@texjohn , John , Below are video links to show how to remove/replace the plastic drive gear. Caution the gear is threaded opposite to normal threads clock wise to remove/counter clockwise to tighten. Good luck.
I hope this helped you out, if so let me know by pressing the helpful button.
https://www.youtube.com/watch?v=Aq6KduZgYx8
https://www.youtube.com/watch?v=0uF2_bALm_o
https://www.youtube.com/watch?v=yX2FpiQuQII