Scuffing is usually found near the tip or root of the tooth facing, characterised by material transfer and grooves of varying depth and width in slide direction.
Scuffing will occur in gear teeth when the protective lubricant breaks down the moment a critical contact temperature is reached. A single momentary overload can initiate scuffing (micro welding) and damage the surface with such severity that the protective lubricant film cannot recover and corrective action needs to be taken.
Scuffing can be prevented by providing smooth
surfaces, preventing stress concentrations and the use of EP-additives
in the lubricant.