Sorry, the previous link seemd to not work. Try this one
https://www.stevesnovasite.com/forums/showthread.php?t=322289
. If not, here is what it says, "Wagon Manual Tailgate Window Crank Fix
I corresponded with Novajoe (Thanks for the help!) and he mentioned about making the spring myself. After searching some more, I found a reference to Ace Hardware, so I made the trip.Here are the parts that I bought from ACE hardware to make the spring:
1- #8 compression spring - 2"x7/16" +11/16"x.047. This spring is coned narrow on each end. I cut off about 3 or 4 coils from one end to make the spring. The number of coils that you use will affect the spring tension.
2- 7/16" and 1/2" retainer ring clip to hold the spring on. I forget which one worked best.
3- A washer that fits over the stud. I used this between the spring and the retainer clip because the tip of the spring popped the clip off (which then disappeared!) when I rolled the window back up. The washer puts a barrier between the srping and the retainer clip.
Total cost was less than a dollar and it works great!"
These are pics of the back of the knob. Hope these help.