Today’s differentials are subject to severe operating conditions,
encountering more stress and heat than ever before. Most pickup trucks, SUVs and vans operate in severe
service conditions including towing, hauling, steephill driving and frequent stop-and-go driving environments.
Gear oils are challenged to provide adequate wear protection, while maximizing fuel efficiency.
Approximately 22 components make up the average differential. In order to operate efficiently they require
high-quality, clean gear oil, yet differential maintenance often gets overlooked by motorists. While the first gear
oil change should be performed after the first few-thousandmile break-in, most do not think to change the gear oil
until failure occurs.
AMSOIL gear lubes are multi-functional and formulated for the applications customers use every day.
Follow the vehicle owner’s manual recommendations for initial (break-in) gear oil change. Thereafter, consult
the AMSOIL Product Recommendation and Drain Interval Chart (G1490) for AMSOIL synthetic gear lube service life in
The Dangers of Thermal Runaway
The extreme pressures and temperatures generated by modern
vehicles increase stress on gear lubricants and can lead to a serious condition known as thermal runaway. As
temperatures in the differential climb upward, gear lubricants lose viscosity and load-carrying capacity. When
extreme loads break the lubricant film, metal-to-metal contact occurs, increasing friction and heat. This
increased friction and heat, in turn, results in further viscosity loss, which further increases friction and
heat. As heat continues to spiral upward, viscosity continues to spiral downward. Thermal runaway is a vicious
cycle that leads to irreparable equipment damage from extreme wear, and ultimately catastrophic gear and
AMSOIL Severe Gear® Synthetic Gear Lube demonstrates superior viscosity index (VI) and shear stability
properties, and it is better-equipped to protect equipment against the devastating effects of thermal runaway.