What is this transmission noise?

What is your question?

I have a 2011 Maxima SV V6 w/ 250K miles. I've dad it from day 1, and the maintenance record is impeccable. I have a noise at the junction of the drive axels at the transmission that sounds kind of like a playing card in the spokes of a bicycle wheel that I only hear when 1st accelerating and then again when slowing to a stop. We put the front end on jack stands this weekend, held one wheel at a time, and then accelerated. We were able to pinpoint the noise at that junction by doing this. Both drive axels have been replaced in the last year. There is no slippage or anything unusual about the transmission function when I'm driving other than the noise. What's the likely culprit and can it be fixed without replacing the transmission?

How long has your 2011 Nissan Maxima had this problem?

A month