mechanical trouble shooting please help

2011 taco V6 4.0 4X4 (AUTO)

I've been dealing with an annoying front end noise coming from the wheels that i cannot trouble shoot. ill do my best to describe the noise in the following sentences...only makes the noise while driving, a rattling sound, metal on metal, VERY similar to a rattle snakes rattler (no theres not a snake in me truck, mayte!). its been going on for over a month now and at first it only made the noise when hitting the breaks. now its doing it constantly without hitting the breaks. Ive pulled all 4 tires, blew out debris with air compressor, rear drum brake shoes are good and front brake pads are like new... wheel bearings are good. ive been reading on these forums and was given an idea that it could be the dust shield rubbing behind the rotors? and to bend them back a little. so i did that...still making a noise...please any mechanically inclined taco lovers out there, please give me some advice...thanks for reading.