A gear is a cogwheel or a rotating machine part, which has cut teeth or cogs that mesh with the other toothed part to transmit torque. Gear oil is a lubricant made specifically for transmissions, transfer cases, and differentials in automobiles, heavy vehicles, aircraft, ships, boats, and other industrial machinery. Gearboxes are expected to perform under conditions of high heat, high pressure, heavy loads, and in environments contaminated with process debris, chemicals, water, and dirt. This may cause gears to wear off prematurely resulting in machine downtime.