Gear Oils & Final Drive Oils

Gear oils are made specifically for differentials, transmissions and transfer cases in vehicles and other machinery. The higher viscosities better protect the gears ensuring transfer of lubricant throughout the gear train. Some modern automatic transaxles (integrated transmission and differential) do not use a heavy oil but lubricate with the lower viscosity hydraulic fluid, which is available at pressure within the automatic transmission.

Most lubricants for manual gearboxes and differentials are hypoid gear oils. These contain extreme pressure/antiwear additives to cope with the sliding action of hypoid bevel gears.