Jeep Repair: Steering box, automatic transmission fluid, steering box

Question
When I turn my 1990 Cherokee it almost feels like I'm going uphill then it flattens out as I straighten out the wheel again. This happens in both directions on a flat surface with no incline. Is this my steering box or could it be something else. Could this be a DYI'er job?

Answer
It is more than likely your power steering pump.  For starters, make sure the belt is tight and the pump is full of power steering fluid (automatic transmission fluid will do as well) if it is, I would suggest replacing the pump.  Have someone that has done it before help you, there is more to it than taking the old one off and putting the new one on.