2006 Chevy Silverado Power steering noise

I have a similar problem to one I read in your forum. I had some warranty work done which was mainly cosmetic except for the alternator was replaced and also the intermediate steering shaft noise was repaired. I was told that they were not replaced any more, but there was a newer fix for the clunking noise. Some kind of repair kit. After I got it back, it made a fairly load whining noise when turning. I haven't noticed if it is only to the left, or both ways. I will chek that when I get it back from the dealer. This is the third trip and first they changed the fluid, then changed the rack, and now they have changed the pump. They just called and told me that it is now loader than it was and they know nothing else to do. They have now decided that it is "normal" because there are some that are even loader and they have changed all of the parts, plus there are no more fixes suggested by Chevy. I do not beleive this is normal even if all of the trucks do it. It didn't do it until I took it in the first time. I do beleive they are trying to repair it, they just don't know what to do. Being a master ASE tech myself, I know that this sound is usually caused by low fluid or aeration of the fluid, causing cavitation, or possibly a defective releif valve of some sort. All of this having been checked and/or replaced, have you came up with an answer? I know you have heard this before.

Thanks