2014 2500 Ram with Cummins. The auto trans was just replaced with a new trans, when shifting from reverse to drive there is a loud buzzing noise coming from the transmission, for about 1 second. While looking at the rear driveshaft when it's making this noise I noticed that it's vibrating, trying to turn. The front driveshaft out of the transfer case doesn't do this, just the rear. The noise is coming from the trans area, could this be a trans or transfer case problem? The truck has 98,000 miles on it (trans is new).