The power steering "hesitates" momentarily at low RPM in this car. By this, I mean that it seems to stiffen up momentarily while turning the wheel in the driveway or at a stop sign - not at real driving speeds above 20-25 MPH. I took it to a "reputable" repair shop in my home town and their "solution" was to remove the shaft and lubricate it. That didn't work. Precisely accompanying the hesitation, there is a muffled clicking or thumping sound which comes seemingly from under the driver's side dash about every 1 - 3 seconds at low engine RPM. It sounds like some type of pressure switch, but I really don't know. The fluid level is normal, and never requires topping off. Does anyone have an idea what could be causing this? The belts were all recently replaced during the 60,000 mile maintenance, and the car has about 80K miles on it now. 3.2 L engine. Thanks, Carey