Modern day vehicles are mounted with a wide variety of different transmissions. They are primarily used for speed and power adaption between the engine and drive axle, for speed compensation between axles and wheels, or for changing direction in the power train. Among other things, a distinction is made between manual transmission, automatic transmission and (hybrid) double clutch transmissions. Furthermore, a distinction is also made between passenger cars and commercial vehicles. When selecting the right transmission oil in the course of a transmission change or transmission repair, the transmission type plays the decisive role.
Requirements for gear oils:
- Lubrication / wear protection
- "Synchro“-compatibility
- High friction stability
- Oxidation stability
- Excellent foaming and air release behavior
- High fuel-efficiency
- Good properties of shifting / low cold viscosity
- Corrosion protection
- High thermal stability
- Long drain intervals or even fill-for-life
- No noise, chatter damping
- High shear stability
- Compatibility with electric components/elements
- Loadcarrying capacity (EP = Extreme Pressure)
- Release contaminant and deposits
These diverse requirements of a modern transmission to the lubricant can only be met if, from an application engineering point of view, the correct lubricant is used in the required quantity in the permissible operating condition in the transmission. It is therefore important to pay close attention to the relevant specifications and OEM approvals for gearbox repairs and gear oil changes.
Manufacturers of electric and hybrid vehicles use the same or related constructions of automatic, dual-clutch or even axle transmissions and therefore gear oils are needed that are often based on already established specifications.
