Question on hour hand creeping in the opposite direction

I bought a 145.022-69 which was ast serviced in 2009. The watch is running fine at -5s, chronograph also runs. But when I start and stop the chronograph for the first time since received it, the chrono hour hand resets at about -1mm before the 12 hour mark. I notice that as I use the chronograph more and more, the hour hand resets further away before the 12 hour mark. Right now it resets at about -0.5mm after the 11 hour mark. There was only once when the hand reset perfectly at 12, but that was unintended because the chrono somehow reset when I pressed the stop button, i.e. pressing stop button while it was running sometimes stop and reset the chrono simultaneously. What could possibly cause this anomaly and would it require major part replacement? Thank you for reading and I appreciate your help.

Hello sounds quite odd but I have encountered this before when servicing chronograph watches. It sounds like the pipe of the chronograph hand is loose on the pinion. The reset force is quite strong when resetting and the momentum of the hand causes it to travel further back than required.
Sometimes the pipe could be split or loose, sometimes possible repairs include solder or riveting but not always successful. The most successful repair would be a new hand. But on a vintage model like this you would have to be careful to source the correct one.

Most likely the hour recorder hand is either loose on the post, or the rivet between the tube and flat portion of the hands is loose. Both can be corrected in most cases, and in some instances where it is worthwhile, a new tube can be fitted, but quite honestly this would not be worth it for this one as new hands are readily available.

For the chronograph resetting when the stop button is pressed, this is most commonly from a part called the "stem bolt for hammer" being broken or missing. However it being intermittent as it seems you are saying means it could be something else. Both issues can be rectified at service, which at 6 years since the last one it's pretty much due.

Cheers, Al

There is a thread here where Al talks about the stop/reset issue. Do a search and you should find it...

An interesting observation on the hour recorder hand issue :

Yesterday I let the chronograph ran for 6 to 7 hours. I let it run while winding the watch before I went to bed. I noticed the hour recorder hand advanced about 2 hours while I wound it. Could this be a symptom of a broken mainspring? The power reserve is about 44 hours after full wind.

This is not normal, but it's not an indication of a broken mainspring. If you wound the watch and you felt it come to it's normal stop at full wind, the spring is not broken. If the crown winds and winds and never comes to a stop, that is an indication that the spring is broken.

The hour recorder is driven off the mainspring barrel. If the hour recorder advanced while you were winding the watch, the hour recorder stop lever likely needs to be adjusted so it brakes the hour recorder runner more effectively. I would also likely look at the friction spring set-up for the driving pinion for the hour recorder on the barrel, just to make sure it's working as it should.

6 years since last service means you should be getting it looked at, in particular with these problems cropping up.

Cheers, Al