Hi, I have the exact same issue.
I have had my mechanic check the car twice and both times he couldn’t find anything wrong. I am stating to think it may also be fluid level in the front axel. I recently had my front axel shimmed (hence the visit to the mechanic) as the front axel was leaking after a recent 4x4 trip to Fraser Island and ever since then this noise is occurring and has everyone stumped. BTW the noise does not appear to be evident when the car is in 4H, only 2H. I also think it may be the tyres as I recently also had a balance and alignment done and car drives perfectly straight and there is no shaking on the wheel, only vibrations when above 90kmh.
