Looking for replacement crank for Caradco (left side) will buy both.

Thanks for posting. When the spline pops out like that, I am afraid that means the entire operator has broken down and needs to be replaced. Fortunately I believe we can help. See if our 39-155 matches what you have. Review the diagram below and let me know if any dimensions differ in any way. For a compatible cover and handle with this operator, see the 39-107 and 39-114L, sold separately.

Dimensions for 39-155

Excellent. Let me know if you need anything else, and many thanks for reaching out.