Would You Rather? Finding an Easy Answer to the Gearbox Layup Game

November 12, 2025

Gearbox Layup - Cortec Corporation Would you rather add 10 gallons (38 L) of oil or 0.3 gallons (1 L) of M-535 HV to a large gearbox for layup? The answer is easy when you look at the benefits of Cortec^®oil additives for your wallet and the environment!

Traditional Method of Gearbox Layup

The most common practice for gearbox layup is as follows:
1. Fill the gearbox case with oil, leaving one inch (2.54 cm) to spare at the top.
2. Plug all openings.
3. Apply a dry film corrosion inhibitor to external shafts.
4. Apply grease where needed.
5. Rotate shafts and inspect once a month.
6. Drain excess oil to operational level at startup.

The biggest problem with this method is the large amount of oil that is required, especially for giant gearboxes used in mining, marine, and wind power industries that call for hundreds or thousands of additional gallons of oil. This is not only expensive but generates excessive hazardous waste. In addition, the headspace above the gearbox oil (the most vulnerable to condensation corrosion) is inadequately protected. Oil leakage is also a higher risk in some cases.

A Better Approach to Gearbox Layup

Using a Cortec^® gearbox oil additive can significantly reduce the amount of oil wasted while lowering costs and enhancing protection. The basic steps could look like this:
1. Add M-535 HV or M-531 (be sure to check compatibility) to oil at 3% of operating volume and circulate for five minutes.
2. Plug all openings.
3. Apply VpCI^®-368 to external shafts.
4. Apply grease where needed.
5. Rotate shafts and inspect once a month.
6. Drain and flush the system before adding the standard amount of fresh operating oil at startup.

In addition to generating lower costs and less hazardous waste, these two Cortec^® additives contain Vapor phase Corrosion Inhibitors, allowing them to offer corrosion protection below and above the oil level. If you need to shut down your gearbox for six months or more, be sure to weigh the options in terms of cost and hazardous waste. The larger the gearbox, the greater the reduction in costs and hazardous waste by using a Cortec^® additive. Contact Cortec^® for specific advice on improving your gearbox layup!

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