GE Frame 6B Gearbox Oil Leak

Dear friends,

I am experiencing the Oil leakage issue in Philadelphia gear box of GE Frame 6B gas turbine when it is approaching base load. Below 80% of base load there is no leakage. But as it surpasses the load around 80% of Base load, oil leakage starts at low speed end of load gear box.
We checked the Oil deflector/Demister/Vacuum/Oil Temperature/Vibration everything is normal.

Please suggest your opinion.

looking forward for response.

Thanks in advance.