Hey guys - I have a 99 Silverado, 4x4, 5.3L with the 4l60e. In the past couple of months, I noticed my power steering would tighten up for a fewseconds and then return to easy steering. This always occurs sitting still, like pulling out from a parking position. Well, it finally gave it up. It is not driveable! There is no steering. Its not like the tightness you'd feel if it throws a belt. It is super tight. It takes all the strength I have to turn the wheel a half turn and the tires move about an inch. I was sitting at idle, in drive, and it made a little noise like the idle speed changed for a second. I thought the belt came off. Well, the belt is on with good tension, the power steering reservoir is full. The pulley turns easily and no strange noises. So, what do you guys think? Is it the power steering pump or a steering box?