Grinding noise on acceleration
 

I have what seems to be a read diff, Haldex unit problem. Basically there is a grinding noise present on full acceleration, more prominent uphill, it is almost definitely present when AWD activates. The noise is something similar to a wheel spin. Noise is not present when I lightly activate handbrake so AWD disengages by default.

I'll have my care checked up by my local mechanic since haldex units are way over my head. What am I looking at here?

Edit: Forgot to mention. Car is XC70 P2 2007.