autozone shows "NYA"..not yet available..they are......(Im on hold with them..yes, they are on speed dial and open 24/7)....they show it, they just dont stock it...

they say it depends upon the type of rear end that is under there....

 

I had a noise like your talking about and it was my u-joint but it was hard to find till it broke and all the needle bearings fell out then I was sure.

 

Check your tire tread, I get this noise a lot and all it is is a stone that is stuck in the tread, that's why I only hear it while moving, wheter or not I'm in gear, and it gets louder the faster I go.