Lubrication Strategies for Different Size Gearboxes

GEARBOX MAINTENANCE FREQUENCY

Lubrication maintenance practices for large, heavy-duty gearboxes and smaller industrial gearboxes can vary significantly depending on the specific application and operating conditions. Accordingly, gearbox manufacturers recommend the type of gear oil for each application based on speed, load, temperature and gear type.  

Always follow the manufacturer’s gear oil recommendations. Every gearbox should have a tag that indicates the type and viscosity of gear oil required for that specific gearbox and its level of service. Tags may name a specific gear oil or include industry standards, such as ISO viscosity grade and the American Gear Manufacturers Association’s AGMA, AGMA EP, AGMA S, AGMA Comp and AGMA EP PAG specifications. 

In practice, larger, heavy-duty gearboxes typically require lubricants that can withstand extreme pressure and temperatures. Synthetic lubricants are formulated to provide superior wear protection, thermal stability and resistance to oxidation and corrosion that benefits severe-service applications. On the other hand, smaller industrial gearboxes in less demanding applications may achieve adequate performance from less-expensive, mineral-based lubricants. There are several considerations that dictate the necessity and frequency of gearbox oil changes. 

WHEN TO CHANGE SMALL GEARBOX OIL

There is a smaller volume of oil in smaller gearboxes, and the oil is typically not filtered while in use. Taking an oil sample from a small gearbox could reduce the oil level enough to require adding fresh oil, which can affect the overall oil condition and make the oil sample irrelevant. For these reasons, the most effective solution is to always change the oil in small gearboxes at the manufacturer-recommended interval.  

WHEN TO CHANGE LARGE GEARBOX OIL 

Large gearboxes can hold 10 or more gallons of oil, so oil sampling does not significantly affect the oil level. These gearboxes may also be equipped with filters, circulating systems and coolers that further extend oil life. Therefore, regular oil analysis is recommended to maximize oil change intervals and reduce maintenance costs. 

GETTING STARTED

With so many different types of gearboxes available and a wide variety of unique operating environments, figuring out which gear oil will provide maximum operational efficiency can be challenging. Choosing the best gear oil is a balancing act of meeting the manufacturer recommendations, environmental requirements and your specific operations and maintenance goals. 

AMSOIL Industrial formulates gear oils to meet or exceed industry–standard requirements for specific applications. For example, AMSOIL Industrial GB Series Synthetic Gear & Bearing Oil delivers superior wear protection, extreme-temperature performance and extended service life in severe-service applications operating in the most adverse conditions. The low-foam formulation of AMSOIL Industrial PT Series Synthetic Power Transmission EP Gear Oil supports 5-micron full-flow filtration and 3-micron off-line or bypass filtration for maximum resistance to scuffing wear and micropitting fatigue on gears and bearings operating under extreme pressures and shock loads. And for superior all-temperature performance, protection and oil life in worm–drive gearboxes, AMSOIL Industrial EP Series Extreme-Pressure Gear Oil meets AGMA 7 Comp, 8 Comp or 8A Comp requirements. 

Find out more by downloading our Extreme Pressure Gear Oils data sheet.

Download our Gearbox Oil Changeover Procedures document to ensure you are maximizing your oil life and uptime.

Consult an AMSOIL Industrial Application Engineer to ensure you are using the correct lubricants and maintenance practices to maximize the performance and extend the service life of your gearboxes.