So that diagram DOES SHOW how to properly hookup the deck. I assume that IS in the mower manual, right? Kind of a relief to see that it is documented. Sprytle is right that the BX decks are suspension decks. However, my older B2150 is a ground-rider and is NOT a suspension deck. The B2150 decks have no "stopper bar" on them (and are hitched exactly like the BX decks.) I have two of those B2150 decks. The B3150 is a much newer tractor (over 18 years newer) than my B2150s so I would have to assume Kubota has learned the risk of deck detachment Sprytle described and added the "stopper" bar. Good for Kubota and great for the OP that now he can assemble his machine correctly. Happy ending all around.