hey all, just installed my new t series diff (whole new housing)

and now ive taken it for a drive and its only when i back off or take load off the diff it makes a very very loud whine kinda like a circular saw cutting wood

now my old diff made this sound but only when just under load,

i just wanna know why it only does it when i back off and should i get it checked out, i really don't wanna ruin my old/new 4.3

cheers