Trauma1 said:
It sounds like it is the interior door panel. It is a little loose and shakes on rough roads. The door itself is solid. Thanks for the reply.
Yeah, this forums needs all the replies it can get, so I'm doing everything I can to respond to the most current posts, if there is anything that I can contribute.
Have you (or the previous owners, if you bought the truck used) installed any aftermarket stereo equipment or replaced a window motor/lock actuator? Anything that would require that the interior door panel be removed and reinstalled? If so, you could have a bad attachment clip or two in the panel, they get messed up easily if someone yanks the door panel off without using a little care. One of the old clips might even be sitting down in the bottom rattling around. It's hard to tell without actually hearing what the rattling sounds like.
Thats really the only thing I can think of that would cause the sound you're describing, but I'm far from any kind of expert. It's something to take a look at, at least.