I have a 2005 Dodge Magnum RT. I just had the motor replaced and now I can hear noises in my transmission when the car is in Park, Neutral, and Reverse.. When in the drive the transmission makes no noise. I don't know what's going on. I thought it was my lower arm bracket on passenger side.

Park - Tapping sound
Reverse - Low Grinding sound
Neutral - High Grinding sound

 

Maybe take it back to whoever installed the engine and demonstrate it to them?