Volvo Repair: V70 XC Rear Wheel Noise, rear wheels, awd

Question
I am looking at purchasing a 98 V70 XC, when test drove the rear wheels made a constant "grinding" noise. The owner showed she had it checked and the has receipts it was undetermined what the actual cause was,  but could be the rear differential bearings....could you advise if there is any history on similar issues or if you have an opinion as to what it might be? Thanks

Answer
Rich, save yourself a headache and just walk away from that deal.  If you are going to get a V70, get the normal one without AWD.  You will thank me later.  My opinion on the noise is it can be a number of things and without looking at it and hearing the noise, I would only be guessing.  Roger