the drive. The water from there goes into the fitting and hoses, #19, 18, 37, 68 and then on to the PS cooler, oil cooler, T-stat housing or heat exchanger(if installed).

It'll be water under pressure so if the boat is on plane, you'll probably see water shooting out of the hole if it's uncovered.

Of course, that'll mean that you won't be getting the full amount of flow through the engine and manifolds/risers either.....



Regards,


Rick

btw, The oil does look like it *may* have water in it.


You should drain it and refill. (FOLLOW THE OMC COBRA PROCEDURE!!......drain from drain port, fill from "FILL" port etc etc....!!!)

Run it and then check it for water intrusion......

 

[Jeremy S]

Re: Omc cobra gear case oil. Water or just suds?

Thanks for the input. I'm learning as I go. I drained the gearcase shortly after I took the pics but before I posted my questions, then I second guessed myself and thought I would ask.

I will refill the gearcase through the upper fill hole on lower unit, as I have read that any other way will junk my gear set.

I will look for a plug for that and plug it somehow.

Thanks again
Jeremy S

 

[HT32BSX115]

Re: Omc cobra gear case oil. Water or just suds?

There's more on that too.

ENSURE that the drive is level, fill it through the FILL port until it shows "FULL" on the dipstick when "resting" on the top of the threads. (I.E. NOT screwed in), This will allow for a "slight over-fill"



Then run the drive a little, let it sit for a while. (to allow any large bubbles to float to the top......) subsequent oil level checks are then conducted with the dipstick screwed all the way in.


Use a good quality oil. Mercury HP gear Lube , Volvo and/or Mobil1 synthetic or any other marine type gear oil is good.


Once you're satisfied that the drive is full of oil, run it around the lake long enough to warm it up. Then let it cool down while the drive is still in the water. If there's a leak, you'll probably notice water in the drive after it cools down.

After it cools down you can remove the drain plug and inspect for water.....


Cheers,


Rick

 

[Lou C]

Re: Omc cobra gear case oil. Water or just suds?

Thanks for the input. I'm learning as I go. I drained the gearcase shortly after I took the pics but before I posted my questions, then I second guessed myself and thought I would ask.

I will refill the gearcase through the upper fill hole on lower unit, as I have read that any other way will junk my gear set.

I will look for a plug for that and plug it somehow.

Thanks again
Jeremy S

if you look at the parts diagrams for the later versions of the Cobra, they do list the parts, look here

http://www.dougrussell.com/partscat...,1063,1064,1065,1066,1067,1068,1069,1070,1071


you need parts 9--14, plus the medallion is part 58...

Even though they show these parts on the starboard side, there is really no hole on the starboard side, they are for the port side, if you can get the parts, install them with some thread locker on the threads and OMC gasket sealer on the piece that seals against the hole in the drive.

I don't know why they did not list these parts in the diagrams for the earlier years, but the upper gear housings up to 93 are all the same so no worries it will fit....

 

[MRS]

Re: Omc cobra gear case oil. Water or just suds?

If you drain it you need 64oz. back in it. Then it is full.

 

[Lou C]

Re: Omc cobra gear case oil. Water or just suds?

And I've been changing it the OMC way for the 8 years I've owned it, as described by Rick above, NEVER had a problem, make sure you get 64 (if a regular dog clutch model) in it, and let it sit, then check it again, to make sure. I use the Mercury High Performance Gear lube, it works fine in a Cobra and is easy to find. To check for water in the gear oil, drain it into a clean container and pour some in a clear glass jar like a clean mayonnaise jar and let it sit, if there is water it will look milky on the bottom. If there's a lot of water it will be pretty obvious, milky coffee colored plumes in the gear oil. Change those plastic washer gaskets each season to be on the safe side.

 

[HT32BSX115]

Re: Omc cobra gear case oil. Water or just suds?

Even though they show these parts on the starboard side, there is really no hole on the starboard side, they are for the port side,

It's strange that they show it on the "wrong" side!!! Almost like the original microfiche was scanned "backwards"!

 

[Jeremy S]

Re: Omc cobra gear case oil. Water or just suds?

Thanks for all your help. This forum rules. Gonna order my parts, pull the outdrive re-seal the whole thing from bottom to top and go boating!

Thanks AGAIN!!!
Jeremy S.