Filling lower unit oil

[bheston]

I have a 3.0L OMC and changed the lower unit oil. Everyone says to fill from the bottom, which I assume they mean the drain plug. So the lower unit has a drain plug clear on the bottom, fill hole around the middle side of the unit (towards the top of the lower half of the unit that is) and the dipstick/cap right on the top of the unit.

The manual says to pump oil in the fill hole (middle) until the dipstick reads correctly (top). I thought I would fill it up to the fill hole, but then nothing is up on the dipstick/cap on the top of the unit. Do I pump oil in PAST the fill hole in the middle until it gets up to the dipstick?

The manual isn't very clear on this, thanks for the help!

 

[ne7800]

Re: Filling lower unit oil

yes keep filling it till it reaches the dipstick

 

[Gary H NC]

Re: Filling lower unit oil

Fill it until it reads full on the dipstick with it just resting on the threads...not screwed in.
Fill SLOW..Cobra drives can have air pockets and you can trash the drive.

After filling do a test run and check the level again.

 

[mthieme]

Re: Filling lower unit oil

Fill it until it reads full on the dipstick with it just resting on the threads...not screwed in.
Fill SLOW..Cobra drives can have air pockets and you can trash the drive.

...which is why you want to fill it from the bottom.

 

[Chris Hays]

Re: Filling lower unit oil

Fill it from the drain plug up to the top.

 

[Don S]

Re: Filling lower unit oil

Are you trying to fill a Cobra drive or a stringer drive. Makes a HUGE difference. And they are both run with a 3.0L/140 engine, what every you want to call it.

 

[Gary H NC]

Re: Filling lower unit oil

Good point Don....
I was going on the assumption it was a Cobra..

 

[Don S]

Re: Filling lower unit oil

Well Gary, ever notice what happens to me when I assume something from a post (like what kind of drive). You can bet your pay check that I am wrong.
Hmmmmmm. I should be able to make a lot of money off that ability ........................... I assume it would HAVE to work!

 

[HT32BSX115]

Re: Filling lower unit oil

I have a 3.0L OMC and changed the lower unit oil. Everyone says to fill from the bottom, which I assume they mean the drain plug. So the lower unit has a drain plug clear on the bottom, fill hole around the middle side of the unit (towards the top of the lower half of the unit that is) and the dipstick/cap right on the top of the unit.

The manual says to pump oil in the fill hole (middle) until the dipstick reads correctly (top). I thought I would fill it up to the fill hole, but then nothing is up on the dipstick/cap on the top of the unit. Do I pump oil in PAST the fill hole in the middle until it gets up to the dipstick?

The manual isn't very clear on this, thanks for the help!

You know it's pretty important that you indicate just exactly what you have. I have a King Cobra drive that was replaced by a Four Winns dealer because the moron that was working there didn't bother to read the manual and filled it like a Mercruiser.


It sounds a lot like you have a Cobra.


You fill it exactly like it says in the manual. (If it's an OMC Manual)

If it IS a Cobra, Fill it from the middle "FILL" hole ( in accordance with the OMC manual) . DO NOT FILL IT FROM THE BOTTOM.

Just follow the instructions in the (OEM OMC) manual. Leave the dipstick resting on the top and fill it from the fill port until it indicates full. (which will cause a slight over fill) Then run it to release any small pockets of air. Subsequent checks are done with the dipstick screwed all the way in.


Regards,


Rick

 

[Gary H NC]

Re: Filling lower unit oil

Well Gary, ever notice what happens to me when I assume something from a post (like what kind of drive). You can bet your pay check that I am wrong.
Hmmmmmm. I should be able to make a lot of money off that ability ........................... I assume it would HAVE to work!

LOL! I know what you are saying Don,
When he said it had the dipstick plug on the top i thought Cobra.
I have never owned a stringer drive..(thank goodness)..

 

[chiefalen]

Re: Filling lower unit oil

What year is it? Does it have a half moon gear on the drive or rams?

 

[HT32BSX115]

Re: Filling lower unit oil

Ok,

This is a test, right?

I have read thru this thread a couple of times and I cannot see the model or year anywhere. I got that it's an OMC.... discussion of the "fill" port vs "drain" port implies it's a Cobra.....and should I assume that a Stringer doesn't have a "fill" port? (But a wise man once said, watch what you assume.....assumptions are frequently wrong)

So, what exactly are we talking about?

 

[Gary H NC]

Re: Filling lower unit oil

Since the original poster never responded its just a guess...

Even Don's crystal ball does not help...

 

[HT32BSX115]

Re: Filling lower unit oil

Since the original poster never responded its just a guess...

Even Don's crystal ball does not help...

I thought he broke that thing?

 

[bheston]

Re: Filling lower unit oil

Sorry for the late response guys, it is a 1987 and yes it is a Cobra. I think you have answered my questions, and thank you for the great responses!

So I guess this will just be a messy procedure since you will spill some oil out of the fill hole from the time you pull the fill tube until you can get the plug back in place, since the oil is filled above the fill hole. I suppose this has to do with getting as much of the air pockets out as possible.

Thanks again!
Bob

 

[HT32BSX115]

Re: Filling lower unit oil

Bob,

it's really easy to do. And you won't spill much.

After draining, put the drain plug back in and remove the fill plug.

Connect the pump (use a threaded fill "tube") to the fill port.

Leave the dipstick resting on the threads on top. pump oil in until it indicates full on the dipstick.

When full, tighten the dipstick and then remove the fill tube. (you won't lose very much at all because once the caps are all tight, it's a closed system)

Run it a little and check frequently once it's warmed up. (Use a good synthetic gear lube like Mercury HP gear lube.....bubbles don't last long in warm synthetic oil)

After you run it enough to clear out all the bubbles, top it off from the dipstick hole. (check level then with the dipstick screwed all the way in)

When you fill it up you'll you're close to the right amount when you get 60oz or 1774ml of oil in it. ( 32oz = 1 qt.)

According to my 1987 OMC Cobra service manual (#507605) , you should change the oil twice per season or every 50 hrs.

If you don't have that manual and you want to do your own maintenance it would be a good idea to get one. The Seloc and Clymer manuals are not that great.

Regards,


Rick