The retaining threads are stripped.

Thanks for posting. That part is called the worm gear. When it pops out, I am afraid that means the entire operator has broken down and needs to be replaced. Fortunately I believe we can help. This looks similar to either our 39-143, 39-083 or 39-140 Awning Operators. See the diagrams below, compare with your old mechanism, and see if one of these matches what you need.

Dimensions for 39-143

Dimensions for 39-083

Dimensions for 39-140