OMC gear oil change!

[MOP]

Since gear oil is being talked about, OMC must be done differently than all others! They get drained the same way at the bottom, but must be filled using the fill plug located by the Cavitation plate. If you mistakenly fill from the bottom it will air lock but show a full reading, when you run it the air lock breaks the oil level drops and the upper will burn the gear set. And like the other post Merc HP oil is the way to go, deeper pockets can refill with Red Line.

MOP

[BUIZILLA]

MOP, my local OMC guy did it your way on my Cobra drive, so I paid him for the service, perfect condition drive with less than 75 original hours on it.... $1600 later he was wrong, burned it up, locked up, with 1 mile..... The OMC factory told me to fill it from the lowest hole with BOTH the middle and upper plug removed. When the level gets to the middle plug, insert it, then continue to pump to the top, using the upper dipstick as a final reference. Needless to say, mech #1 got an a$$ chewing from me, and he refused to pay for any parts or labor whatsoever....

J

[MOP]

MOP, my local OMC guy did it your way on my Cobra drive, so I paid him for the service, perfect condition drive with less than 75 original hours on it.... $1600 later he was wrong, burned it up, locked up, with 1 mile..... The OMC factory told me to fill it from the lowest hole with BOTH the middle and upper plug removed. When the level gets to the middle plug, insert it, then continue to pump to the top, using the upper dipstick as a final reference. Needless to say, mech #1 got an a$$ chewing from me, and he refused to pay for any parts or labor whatsoever....

J

Jim we have been doing it the book way since the Cobras came out with only one failure that was filled from the bottom by a newly hired Merc mech no ass chewing he did not know. I need to refill mine for the new buyer and will try the two plug thing it sounds like it is even better, the manual has a big note to also fill slowly to prevent air locks. With that plug out that probably ends the problem. Thanks for the tip, I will pass it on to the shop guys.

Phil

[Brad Lyon]

I tried to change my OMC Cobra outdrive oil today. This is my first attempt. Am I in trouble? I have three questions/comments. First, it took forever to all drain out. Second, I can only find 2 plugs for the lower unit, one just below the cavitation plate and one at the very bottom of the outdrive. Third, it only took one quart to fill it back up. The instructions said after the oil comes out the top hole start the engine and put it in gear for brief moment then check to see if you can add more oil. It did not take any more oil, should it?

Brad

[Brad Lyon]

Thanks for the response Madpoodle. I just went out and inspected my outdrive. I do not have any plugs on the port side of the lower unit, just the two on the starboard side (at the skeg and at the cavitation plate). On the upper unit there is two plugs on each side of the outdrive that look just like the plugs on the lower unit. There is also a plug on the very top of the outdrive, not on a side but on the top. Does this outdrive just have one oil cavity for both the upper and lower units?

[Brad Lyon]

Yep, the one on the very top is a dip stick. Funny that is how I feel right now. Thanks for your help, looks like I get to start all over and do it again tomorrow. It's a good thing I bought extra oil.

Brad