I'm chasing something similar down as well. The sound I get is a groaning and squeak when I first back out of the garage. At first I thought it was only when moving and turning in reverse but after spending more time on it, I get it while sitting still or moving forward also, it is just much quieter. Once the car is warm I barely notice it (likely because I'm not in reverse that much) My car has new front lower control arms, tie rod ends, and I read the rear diff could also cause similar noise, so I changed the fluid and friction modifier. None of that helped. Yesterday I changed the serpentine belt (just because it was old, it didn't look bad) and the noise seemed to disappear. I'm not saying this is the solution, because I still have some clunks and squeaks to deal with, but the loud reverse whine when turning seemed to be gone. That said, I've only driven it once since the belt swap. Just something to consider before replacing pumps and steering racks. I was sure it was a rack or pump problem, but I'm not so sure now. Regardless, I'll keep an eye on the car is and this thread and hopefully we figure it out.
