Vent window crank

My 67 Fury has the hand crank front vent windows. When I crank them it doesn't feel like it's engaging but I can move the vent window open or closed depending on the position of the crank by hand. The crank will still lock them closed as long as I move the window by hand. Before I remove the door panel and hardware, is this an easy fix or will I need to find parts?
Author: Timmayy