Truth closures need one stem and cranks and covers

Thanks for reaching out to us! Regarding the piece you are referring to as the stem, this is the operator worm gear. This helps to turn the gears on the base of the operator, so that the windows cranks in and out. Unfortunately, one this piece becomes dislodged, it cannot be repaired; you will need to replace the entire mechanism.

There is a chance we may be able to supply you with a replacement for the operator you have here. Although, when searching the part number on the arm of the operator, there are a few different styles that populate. That said, to identify the most accurate replacement, I'll need to see a photo of the whole assembly. Especially the arm(s) and how the operator connects to the bottom of the swinging sash.

Please feel free to reach out with any other questions you might have in the meantime.