Thanks for the prompt reply. It is in low range. I have only ever had it in high range on one occasion, to go a half mile down the road and back to cut a field. I will look for the red button and I have a pdf file that includes the electrical diagrams for the 455D.
After thinking about things, I think it has been going in and out of 4WD since I have owned it (5 years). There have been times that when cutting my back field, I would get stuck in just the slightest wet grass (I have high clay content ground) and other times I would march through 1" of standing water making minor ruts and black marks from "soil squish."
I understand what you said about the rear being fed after going through the front drive wheels, but is the 455D supposed to have all 4 wheels turning or is it like most cars where one or the other front and one or the other rear gets the power depending of loss of traction? Thanks.