Gear oil

[labguy3232]

Hey guys. Just finished the process of removing broken starter mounting bolts from my 86 3.0L OMC. Thanks for the help in removing outdrive/engine. Next question....How much gear oil should there be in the outdrive? When I removed the dipstick from the top of the outdrive, there are no markings on the dipstick to indicate appropriate levels as on an oil dipstick. Also, what kind of oil should I use? THanks, Don

 

[fourwinnsdook]

Re: Gear oil

I was told by a mechanic that any heavy gear oil would work, i think i used 90W but it was marine gear oil. my 4.3 held a little over 2 quarts i believe. if it's low you might as well drain it and refill it. make sure you fill from the bottom to prevent air bubbles.

 

[labguy3232]

Re: Gear oil

Thanks. To be on the safe side, I will just drain and refill. Next question....do you know where the drain plug is located on the cobra outdrive? I assume on the bottom but there are several bolts down there. When you say fill from the bottom first, is there another place that it should be filled from. THanks in advance for the info. Don

 

[HT32BSX115]

Re: Gear oil

Howdy Don,


DO NOT FILL FROM THE BOTTOM!!!!!! That will trap a bubble at the top


You WILL destroy the upper gears and bearings which will trash the rest of it.


A Cobra is drained from the bottom plug.....There's only one on the bottom.

It is filled at the "FILL" plug about halfway up.


Here's the instructions directly from the service manual:

1. Remove the oil drain plug (starboard side of lower gearcase) and the oil level dipstick (top of vertical drive)

2. After vertical drive has drained completely, securely replace the oil drain plug.

3. Remove oil fill plug (Starboard side of vertical drive ) [it's towards the front near the cavitation plate]

4. Fill vertical drive with OMC Hi-Vis gearcase lubricant through the oil fill plug location. The vertical drive is properly filled when the oil level appears on the mark on the oil dipstick. Check oil level with the dipstick cap resting on the top of the hole.

NOTE When completely changing the lubricant in the vertical drive, the oil level must be checked with the dipstick cap resting on top of the hole. This will provide a slight overfill to allow for an oil drop caused by trapped air being purged when running the drive. All subsequent checks are made with the dipstick fully threaded into hole.

5. Securely replace the dipstick before removing the filler from the gearcase. This will create an airlock and will hold the oil in the drive unit until the oil fill plug can be securely replaced.







I believe your owners manual may indicate how to fill it. Go to Walmart and get some Mobil 1 Gear oil. Or use Mercury HP (syn) gear oil.


Cobras hold from 1.8L (About 2qt) for the 2.3/3.0 to 3.2L (almost 4qt) of oil for the 7.5L model.

Yours should hold 1.8l (60 oz)


If you do not have a service manual, now would be a good time to get one.






Regards,


Rick



People.......NEVER fill a cobra from the bottom!!

Thanks. To be on the safe side, I will just drain and refill. Next question....do you know where the drain plug is located on the cobra outdrive? I assume on the bottom but there are several bolts down there. When you say fill from the bottom first, is there another place that it should be filled from. THanks in advance for the info. Don

 

[fourwinnsdook]

Re: Gear oil

I read on another forum to fill it from the bottom till it starts comming out of the middle hole, then fill it from the middle up. That's how i did it. I've checked it numerous times since then and all is still full. Maybe i got lucky, but my father has had numerous omc's and has done it the same way.

 

[HT32BSX115]

Re: Gear oil

Forums of course, are not "sources" of information. Having said that, you may be "OK" filling it that way........Since your filling it from the fill port when the level gets to it......

But.....That's not what you said....you said to fill it from the bottom........
The service manual is VERY specific.......

I have a King Cobra drive laying on a pallet that is the third replacement drive that was on my FourWinns. The first 2 drives were filled incorrectly by dealers/"professionals" that filled them like Mercs.....both only made it about halfway around the lake before freezing up.

When I changed the drive oil, I followed the manual procedure EXACTLY every time.

That's all I can suggest.



Regards,




Rick

I read on another forum to fill it from the bottom till it starts comming out of the middle hole, then fill it from the middle up. That's how i did it. I've checked it numerous times since then and all is still full. Maybe i got lucky, but my father has had numerous omc's and has done it the same way.

 

[fourwinnsdook]

Re: Gear oil

Oh, i agree 100% to follow the manual completely.