For the past few weeks every time I initially turn the steering wheel after the car has sat for a few hours I feel a roughness like the steering shaft is dragging in a dry bushing. This only happens when you first turn the wheel to take off & everything feels normal after that. Is this a sign that the power steering unit may be on its way out or is there some bushing that the steering shaft runs through that may need lubing up under the dash or in the firewall?