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Proper Drive Lube Color

wish2fish

Regular Contributor
Does High Performance gear lube lighten somewhat in color after running?

I drained and replace the lube while changing the water pump. I went back and check the lube and it looked a little lighter in color, but it wasn't frothy. Does air get mixed in with the lube when running, because that is what I thought it looked like.

thanks,
 
As long as the oil is translucent and not milky there isn't a leak. Air is purged from the lower drive when it is filled from the bottom. If you don't have an OD oil reservior then there is a small amount of room w/air in the top of the OD for oil expansion.
 
Sorry I forgot to list what the drive was. It is a 1981 mercruiser I-drive so it does not have a reservoir.

There wasn't much time for the air settle as soon as it was filled we put it on the hose to run.
 
High performance gear lube is PURPLE/GREEN and should only get black over time.

If it is airated then it will look a slightly lighter green.

If you suspect water, have the drive pressure checked and know for sure.
 
Does High Performance gear lube lighten somewhat in color after running?

I drained and replace the lube while changing the water pump. I went back and check the lube and it looked a little lighter in color, but it wasn't frothy. Does air get mixed in with the lube when running, because that is what I thought it looked like.

thanks,

the lube normally darkens as time passes. the lighter color may mean mositure .. remove the top cap of drive see if it has mositure droplets..
make a test guage for your drive using a pump bottle adapter . install in the upper vent port , the air pressure I use is 10 psi approx and if it holds for a few hours its good..this should be done every season to protect the drive from water ..
 
Jcat,

Just an FYI

Although I have never seen a merc spec for pressure checking a outdrive this is what I KNOW!

The outdrive (alpha 1 gen 1 and Gen II) produce ~ 7-9 psi.

OMC use to publish a spec of pressure checking there omc cobra and king cobra outdrive to 18 psi. Not a whole lot of differences in the basic deign so it was felt that that spec - 3 psi would be a good test pressure for mercury outdrives.

So I reccomend 15 psi for a outdrive (pressure check) and it should hold for 2-3 minutes with no needle movement.
Also this check should be done with NO oil in drive, either vent or drain hole can be used.

Also if no oil is missing/leaking but water is getting in then a vaccuum test must be performed with a vacuum pump tester that looks identical to the pressure checker sold by STEVENS Instruments. They are what I have and use.
 
Jcat,

Just an FYI

Although I have never seen a merc spec for pressure checking a outdrive this is what I KNOW!

The outdrive (alpha 1 gen 1 and Gen II) produce ~ 7-9 psi.

OMC use to publish a spec of pressure checking there omc cobra and king cobra outdrive to 18 psi. Not a whole lot of differences in the basic deign so it was felt that that spec - 3 psi would be a good test pressure for mercury outdrives.

So I reccomend 15 psi for a outdrive (pressure check) and it should hold for 2-3 minutes with no needle movement.
Also this check should be done with NO oil in drive, either vent or drain hole can be used.

Also if no oil is missing/leaking but water is getting in then a vaccuum test must be performed with a vacuum pump tester that looks identical to the pressure checker sold by STEVENS Instruments. They are what I have and use.

thanks for that info . sounds good..

I don't like the vacuum test . the O ring on the alpha 1 between the upper/lower might get sucked in ..no retainer for vacuum on inside diameter of it. since I keep the pressure on it for a long time so far its working great.. I had the usual leaks over the years ...
 
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