I have always heard that the T-56 is a very noisey transmission. What kind of noise is normal?

I have a slight whine (i have always had this) and would like to know if this is normal or not. Although, i am not sure if this is in the trans or the rear diff.

 

thats prolly your rear diff., mine does the same thing...it has always done this...so no big worrys...is it mostly when you let of the gas that you hear it?