Chrysler Repair: 2003 Sebring Convertible Steering Shutter, power steering pump, tire inflation

Question
When the car is cold and the weather is cool or cold, if you turn the steering wheel it shutters, feels as though there is no power assist and is noisy.  I had it in a shop and they replaced the rack but that hasnt fixed the problem.  The car is a 2003 sebring convertible limited with the 2.7l v6.  Thank you for your assistance.

Answer
The reasons for 'stiff, hard to turn, surge, momentary increase in effort when turning' are: tire inflation improper, low fluid level in power steering pump reservoir, loose power steering pump drive belt, lack of lubrication in lower control arm ball joints, power steering pump pressure low, of a problem with the rack (but that was replaced). If the conditions I listed are not applicable, tell me more about the condition.
Roland