I had an issue with whining noise that gets louder the higher speed you go, but no drop in performance, went to a local mechanic and he advised that the front differential was faulty and had to be replaced, he showed me how it wasn't transferring any power to the rear wheels on a car lift when engaging the gear in drive and revving the vehicle, so everything went cool and I swapped the front differential with a second-hand one, and had to do some other maintenance jobs such as changing the front propeller shaft, as well as the front propeller shaft bearing assembly, maintenance job cost was about 1,540 USD.
After the maintenance job, everything went back to normal, the loud noise has disappeared, but I'm facing a very weird noise, that only comes on certain conditions, for example, it only make the noise the first few minutes of drive, and only when driving between 50-55 Km/h, and then it disappears, and then it comes again sometimes at 80 Km/h but much quieter, I took the vehicle to the same mechanic twice, and on both times the car stopped making the noise once the mechanic gets in the vehicle and I drive it for a test ride.
It's bugging me out and I'm afraid that the swapped front differential is also faulty. Here's a video if any can help identifying the noise:
Thank you all.