Proper OMC Cobra drive lube fill????

[larrythorson]

I have asked several OMC guru's a few mechanics and the one i personally found that has been doing this 35 years said the proper way to fill a Cobra is different from what others are telling me.
I was told to fill thru the very bottom, once the fluid was running out the mid point hole place screw back in hole and continue to pump up to fill upper case until its between the lines on the stick. ANYONE care to add comments, suggestions or knowledge????

 

[bruceb58]

That is wrong and you will wipe out your drive.

After you drain your drive, you put the drain plug back in and then fill from the middle until it comes out the top.

This is from the factory manual:

 

[bruceb58]

Also, always replace the gaskets/o-rings on the 3 plugs every time you change your lube.

 

[Sparkinator]

What year is your Cobra?

 

[bruceb58]

What year is your Cobra?

His other thread says 1986.

 

[Lou C]

I've been doing it the OMC book way 13 years worth and never had a problem . I don't know why some people think they know more than the engineers who built it did. Follow the book procedure above use new gaskets and enjoy a long life for the drive . No need to experiment.

 

[Sparkinator]

His other thread says 1986.

Thanks Bruce.

I'll kindly but out. :lol:

 

[larrythorson]

The reason why I asked is the outfit in Michigan specifically said they had to be filled from the bottom and now Im on my 2nd drive that has smoked Volvo synthetic black and dumped what was in the top gear case out thru the seal after what I am now guessing is the air pocket worked its self out after a short run time, the oil level dropped, heated the gear case up from improper lubrication and built up pressure and pushed what was being slung out the top drive shaft seal into the billows. The first time i caught it after 3 hours of run time and this time it happened after a half hour run time and no more than 1/4 throttle for 10 minutes. and both were filled from the bottom!!!!!!!!

 

[bruceb58]

Well, they are wrong. You would think that someone who rebuilds them would know the correct way.

No matter which way you fill them, Its always a good idea to check it again the next day.

I have a Volvo now but used to have a Cobra. I always check my gear oil the night before I take it out. As you know, they are VERY expensive. Probably more expensive than the rest of the boat.

 

[larrythorson]

Sadly Bruce I have never had the opportunity to change my own gear case lube yet the unit went to shat before I could. The initial drive unit i got from all American Outdrive lasted 13 hours, I had the oil changed at 10 hours per my agreement with them and it was to be refilled with Volvo Synthetic. When I went to pick it up from my local BRP the mechanic said the oil was kinda dark for a new unit, I called the outfit I got it from and they said that was to be expected due to run in wear ( I know that should have been a first RED FLAG) I ran it for 3 hours after the lube change and coming to in to the dock i smelled something HORRIBLE almost like hot Asphalt. It was the upper gear case front seal puking into the billow!!!! I took it back to Michigan and when he tore it down the first place he looked was not the gear case but the clutch dogs. When it was found that the clutch dogs still looked new he changed his tone and began blaming the dealer for not properly filling it, as it was filled right by the instructions that was given to me by the rebuilder as I watched him do it in the shop. I had to go pick the unit up again in Michigan and had it set again on my first trip out I ran 3 miles at less than the speedo would register about 2 miles at little less than half throttle and the final 3 at little more than idle just cruising and it didnt seem right but I somewhat attribute that to being paranoid. When i pulled it out and got it back home I pulled the stick on the top of the case there was one dab of BLACK lube, I wiped it and checked it again NOTHING!!!! I pulled the top cover off of the case and there was just enough oil to cover 1/2 the gears on the upper shaft and gear set in the case and it was again smoked black in 30-45 minutes run time!!!! Back it went for the 3rd time to get rebuilt I am now being told that its my fresh water circulation system, I have a bad thermostat, Bad water pump on the block I say Bull****!!! I have never had the motor get over 160-170, I took the inlet side off of the power steering ran the engine 15 minutes and it was a rock solid 160* I then ran the water back out thru the pick up thru the inside of the transoms and no obstructions!!! I am a sharp mechanic when it come to most everything from Bikes to Snowmobiles to cars and trucks and from what I see from the the thermostat housing even if the thermostat was stuck closed and the water pump on the block was completely shot that water from the drive would route right back thru the exhaust manifolds and back out not creating any restricticton for the water pump on the drive to complete this line this yahoo is trying to feed me> Any suggestions comments or opinions are greatly appreciated!!!

 

[bruceb58]

Did you happen to check the level when you got it back from the dealer either time?

Like I said, fill it the proper way and recheck many hours later.

BTW, you aren't the first person on here that had an OMC Cobra die from filling from the bottom.

 

[larrythorson]

Yes both times prior to putting it I checked it and it was where it should be but mind you neither time had the unit been under engine power after being refilled. I am learning as I go on this now. I have to dig in and fight it out with this guy that HE is the one who gave me improper filling procedures and improperly filled the case the last time. I have almost 3500$ wrapped up in this nightmare and what I need now is someone who has the experience to back me up that he indeed is filling these wrong. I wondered if OMC or BRP has any service bulletins as to proper case fill on these units. I also had spoke to a gentleman from Kankakee Illinois who had been to the OMC Service school in Waukegan and he said from midpoint... im so POed right now!

 

[HT32BSX115]

Yes both times prior to putting it I checked it and it was where it should be but mind you neither time had the unit been under engine power after being refilled. I am learning as I go on this now. I have to dig in and fight it out with this guy that HE is the one who gave me improper filling procedures and improperly filled the case the last time. I have almost 3500$ wrapped up in this nightmare and what I need now is someone who has the experience to back me up that he indeed is filling these wrong. I wondered if OMC or BRP has any service bulletins as to proper case fill on these units. I also had spoke to a gentleman from Kankakee Illinois who had been to the OMC Service school in Waukegan and he said from midpoint... im so POed right now!

Howdy,

Sorry to see you got snookered by another "expert"!

My previous Dog-clutch King Cobra when owned by my brother was filled the "Mercruiser" way twice by 2 different "dealers" before I got it. BOTH times the dealer stepped up and replaced the drive. (after my brother threatened "lawyering -up")

Many of those "Professional mechanics" fill the Cobra from the bottom (drain) UNTIL fluid comes out the (correct) fill port, THEN they continue filling from the recommended FILL port until full.

While that does seem to work, some people just forget to continue filling from the fill port or never really get the picture the picture at all.........

There are threads here on iBoats where people swear up and down that the above method works well and their "Pet Mechanic" does it all the time etc etc.............

Problem is, it traps a big bubble that once migrated to the "top", where the upper gears are they uncover and quickly overheat! You know the rest..............

Another thing is that some people think you can then get away with just replacing the "upper".

You can, but only after completely disassembling the lower and carefully inspecting/flushing/cleaning etc.......(the upper and lower share the same metal contaminated oil)

Bottom line of course is to follow the OEM service manual procedure. (period) Don't use a Seloc or Clymer manual....(except maybe to use as a knee pad or fire starter!

Sorry you had to find out the "hard way"


Rick


by the way.........

also had spoke to a gentleman from Kankakee Illinois who had been to the OMC Service school in Waukegan and he said from midpoint... im so POed right now!

Either the other "mechanics were asleep when they covered Cobra filling procedures, or they have Dementia that guy is absolutely right!

 

[Lou C]

The other point is that each drive(4 cyl, V6/8 and the 460 King all take different amounts of gear oil) holds a specific quantity of fluid. If you don't get the whole amount in when it reads full, that means there is an air bubble and you need to pump slower and wait a bit to let the level equalize. This is also why the official instructions tell you not to screw in the top dip stick and just let it sit in the hole. It helps allow air bubbles to escape.

 

[HT32BSX115]

The other point is that each drive(4 cyl, V6/8 and the 460 King all take different amounts of gear oil) holds a specific quantity of fluid. If you don't get the whole amount in when it reads full, that means there is an air bubble and you need to pump slower and wait a bit to let the level equalize. This is also why the official instructions tell you not to screw in the top dip stick and just let it sit in the hole. It helps allow air bubbles to escape.

My manual said to fill to "FULL" with the dipstick sitting on the threads to "allow for a for a slight overfill" THEN do subsequent checks with the dipstick screwed all the way in............

It's still strange that some still keep wanting to do the entire process different than what the OEM manual suggests....................

 

[larrythorson]

Yes I am learning the hard way and I have gotten an overwhelming amount of ammo to go back after this guy, I dont think it intentional i think its ignorance!!!!!!