I made this last year to replace the original gear that broke on the rail of my freezer drawer since I was unable to find the part online without purchasing the complete rail. My fridge is the KitchenAid/Whirlpool (W10772358) five door refrigerator. I’m bot sure that it was required, but I printed it with Polymaker Polylite PC (transparent ) since I had some on hand. It has been working for ~8 months without issue.
I've included the STL, 3mf, and STEP file in case someone needs to adjust it.
Here's an example of the rail which includes the gear:
Amazon and KitchenAidreparts
The author marked this model as their own original creation.