The December 2018 issue of Windpower Engineering & Development magazine published an article titled How to maintain wind-turbine gearbox & oil health, written by GlobeCore service engineer Frank May.
The article deals with typical wind turbine gearbox issues, with an analysis of the factors detrimental to gearbox operation and reliability. The main idea is that the condition of gearbox oil is essential for normal operation of the gearbox in particular and the entire wind turbine in general. The article also describes the use of the CMM-G unit for gearbox oil change.
You can find the full article here (in the original language).