With improving gear design and manufacturing technology, improvement in metrology is necessary to provide reliable feedback to the designer and manufacturer. A recommended gear roughness measurement method is applied to a micropitting contact fatigue test gear. The development of wear and micropitting is reliably characterised at the sub-micron roughness level. Changes of the localised surface texture features are revealed and are related to key gear meshing positions. The application of the recommended methodology is shown to provide informative feedback, to the gear designer, in reference to the fundamental gear coordinate system which is used in gear performance simulations such as tooth contact analysis.