Chrysler Pacifica Forum : “Popping/Knocking when downshift at 30 MPH”

Popping/Knocking when downshift at 30 MPH

My 04 Pacifica AWD pops/knocks as the car is downshifting to go below 30MPH.  The mechanics say the can hear the noise, but it isn't loud enough for them to figure out what it is.  If anyone has any suggestions, I would greatly appreciate them.