In many tansmission types, the lubricant fuf1ls other functions apart from lubricating the gearing, for example in
friction elements (synchronizer unit, clutch) in vehicle transmissions, or as a hydraulic fluid (torque converter, retarder,
steering system). The moder trends are now high contact ratio gearing as well as the use of low viscosity lubricants to
reduce chuming losses.
Therefore, at the gear design and lubricant aditive stages, compromises are now necessary which require the most
precise information possible on scuffing resistance of the gearing and lubricant.
It will be demonstrated that the normal test procedures for determining scuffng resistance are not suitable for lubricant
classifcation for vehicle transmissions (GL 4 and GL 5). By reducing the tooth width as well as doubling the speed, the
scuffing test to DIN 51354 standards was increased in severity to such an extent, that the parameters necessary for
transmission dimensioning could be determined for even higher scufing resistant oils.