My 07 Expy is at the dealer being looked at for a rattling sound in the transmission, this only happens when the engine/tranny is cold, after sitting overnight to be exact. when I first start it up and put it into any drive gear D or R about 10-12 seconds after it begins to rattle consistently (think rumble rumble ding, rumble rumble ding) over and over again. When I put it in neutral or park it stops and it wont do it anymore after everything warms up.
Anyone else ever had this problem? Waiting for dealer to call.
Truck has 35,000 miles on it.

 

Dealer called, turns out its an exhaust leak that is only present when cold. the tranny theory was because it only made the noise when in gear.

 

Update, dealer called back and said my cam phaser is making a noise and so they are replacing it as well. Im sure glad I bought the ESP warranty with rental car, cant complain im drivng a 2011 Dodge Ram, which for the record rides very nice but I would never buy one, because its a Dodge.