2006mdx

My 2006 MDX touring has almost 103,000 miles. It recently stated to make a whirring (or humming) noise when I turn the wheels all the way left or right and accelerate like when I make a U turn. It does not make the noise when I make a normal left or right turn. It does it in drive and reverse when accelerating. My mechanic was originally guessing that it is the differential making the noise and emptied all the rear diff and transmission fluid and refilled. He said he changed the trany fluid twice because it didn't look clean after the first dump. I do drive it aggressively at times. I have read that swapping out the fluid can fix that noise but it didn't fix it for me. I have also read on another MDX thread that if I replace the O ring in my power steering it might fix the problem. I might do that first as it is a cheaper fix. I don't mind the noise when I U turn. I just don't want the differential or trany to blow up if there is something I can do to inexpensively diagnose and fix it now. Anyone have this problem/solution before? My mechanic says that if the differential stops working that I can still drive the car, it will just be 2 wheel drive instead of all wheel drive. Does that sound right to you? I would like to know how you would know if it only goes 2 wheel in case I am heading to the mountains/snow that particular weekend. Would be a bad way to find out when you are stuck in a snow bank and can't get out!

2006mdx

Forgot to mention that it drives great. the gears shift smoothly when going 0 to 80, in a hurry or when slowly entering a freeway on ramp or off ramp. The noise is definitely not a popping sound. I had to replace CV boots on my Odyssey when it started to pop on left hand turns. If it was a transmission problem it would make the noise all of the time, not just during U turns.