Transmission Rattle

I have a 2001 Dodge Ram 1500 SLT that I bought new. It currently has close to 21k miles and has recently developed an annoying rattle that driving me crazy. It seems to be louder around the 30 to 40 mph range. I have checked for anything that might be loose both in the engine compartment and underside and fender wells. It only happens when driving and seems to come from the engine compartment area. The rattle goes away as soon as I put the tranny in neutral and comes back when I put it back in gear. Could it be something in the tranny? Thanks.

It might be your catalytic converter.....sometimes they develope an internal rattle. when it's in gear and the emergency brake on try using something to protect you from the heat and holding it still. or a mechanics steth-a-scope. sorry for the spelling. good luck
Chris

As I mentioned, the noise would go away as soon as I shifted to neutral, so one day when it was raining I noticed that the noise was gone so I figured it might be in the transmission linkage. I lubricated the linkage and the noise is gone. The noise was being emplified as it traveled up the steering column.