streetdoc

I have a 2004 2500 CTD 4x4, around 65 to 70 mph i hear what sounds like a piece of thin metal vibrating against other metal on the front drivers side. It has been doing this for several months, and doesn't appear to be getting worse, other than getting on my nerves. I can't find anything loose, or out of place. Also on dirt roads i can hear a noise that a ford makes when the pitman arm bushing is out.

Thanks for any info.