Motor vehicles are equipped with manual, automatic, distribution and axel drives. To ensure proper function of the transmission over the entire period of use, it requires special gear oils for the corresponding modules. Therefore, gear oils are today a structural element in the development.
ATF (automatic transmission fluid) are special lubricants with high requirements for use in automatic transmissions. In particular, good viscosity / temperature behavior, high oxidation and shear stability, excellent foaming properties and air delivery capacity, extreme pressure properties and a defined friction behavior are necessary. In addition to special base oils, ATF oils consist of a variety of additives to fulfil all requirements.
To avoid confusion with engine oils, automatic transmission fluids are colored red.
REQUIREMENTS FOR AUTOMATIC TRANSMISSION FLUIDS:
- Transfer of forces on tooth flanks in the torque converter (CVT variator)
- Lubrication of sliding / rolling elements (rolling and plain bearings, planetary gear sets, freewheels)
- Protection against corrosion, wear, deposits, foams
- Application-specific frictional behaviour of the clutches and brake bands for shifting and transfer capability
- Seal compatibility, so elastomeric not become brittle, shrink or soften
- Optimum viscosity for cold and hot operation
- Cooling of the gearbox from the inside by heat transport to the transmission housing or a separate oil cooler
- High oxidation stability and aging stability for long residence times of oil