It’s unusual for industrial gear oil to have a milky appearance because it has good water separation properties. Free water should be settling down to the bottom of the reservoir tank, which can easily be drained out.
However, it is possible for water to contaminate a gear box. If the machine has not been operated for a long time, it is possible for moisture in the air to condense and contaminate the gear oil. Alternatively, the mechanical agitation of the lubricant and water combination from the gears can whip the oil into a froth.
If you are experiencing a milky gear oil, it is recommended that you do not run the machine until you inspect the equipment and lubricant because it may result in pump and gear damage.
We recommend the following: