the truninons on my 55 2nd series just slide in. There is a slot recessed into the trunion. And there is a hole on the bottom side of the tail gate where you can slide a flat head screw driver in to hold the trunion in place while you tighten the bolt. The trucnion will turn freely when you open and close the tail gate. I put a little dab of bearing grease on mine before I installed them.