Unknown noise

[Plumpton]

At low speeds with my driver side window down my truck seems to make the sound of dragging a chain or something metallic but only at low speeds. Any idea if this would be wheel bearings or the brakes dragging? I have crawled under and I haven't seen anything hanging down. The truck is a 1998 GMC Sierra.
Any help would be appreciated.

[maxwedge]

Have someone stand outside the truck and listen as you drive by, no way to tell what a noise like that is in this environment.

[2000CAYukon]

If you can tell which wheel the noise is coming from, jack that wheel off the ground and turn it by hand and listen for the noise.

//2000CAYukon

[Plumpton]

Thanks for the info. I appreciate it.