"I just had the transmission rebuilt at a local Aamco (not for this reason)and the alternator replaced and they say it is not transmission related."
Sorry to tell you I had the same issue after Aamco rebuilt my Tranny, told me it was the superchargers waste gate, and wouldn't listen to me when I told it it never made that noise.
I had the transmission rebuilt again, after Aamco's 3rd rebuilt failed and they refused to cover it/rebuild it. Guess what, the noise does not exist anmore, but the mechanic told me it looked like someone dropped a nade int he tranny, Overdrive ring snapped in half. But now I am getting a wierd hesitation, almost like a hiccup while driving. I am thinking it's a fouled fuel injector. I am hoping it's not the transmission again!
Also, for finding noise, a long screw driver works well, where a broom handle does not fit... P.S. do they still make brooms??? Don't u own a swifter??? :P
Good Luck!