Here's a quick tutorial I did a bit ago showing how to take away some of the unnecessary tightness and "catch" areas in Diesels/M3s torso so he'll transform more easily without compromising anything. The ratchets removed aren't necessary for anything and are rather pointless. The edges that are rounded off just need to be softened so all the spinning sections in that area don't catch on each other. Remove two screws and separate the halves. Locate these two ratchet pieces and remove them. One is a little stubborn and may require the aid of a pry tool of some sort. Small flat tip screw driver for instance. Here they are removed. Even without them in place, the areas still have plenty of tension/friction to keep things from being sloppy loose. If you want the sections (torso, crotch flaps, and crotch) to spin more freely around each other without catching, sand these edges down some. I just scraped them away with a straight razor blade.
Sanding the upper-rear edges of the armor-flaps is the #1 thing IMHO. They seemed to catch more than anything else. No matter how loose the waist rotation sections are, if the armor flaps catch at all---they will freeze the waist solid.
I actually don't have that issue...BUT, I did have them catching on the bottom edges hitting the bumper pieces on the thighs, so I trimmed them down some...I neglected to photograph it when I took these so I didn't mention it.
