I have a 1998 S70 with 105K miles on it. For some reason about 2 month back my car had developed a strange noise that comes behind the steering wheel in the steering column. It is a scweeking noise when I trun the steering. I checked and I have my steering fluid level at right level. Interestingly enough when I added a bit more steering fluid the noise deappeared for a little while. Also when the noise re- appeared again, I just sprayed WD40 (lubricant) between the steering wheel and steering column and it worked for a while too. Any idea what might be the cause of this noise and how to diagnose it?