Grinding noise from front passenger side KUN26R

[Surfermax]

I was wondering if anyone can help as myself and a good mate who is a mechanic cannot locate the issue.

I recently had my front diff removed and schimmed clean as it was leaking oil and all is well on that front.

When I picked up the lux I noticed a grinding and some vibrations coming from the front passenger side that even my wife asked about what was that vibration.

I took the car back to my mechanic and he could not notice anything wrong. He advised it could be the diff "wearing in" as it was cleaned up like new.

It has improved and I noticed that when I rotated some tyres the noise went away or was reduced but when changing the other side it returned again.

I cannot see any issues with the discs / wheels and it does not seem to be a bearing as it is only doing this at low speed and I do not hear it when travelling at 80 km/h and above. Also when I have 4H or 4L engaged the noise disappears.

If anyone can point me in the right direction I would appreciate it.

Thanks.