Need replacement

Thanks for posting. Yes, when that worm gear pops out, I am afraid that means the entire window operator has broken down and should be replaced. We can help with that, but we'll need to see the entire mechanism, including the arm(s) that move the window. A bird's eye view, with the window open or the operator removed from the window, would be best. We'll do our best to help from there. 

Thanks for getting back to me, that's perfect. I think this probably the 39-031 Dual-Arm Operator. Just make sure the dimensions match what we show below. let me know if anything differs. For a new cover and handle, see the 39-114L and 39-107 sold separately.

Dimensions for 39-031