"Multi-megawatt wind turbine gearboxes operate under demanding environmental conditions including considerable variation in temperature@ wind speed@ and air quality. It is not uncommon for gearboxes rated for a maintenance free 20-year lifespan to fail after only a few years. These gearboxes experience several types of repairable damage including micropitting or ""gray staining""@ abrasive wear@ foreign object debris (FOD) damage@ surface corrosion and fretting corrosion. Wear is greatest on the input stage@ especially on the sun pinion gear. Historically@ grinding is utilized to refurbish these damaged gears. However@ there are numerous drawbacks including but not limited to high capital investment and the extraordinary amount of time and skill involved in the grinding process. Moreover@ nitrided gears cannot be ground and must be scrapped. However@ chemically accelerated vibratory finishing@ or isotropic superfinishing (ISF)@ represents a value adding@ low-cost option for refurbishing both case carburized and nitrided gears. Isotropic superfinishing removes light to moderate gear flank surface damage. The result is a surface with a non-directional pattern with a roughness of approximately 0.08 mm or less. Moreover@ evidence suggests that isotropic superfinishing imparts a finish that increases gear durability and service life in the field. A case study on a sun pinion gear is presented."