Belt twisted twice

This belt is (was =) relatively new, so I think I’ll:

  1. replace #338 and leave the current belt - to see if it will continue to twist. After it snaps/twists/exhibits some other abnormal behavior, I’ll:
  2. replace the belt and see if it twists (with new part #338, but old freewheel).

That sequence should give more data about the problem.

What is the recommended torque for bolt #379? I was unable to find it in the manual.

You are right - it might have happened during rear wheel removal and installation in the field, when torque wrench is unavailable.