My Gabriel had really loose shoulders (forward and back) and I had to stretch the springs shown in the images to give proper push on the teeth so the shoulders could hold a pose. My Gabriel has solid shoulders now as a result and both are strong enough to hold FT Thomas.

Before opening:




Remove screws 1-5. Notice that you can see the springs from the outside:




This is the housing that holds the teeth and springs:




This shows the cog where the teeth push into. The springs and teeth need to be placed in the grey housing before reassembly:




Be very careful with the springs and teeth when reassembling so they don't go flying somewhere. Hope this helps anyone with loose shoulders.