Gear balancing time.
Balancing the gears of a clock is crucial. The power needed to drive the gears should be constant. If the gears aren’t balanced then the required power will fluctuate from very little to a damagingly large amount.
When the gears are visually asymmetrical, as mine almost always are, I have to balance them by shaving metal off the back (unseen) side until the weight is balanced. To check this I put the gear on an arbor that’s spinning on precision bearings. When I can stop it in all positions without it turning on it’s own I’m good to go. This involves a lot of back and forth between checking the balance and grinding a little more until it’s just right. If I accidentally remove too much it can be a problem, so it’s best to go slow.