Window crank

Thanks for posting. When that worm gear pops out, I am afraid it means the entire window operator has broken down and should be replaced. We likely can help, but we'll need to see photos of the entire mechanism including the link arm(s) that push and pull the window. A bird's eye view of everything would be best. We'll do our best to help you from there. 

No worries, that's perfect! This looks like it might be the 39-032 EntryGard Dual Arm Operator (the opposite-handed version is the 39-031). Just make sure the dimensions for the arms as listed below matches what you have. Let me know if anything differs, in any way. For a new cover and a new handle, see the 39-107 and 39-114L sold separately.

Dimensions for 39-032