Alvin,
Maybe I should not have used the term "short thread" but instead, "long in the shoulder/shank".
My concern is, although the castle nut will tighten down far enough to seat on the face of the steering arm, it is missing a couple threads from the shoulder side. I agree, the need for a washer - flat, locking, or otherwise - seems unusual, and I too would be inclined to opt for a missing thread v.s. adding a washer. Afterall, the ball studs come with castle nuts and cotter pins. If a washer was warrented I would guess they would have been inclded as well.
Just looks unusual to me as the nut threads over the shoulder. More often , the shoulder stops the progress of the nut.
Cavebull
