I had the same howling noise issue in my 2013 Ram 1500 that I took delivery on 3-20-2013. Took it back to dealer to show them that the bolt being removed solved the noise issue. Dealership said I cannot leave the oil cooler lines unsupported.
Dealer brought in a Chrysler Field Service Rep who confirmed an engineering fix from the factory (Not a TSB yet) that involved putting high density foam over the oil cooler lines where the rubber hose portion of the line connects just prior to the fan shroud housing.
Today Chrysler installed the kit, and IT DOESN"T WORK!!!!
What works is removing the bolt and putting foam behind the bracket. Again, Chrysler is concerned that the transmission lines are not being supported, and by removing the bolt, the warranty would be void.
I'm told Chrysler Engineering is still working on a solution. I'm as close to the factory as you can get on this one so I'll keep everyone posted on the progress.
757Guy