Expert Knowledge

What should I do if my industrial gear oil looks milky or hazy?

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:

1. Ensure the lubricant fill level is correct.
2. Ensure the lubricant viscosity is correct, not too heavy.
3. If a lubricant circulating system is in use, ensure that all suction side fittings are airtight. Test for air leaks in a lube circulating system by using shaving cream or similar material. Spread it on the pipe connections and look for holes being sucked into the foam.
4. Ensure that all free water has been drained from the reservoir tank or use water removal filtration if the equipment cannot be taken out of service.