https://youtube.com/shorts/TxhJKT3ob...vgROBk6SW9y60h
Does the rapid click sound similar to this video?
This video shows wear on the gears but that's not the actual problem in that case. The motor is not strong enough to extend the eccentric half gear all the way and will fail calibration.
In the video the guy replaced the gear/ shaft he just needed to replace the motor that comes with the pinion gear. (Not that it hurt to get a fresh reviving gear on the shaft)
https://youtube.com/shorts/r7EIcau6-...rGPelbHWibIV43
Here's an example of a working motor going through the full range of motion.