its that noise that you hear when an airplanes turbines are spinning. as you drive faster, the noise gets louder and more noticeable.

my old diff made this same noise before it blew. well...it made that noise. then you just heard clicking noises..and then it blew.

so for my new diff, right before the whining noise came upon, my car (when moving slowly or from a start, you would hear a short of clicking noise as well but it was light. it was like click click click and then it goes away. could it be the gears on the inside?