Volvo Repair: Moaning like noise on hard left turn, internal faults, traction control system

Question
Greetings once again.  I drive a loaded 1998 Volvo S70 T5(automatic) with the winter package.  I have been experiencing a moaning like noise emminating from my drivers front wheel when cornering hard left.  I work at a Toyota dealership and an experienced mechanic took it for a test drive.  We promptly started doing hard fast left turns in a parking lot with no noise.  So we headed out onto the road, he let me drive this time because he didn't want to push the car at all.  It seems that the moaning only comes when I do a quick start from a stop light making a left turn hard, or when I am speeding up to catch a left arrow(noise only when cornering).  Somehow the mechanic asked if my car had stability or traction control, I said yes; he told me to try turning it off.  The sound could not be repeated after it was off.  I guess I just want to confirm this is the traction control system making this noise, as I am taking this car on a 3000 mile trip within 2 months.  I have never had a problem with right hand turns, but how often do people take a hard right turn in North America, on normal roads; rarely.

Is my logic correct in thinking that the traction control was making this noise, and that my driving habits only make it happen on a left hand turn?

I am also unfamiliar with the 1998 S70 T5's traction control system, what is it designed to do how does it do it and what are its limitations?  

Answer
Jesse, The only moaning that I ever heard on these cars turned out to be the hub assembly, but there is a possibility that the ABS control unit is having some internal faults.  That is a common item to go bad on the 850/70 cars.  The traction control/stability control will kick in if you are hard accellerating into a turn.  Its designed to prevent you from spinning out of control and to keep you on the road.  Roger