Gear Oils

Axle transmissions place particularly high demands on the oils used, especially with regards to wear protection (AW) and pressure pressure properties (EP). In addition, axle oils must also have very good aging properties. Here, too, longer and longer change intervals up to fill-for-life must be achieved. With stricter emission regulations and directives, axle oils are also increasingly becoming the focus of efficiency optimization in the powertrain.

The coefficient of friction when opening and closing the oil-lubricated multi-disc clutches and brakes in automatic transmissions is important for the functionality of an automatic transmission and the corresponding shifting comfort. This is exactly what automatic transmission oils need to be exactly tuned to. Due to the different requirements of the manufacturers of automatic transmissions regarding the friction coefficient characteristics, no general classification has been established. The OEM specifications are decisive for automatic transmission oils.

Transmission fluids for continuously variable transmissions (CVTFs) are very similar to ATFs. However, in addition to the ATF properties, they are specially adapted to the necessary friction properties for contact between the metallic friction partners (variator to chain/drive link belt). Since powerful hydraulic pumps are usually used in CVT transmissions, corresponding CVTFs must have particularly good foaming properties and good air release capability to prevent cavitation in the pump.

Transmissions in hybrid vehicles are capable of transmitting forces and torques transmitted by both internal combustion engines and electric motors to the drive axle. In addition to the tasks of a conventional dual-clutch transmission oil, the lubricant used in hybridized dual-clutch transmissions performs additional tasks in terms of e-motor compatibility.

Double clutch transmissions generally consist of a dual clutch (either dry or wet) and two "half" manual transmissions. Due to this design, double clutch transmission fluids (DCTFs) combine the properties of an excellent MTF and a high-performance ATF. In addition, the use of hydraulic pumps increases the requirements for foam resistance.

Electrical Driveline Fluids are specially developed for use in axles with integrated electric motors (dry/wet), so-called e-axles. In addition to the characteristics of conventional axle oils, such as a high wear protection and very good ageing properties, the gear oils used here also meet additional requirements in terms of electrical conductivity and copper compatibility.

In modern manual transmissions, the lubricant performs a wide variety of tasks in addition to classic wear protection and also has a significant influence on driving and shifting comfort. In particular, material compatibility with regard to the synchromesh materials used plays a major role in manual transmissions.

Transfer case fluids (TCFs) are used in the transmission types of the same name, for example in all-wheel drive vehicles.
Transfer cases themselves consist of different components (differential, clutch, etc.), so that the oils used have to meet the most diverse and in part individual requirements. The main focus here is on excellent friction behavior as well as wear protection and shear stability.