"Why is the gearbox modified, inspected and repaired by Airbus at 1080 hours?"
Because it was damaged after falling of a truck/lorry during a road accident in Australia...
"The AIBN is aware that the gearbox was involved in a road accident in 2015. The gearbox was inspected, repaired and released for flight by the manufacturer before it was installed in LN-OJF in January 2016."