I have to post again... not sure why my reply 2 hours ago did not appear.

Anyway, thanks for the reply and suggestions. What I already did so far is that, drive the car again, and accelerate to 75kph, and shift to neutral, the humming sound tend to disappear, but not totally. Mas malakas ang humming niya in acceleration mode than in deccelearation mode (by shifting to neutral). Definitely the humming is not due to engine or the aircon compressor. 'Yong sound nung humming is high pitch ang dating, and once mejo lampas na sa 75kph, nawawala na siya or could be meron pa din pero matining lang kaya di na masyadong madinig.

I will try to bring the car to servitek and have the axle bearing lubricated. Di naman siguro sira ang mga bearings kasi ala naman kabig at di naman nanginginig ang manibela.

Dapat ba sa servitek or mas advisable sa Casa magpagrasa?