Kevin,
I purchased a 318 3 weeks ago with a 46" deck, while looking the machine over I noticed the adjustment bolt for the deck was bent. I have a newer 48" deck from my 317 which I want to put on. Being as the lift arms were different I went to my dealer and purchased the new lift arm and a new adjustment bolt. I have a couple different owners manuals for the 46" deck and each manual stated to put the adjustment assembly on different sides. The way the tractor was when I received it, the adjustment was on the left side (determined by sitting in the seat). When I looked at that setup it was evident that would not work, too much of an angle. I swapped the lift arms, putting the adjustment on the right side and so far so good.
Bob