Title: ETA 2836-2 Not Ticking After Pallet Fork Replacement – Need Assistance

[TimepieceTinkerer]

Hi all,

I’m currently working on an ETA 2836-2 movement. I replaced the pallet fork with a new one (ETA2801710, sourced from CousinsUK). After full reassembly and lubrication, I’ve encountered a strange issue:

The movement is fully wound and has power.

When I fit the balance assembly, the movement does not tick at all—completely dead.

When I remove the balance, the gear train suddenly releases and spins freely, indicating power was present.

The pallet fork just “floats” without snapping side to side—almost as if it isn’t even there. No interaction with the escape wheel is visible at that point.

However:

Before fitting the balance, I checked the pallet fork manually — it was working as it should, clearly interacting with the escape wheel.

I’ve inspected the pallet bridge jewel (where the pallet fork sits) and everything looks normal. No signs of misalignment or obstruction.

I’ve rechecked everything I can think of and I’m completely out of ideas. Has anyone seen this behaviour before? Any suggestions would be greatly appreciated.

Thanks in advance!

TT

[AndyGSi]

Is the pallet fork aligned with the roller on the balance.

Can you post photos how the pallet fork sits in relation to the escape wheel.

[Neverenoughwatches]

Why did you change the pallet fork ?

[LittleWatchShop]

Did you install the fork upside down? 

[RichardHarris123]

5 minutes ago, LittleWatchShop said:

Did you install the fork upside down? 

Good question but why does the power release without the balance? 

[Nucejoe]

‌Are you sure the fork still has 2 pivots? 

Pallets haven't moved?   Or as  said  installed upside down? 

 

[TimepieceTinkerer]

Hi all,

Update:
Thanks to everyone who responded — I really appreciate the help!

It turns out the issue was caused by a loose cannon pinion on the main plate, which prevented the train wheels from sitting correctly. That’s why the movement wouldn’t tick with the balance in place, and the pallet fork appeared to "float" without engaging. Once that was fixed, everything snapped into place and started working as it should.

I had replaced the pallet fork because I accidentally broke the pivot on the original one. @Neverenoughwatches

P.S. I definitely need to upgrade my photo setup for situations like this — it's really difficult to capture clear views of small parts with a normal phone camera.

[HectorLooi]

Pretty decent close-up photos can be acheived with a clip-on macro lens attached to a handphone.

15x Micro Lens Pink Phone Camera Lens Clip Light for Manicure Beauty Eyelash Nails Macro Photography Lighting Tool Adjustable
https://a.aliexpress.com/_mP5iKcR

 

[Neverenoughwatches]

how might a loose cannon pinion  explain why the movement wouldn't tick with the balance in place or the lack of fork/escape wheel interaction ?

[AndyGSi]

I'd thought the same along with the fact that they'd already stated the train ran without the balance?

[TimepieceTinkerer]

Initially, when I fitted the train bridge, I noticed that if I tightened the screws all the way down, the wheels wouldn’t function. But if I left the screws slightly loose, everything worked fine. That made me suspect something was misaligned. After checking further, I found the cannon pinion was loose and causing the fourth wheel not to sit properly.

Because of that, the train wasn't fully free under normal assembly, and once the balance was in place, the pallet fork and escape wheel couldn’t interact properly — they were effectively blocked.

I’m not sure why the cannon pinion was loose, but I used my staking tools and applied a bit of pressure to tighten it. I'm an amateur, and this is my very first ETA movement.

If anyone has any idea why the cannon pinion might have been loose in the first place, or if it’s likely to come loose again, please advise — I’d really appreciate the insight.

[Neverenoughwatches]

I'm  still not sure why the cannon pinion would cause this issue. With no cannon pinion at all the train can run and the movement tick. Anyway you have it fixed, so that's good.

[TimepieceTinkerer]

You're absolutely right — normally, a missing or even removed cannon pinion wouldn't stop the train from running or the movement from ticking.

Just to clarify: the part I’m referring to isn’t the removable cannon pinion on the center wheel — it’s the fixed pinion that’s pressed into the mainplate underneath, which drives the motion works. I may have misused the term earlier. That pinion was loose in my case, and it caused the fourth wheel to sit out of alignment, which jammed the train when the bridge was fully tightened. Once I tightened that fixed pinion with the staking set, everything seated correctly and the issue was resolved.

Appreciate your input — and thanks for helping me describe it more accurately.

[AndyGSi]

20 minutes ago, Neverenoughwatches said:

I'm  still not sure why the cannon pinion would cause this issue. With no cannon pinion at all the train can run and the movement tick. Anyway you have it fixed, so that's good.

That's because it's not a cannon pinion and just a centre tube.

If this was the fault I still wouldn't have expected it to run without the balance.

Edit

@TimepieceTinkerer To clarify.

Did you test the train ran smoothly with everything tightened down before fitted the fork and balance?

 

Edited 2 hours ago by AndyGSi

[TimepieceTinkerer]

Thanks for shedding light on the exact problem — you're right, it's the centre tube, not the cannon pinion.

That was the issue, and after tightening the centre tube, everything now sits correctly. The train bridge can be fully tightened and all the wheels run freely.

I haven’t tested the pallet fork yet as I haven’t refitted it, but I’ll be doing that shortly to confirm if the issue is entirely resolved.
@Neverenoughwatches Sorry for misusing the term earlier.

[AndyGSi]

This would have been seen before the fork and balance were even fitted
if you carried out a test on the train wheel as a matter of course.