Argh. Breaking pallet pivots

[WpgRob]

Beginner here. Of about 60 watches I’ve serviced and repaired, I’ve broken a pallet pivot on three, always during disassembly, and usually when the old oil has transformed to glue. Each watch was Swiss, in case that makes a difference. Here’s what happened in each case:
- unscrewed the pallet bridge or cock

- gently inserted a screwdriver in the  slot under the pallet bridge or cock

- gently but firmly rotated the screwdriver, avoiding a forwards force on the screwdriver. If alignment pins stick, the cam action is alternated back and forth between back corners of the plate.

- heard a small but horrible click.

Is there a special tool or technique for safely lifting the pallet bridge? Should everything be soaked in naphtha before beginning disassembly if there’s any sign of old oil gluing parts together?

Thanks!

Rob

[HectorLooi]

55 minutes ago, WpgRob said:

Of about 60 watches I’ve serviced and repaired,

60! Wow, that's a lot.

Can't say I understand the problem because disassembly is usually quite uneventful, except for springs launching into space. Most people break pivots during assembly.

I use a homemade brass pry tool to loosen parts. It's just a short length of hard brass wire sharpened to a chisel point. Don't pry at just one point and crowbar it out. Pry at the notch and when a crack opens up, slip the pry tool in and loosen it at a few more points until the bridge is free.

[Nucejoe]

 If a runner, I usually let the movement run in naphta for a minute, some movements need a bit of encouragement to run in liquids, so a quick dip of the movement in naphta then remove and encourage the oscilator with puffer, repeat several soaks. 

Or if you don't want to soak or dip the movement in cleaning solution ,   keep putting naphta on jewel holes as the movement runs on bench.

A pre-clean of some sort  helps.

 Avoid lifting out the fork with tweezers or any tool.

 Try blowing fork pivot out  with strong puff of air from jewels holes back side.

Good luck .

 

 

 

Edited April 29 by Nucejoe

[caseback]

Wiggle it back and forth, small steps, keeping the pallet cock as level as possible and take your time (!). You could also use an extra tool as a safeguard at the jewelled end to avoid pressure on the pallet fork.

You also mention lubrication... On the pallet fork pivots??

[JohnR725]

it would be nice to have the exact model of the watch the or a picture so we can see exactly what you're talking about. this is because the definition of Swiss watch could be a variety of things and it be helpful if we could see exactly the watch your dealing with

then in professional watch repair at least some professionals they do pre-cleaned watches. In other words the hands and dial come off and the entire movement assembled goes through a cleaning machine sometimes I think a shorter bath perhaps so everything is nice and clean for disassembly makes it easier to look for problems.

Then other professionals don't like pre-cleaning because it basically obliterates the scene of the crime. Especially when dealing with vintage watches where you're looking for metal filings and problems that may visually go away with cleaning.

Then usually super sticky lubrication isn't really a problem for disassembly and typically shouldn't be a problem on a pallet fork bridge because there shouldn't be any lubrication on the bridge at all as you typically do not oil the pallet fork pivots.

 

[Poljot]

16 hours ago, WpgRob said:

Beginner here. Of about 60 watches I’ve serviced and repaired, I’ve broken a pallet pivot on three, always during disassembly, and usually when the old oil has transformed to glue. Each watch was Swiss, in case that makes a difference. Here’s what happened in each case:
- unscrewed the pallet bridge or cock

- gently inserted a screwdriver in the  slot under the pallet bridge or cock

- gently but firmly rotated the screwdriver, avoiding a forwards force on the screwdriver. If alignment pins stick, the cam action is alternated back and forth between back corners of the plate.

- heard a small but horrible click.

Is there a special tool or technique for safely lifting the pallet bridge? Should everything be soaked in naphtha before beginning disassembly if there’s any sign of old oil gluing parts together?

Thanks!

Rob

Hope you let the mainspring completely unwind before removing the bridge? Use not only a screwdriver, but a pair of good tweezers with curved ends. This will allow to move various sides of the bridge straight up while keeping it in parallel with the main plate. If you use a screwdriver only and top pivot is stuck, then a bridge is being lifted under angle and then you hear that "horrible click". Usually it takes only one instance to learn such lesson in life

[WpgRob]

Thanks to all for the helpful hints. From now on, I’ll give every movement a soak in naphtha, then use curved tweezers to lift straight up.

 

I didn’t get photos of the currently broken pallet pivot, but photos of some previous pallet pivot disasters are attached. The AS1382 automatic movement has a dial branded “Boillat Les Bois,” and has a power indicator. (That made the bungle painful). The other is a Bulova 11ACC. Interestingly, the shape of the pallet cock is about the same for each.

 

 

18 hours ago, caseback said:

Wiggle it back and forth, small steps, keeping the pallet cock as level as possible and take your time (!). You could also use an extra tool as a safeguard at the jewelled end to avoid pressure on the pallet fork.

You also mention lubrication... On the pallet fork pivots??

Good catch - maybe this is another reason not to lubricate the pallet pivots. Thanks for the input.

[Poljot]

It appears that you use a screwdriver like a beer bottle opener. You wedge the screwdriver blade under the side of the pallet cock and lift the screwdriver handle creating an angle. Voila - your lower pallet pivot either gets bent or broken. Work from two sides  and confirm that upper pivot is leaving the hole jewel when you just beginning to lift the pallet cock.

What kind of magnification & light do you use? It's very helpful to use a good microscope with light source.

[WpgRob]

5 hours ago, Poljot said:

Hope you let the mainspring completely unwind before removing the bridge? Use not only a screwdriver, but a pair of good tweezers with curved ends. This will allow to move various sides of the bridge straight up while keeping it in parallel with the main plate. If you use a screwdriver only and top pivot is stuck, then a bridge is being lifted under angle and then you hear that "horrible click". Usually it takes only one instance to learn such lesson in life

Yep, slow learner! All 3 of these watches had old dried up oil that interfered with removing pivots. But you have a point: Pivots like the train wheels have are usually under a larger plate so that lifting one end induces a smaller angle than the same deflection would on a pallet bridge.

2 minutes ago, Poljot said:

It appears that you use a screwdriver like a beer bottle opener. You wedge the screwdriver blade under the side of the pallet cock and lift the screwdriver handle creating an angle. Voila - your lower pallet pivot either gets bent or broken. Work from two sides  and confirm that upper pivot is leaving the hole jewel when you just beginning to lift the pallet cock.

What kind of magnification & light do you use? It's very helpful to use a good microscope with light source.

Confirming the pivot has left the hole is a good idea, and honestly I hadn’t thought of it. When disassembling, I don’t use magnification much, but now it’s clear that decision was a contributing cause. For lighting and magnification, I use a bright fluorescent adjustable lamp on an arm, a 10x loupe and a cheap digital microscope.

[Poljot]

Pallet fork pivots should have a minimum amount of oil if any, depending on caliber size. Therefore, if you see any amount of whatever oil someone applied on those pivots - be careful. You can always check if pallet fork is moving freely before lifting the pallet cock. I've seen same scenarios with old 18s pocket watches. Some dried red gummy stuff. I had to lightly push down top pivot while gently lifting the pallet cock. Use sharpen peg wood  - same type that is used to clean hole jewels.

[Nucejoe]

 To lift the fork when bottom pivot is in jewel , rodico,

I have broken one pivot myself and I know how easy it can happen. 

 As JohnR says , there shouldn't be any oil on fork pivot/jewel , yet there is often the problem of previous watch destroyers who might have lubricated them.

I usually flip the movement ( mainplate up ) and tap on mainplate which often causes the fork to fall out .

 Let keep it a secret just between the two of us, I have broken escape pivot too. 

Regs

[Neverenoughwatches]

5 hours ago, Nucejoe said:

 To lift the fork when bottom pivot is in jewel , rodico,

I have broken one pivot myself and I know how easy it can happen. 

 As JohnR says , there shouldn't be any oil on fork pivot/jewel , yet there is often the problem of previous watch destroyers who might have lubricated them.

I usually flip the movement ( mainplate up ) and tap on mainplate which often causes the fork to fall out .

 Let keep it a secret just between the two of us, I have broken escape pivot too. 

Regs

If using the slot in the cock or bridge, it should really only be used for the very beginning of the removal process. Resist temptation to lever it more than necessary. The distance between it and the pivot is usually short, so the angle  between the hole jewel and pivot increases quickl. This can reduce the sideshake in the jewel hole to zero , either snapping the pivot, bending it or damaging the jewel. Once a gap has been started  using the slot for leverage, begin lifting points further away from the jewel until the cock can be taken up cleanly. 

[mikepilk]

 

On 4/29/2025 at 4:13 AM, HectorLooi said:

I use a homemade brass pry tool to loosen parts. It's just a short length of hard brass wire sharpened to a chisel point. Don't pry at just one point and crowbar it out.

I made exactly the same tool. Useful to prying apart brides and balance cocks, and pushing on parts during assembly without damage.

8 hours ago, WpgRob said:

I don’t use magnification much,

I think that could be your problem. Without magnification you might not be aware if the pallet is being slightly twisted.

It's odd, that of all the pivots I have broken, I don't think I've ever broken a pallet pivot.  BUT I do all work under a stereo microscope.