Are you towing with the truck in your signature F350 ? If you do use a WD you might want to drop the bars while on level ground before backing into that spot. You might also want to wait till after you pull out of that spot and get to a level area before putting the bars on. With that truck and that size trailer you should be able to park it with out any WD bars attached. If you try backing into a spot like shown with the bars on then the chains will mostly go slack and the end of the bars may become jamed into the frame of the trailer.
