1996 Chevy S-10 front differential problem

We removed the front differential and found that the left side output shaft is hitting the pin that holds the gears in place is this normal and if so why is it making so much noise all of a sudden noise just recently started and is reason for removing diff. We have replaced both front c/v shafts already and all the bearings inside of the diff still look good - just not sure what to do about this condition is there supposed to be a spacer or something to keep this shaft from hitting the pin inside or is there other problems?