Breitling Navitimer 806

Servicing an iconic pilot’s watch

Before joining the echelon of luxury Swiss watchmakers, Breitling was one of the earliest purveyors of chronographs for the common man.  In the late 1920’s they sold their patent portfolio to Hann-Landeron and began using movements almost exclusively from the Venus company. Chronographs from Breitling were very much in demand during the 1940’s, 50’s and 60’s. Their most popular models were the Navitimer, Top Time, and Chronomat.

img_1231This Navitimer I purchased off the internet for a fair sum despite its non-working condition. This was a bit of a risk and is generally not advisable (especially since I hadn’t seen the movement and for all I knew it was a rusted mess on the inside) but in the end luck prevailed and I had found a hidden gem.

I was impressed with the overall condition of the watch when it arrived in the post although there was certainly cause for concern. Despite being able to wind the mainspring, the watch failed to run and the chronograph pushers were both jammed in place. Peering through the loupe I noted with growing anxiety that the dial was not properly seated on the movement.

Removal of the caseback brought a bit of relief as I discovered one of the case screws used to secure the movement in place had sheared off and gummed up the works.

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You can see the screw head peeking out from beneath the third wheel here

Careful extraction of the screw head brought the movement back to life.

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This watch is starting to look like a winner!

Pleased with the reading on the timegrapher I proceeded to break down the watch for a full service. First to come off was the rotating bezel and crystal. Beneath the cracked acrylic I found a wonderfully preserved dial.

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Not many watches weather this well

Lesser timepieces have given my heart palpitations when it comes to the removal of the hands and dial- in this case a stiff drink was needed before proceeding.

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I can breath easy now

With the dial off the movement was carefully extracted from the case.

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A soft pillow is used to ward off any scuffs when removing the movement

Placing the movement in a holder for inspection I noted the lack of a beat corrector on the balance cock and the delicate architecture minute jumper. There was some debris, but otherwise the movement was in fine shape.

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A very fine looking chronograph movement

In many ways the Venus 178 movement resembles the Landeron 48 I worked on before; both have the running seconds at 9 o’clock and minute register at 3 o’clock, both are dual pusher chronographs utilizing a lateral clutch, and both have the same design for minute recording and resetting. Where the Venus 178 differs is in the switching mechanism (as it utilizes a column wheel switch) and its ability to record elapsed hours.

Having gained experience disassembling the Landeron earlier, I proceeded using the same methodology here- first removing a spring to release tension, then removing the associated lever. Screws were returned to their respective holes in order to keep them from getting mixed up later. I began with the top side of the movement.

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The chronograph mechanism is slowly broken down
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Theres a bit of dirt in the chronograph works
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Just about down to the base movement

Once the chronograph works had been removed from the top plate, I moved to the dial side to disassemble the hour recording mechanism and keyless works.

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Dial side is tidy but note the road rash on the lower bridge
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A bit more dirt is evident when under the microscope

Considering that there was a screw broken off in the plate, I stopped returning screws to their respective holds as I assumed that I would need to bath the plate in an alum solution (which would dissolve anything fabricated from carbon steel); however, I pleasantly discovered that I was able to extract the broken screw with tweezers once the barrel plate had been removed.

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Screw shaft extracted from main plate

Being able to remove the broken screw with tweezers was a big time saver. Unfortunately I lost a bit of time upon reassembly when I mixed up several of the dial side screws!

Once the movement was completely broken down it was off to the L&R machine for a thorough cleaning.

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It takes many parts to make a chronograph
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Delicate parts like the pallet, escape wheel, and jewels are cleaned separately

With the movement off to be cleaned in the L&R machine, I broke the case down for an ultrasonic bath. The pusher shafts were of differing lengths so I snapped a quick picture for later reference.

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Mental note- the reset pusher is the long one

Following cleaning the entire movement was laid out for inspection. This is an important step to make sure all the parts are together and none require repair or replacement prior to assembly.

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Movement laid out for inspection

Reassembly procedes in the exact opposite direction as disassembly. Typically any service and repair job will require at least two replacement parts- the mainspring and watch crystal. In this case I opted to reuse the original mainspring as it seemed to have quite a bit of life left in it.

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The gear train comes together.
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Bridges and cock reinstalled and ready for timing

My assumption regarding the mainspring turned out to be correct during testing as the base movement had a very strong beat. A 3.1ms beat error needed correction however, and that turned out to be quite a chore. The hairspring has a Breguet overcoil which causes the hairspring to sit quite low on the balance. This resulted in a bit of difficulty when it came to spotting the roller jewel for proper positioning. A bit of trial and error was needed to get the desired result.

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That’s the strongest amplitude I’ve recorded

With the base movement ticking merrily along I proceeded to reassemble the chronograph works without incident.

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The chronograph takes shape slowly
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Assembling the hour recording mechanism

Once the movement was complete the dial was fitted and dusted with a bit of Rodico.

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Recased and ready for the hands

A new crystal was installed in the bezel containing the slide rule.

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The cracked crystal is replaced with a new Sternkreuz medium dome crystal

And the bezel was pressed onto the case using a crystal press.

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Looking a bit better now than before

To complete the effort I replaced the expanding bracelet with a new black leather band.

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Done.

I’ve now completed a Lemania, Landeron, Pierce, and Venus chronograph repair. Next on the agenda is either an Valjoux or Excelsior Park movement. Both are hard to come by and can be budget breakers though. Thankfully I have a drawer full of broken watches in the meantime!

Author: RyMoeller

Amateur watchmaker who also happens to be interested in genealogy, Formula One, and the halcyon days of yore.

2 thoughts on “Breitling Navitimer 806”

  1. Awesome! Great walk-through! I would have lost some weight (sweating) removing those hands! Great work!

    matabog

    p.s. that 343 deg of amplitude is shown because of the 52 deg lift angle set on the timegrapher (instead of 42). Again, Great work! and nerves of steel! That is a 3k$+ watch! Not bad for an “Amateur watchmaker”

    Like

    1. Ah, that’s a good point- I didn’t consider the lift angle!

      Thanks for the kind words. You have no idea how much I learn during each service. I will say there is a discernible difference between a good Swiss watch and a poorly made one though- and those poorly made watches are usually the ones that make me feel all the more amateurish!

      Like

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