Count your trundles kids.

What clock gods did I anger ?  I'm a nice person.  I try to do good work and treat people fairly. And this is what I get ?
Junghans B42.  These just seem to be tough clocks to overhaul.  Anyway, this one came in from out of state and I thought I had it finished. Lots of problems with it from previous bad repairs.  As you can see, the "punchers" (remember them ?) already had their way with it. Big difference here is that these punchers took some "pride" in their butcher job and did all the damage on the inside of the plates where it isn't noticeable.

It was running just fine on the test stand for days. just before I was going to put it back in it/s case I thought I would run it thru the chime cycle a few more times.  I noticed that only on the hour it would just hiccup a bit.  Never enough to jam, but just a slight hangup.
Started inspecting with some magnification and spotted the problem. In situations like this you don't even get mad.  It's more of a sick to your stomach feeling.

The little pins on the pinion gear are called trundles.  They're teeth that mesh with the big gear next to them. Unfortunately you need all of them and this gear was missing one !  Bad news is that you can't repair them in the clock so this whole complicated thing had to come completely apart all over again. You gotta be kidding me.

Probably good that I spotted it because after I got it out and started making a replacement, I noticed that several others had been replaced with simple taper pins.  These pieces have to be hardened steel and taper pins are way too soft and were an accident waiting to happen.

This is just one more thing you can't see before you give the repair estimate and you get to eat for an afternoon snack.