Wtf???
if none of those work, my bro had that same noise on his 01 supercab. Turns out the E brake was broken, and rattling around in there. Sometimes you wouldnt hear it, other times it would go on forever.
kinda the same thing happened to my truck when ever i would slow down or stop and around corners there was a popping and clunking sound and i replaced my rear u joint and fixed the issue since it was the orignal u joint that i took out there was no grease fitting and the little bearings in side one of the cabs turned to dust

