Breitling Navi Heritage (ETA 2892A2) seconds subdial skippiness...

[JeremyLaurenson]

I thought this may be "right" forum to post this.

After 7 months out in Switzerland I got my Navitimer back from Breitling. I had sent it off since its 20 years old to have a complete overhaul done... Nothing major wrong, but I did notice this seconds sundial skipping thingy....

$1300 later and 7 months later, I notice the 'skips' are still here unless the chronometer is engaged.

I would think this is likely the hand binding up and maybe clearance with the dial, but at any rate Im interested as to whether this is something I should be returning the watch to Breitling for and insisting on being fixed.

See below - 1 minute or so of regular running and then 1 minute with the chronograph engaged.

 

Edited May 19, 2024 by JeremyLaurenson
Miss spelling

[eccentric59]

The fact that the seconds runner starts running smoothly when you engage the chrono seconds makes me think the clutch is out of adjustment. That's a guess because I can't seem to find out too much about the chronograph module Breitling used on this model. On other Navitimers they used the Valjoux 7750 which had the running seconds on the left where the hand was mounted on an extended pivot on the fourth wheel. It looks to me that whatever pinion is driving that wheel is skipping teeth.

Given that Breitling (et al) is not forthcoming with manuals or parts, I would send it back and ask for expedited service. They should be sufficiently embarrassed to do that for you at least.

[rjenkinsgb]

Definitely send it back!

I'd guess there is an improperly fitted or adjusted friction spring on the seconds hand drive, a similar principle to those common on centre seconds pinions.

Engaging the mechanism presumably puts more load on the gear train and damps it down.

I had the same jumping seconds hand effect with a sprained centre seconds spring; they damp the hand movement and prevent it jumping or flopping around within the mechanical backlash of the gear train.

 

Edited May 20, 2024 by rjenkinsgb
typo

[Jon]

To be honest, they're not a good movement to have in a chronograph for several reasons. The first is the chronograph mechanism is a 'bolt on' module; If you look at the side of the watch case the crown won't be in line with the pushers, therefore only the branded company would have the ability to swap out the module because they aren't designed to be serviced and definitely not by an independent watchmaker.

Secondly, the ETA 2892 A2 is a great movement, but when the chrono module is used with it it becomes pants, in my opinion/experience.

So, going back to your watch. The problem isn't with the base movement, which is the 2892A2, as there would never be that amount of backlash/flutter in the gear train of that particular movement, it is with the chrono bolt on module that the problem lies and when the chrono sweep second hand is engaged the flutter of the second hand is remedied by the stability of the chronograph mechanism negating that flutter.

Everything in the chronograph mechanism of that movement is powered by a wheel in the centre where the cannon pinion/driving wheel would normally be. I think it is a crappy design deliberately engineered to be disposable due to the time taken to service the module. Give me a 7750 any day!

[JeremyLaurenson]

Shipped back today....