I have a 2011 SXT with 6000 kms up so far. I too am experiencing a transmission thud on occasions when going from Park into reverse and from reverse into drive, mostly when the vehicle is first started. Now more conscious to move the shifter much more slowly and to pause in neutral when going through the gears. This was the same issue raised by the motor correspondent in the Globe and Mail (Canada's major newspaper) with their recent review of the Chrysler 200. Never experience this problem with our Honda CRV nor my Chevy Mailbu so believe this is more a Chrysler problem. Overall the Journey has some very positive attributes, - comfortable, bags of room and storage and well thought out features and value for money BUT I am starting to have concerns that the transmission is going to be the weak link.
If anyone finds a dealer who has a solution for the thud. please pass it on.