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Stuck ratchet wheel screw

PostwarO27
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PostwarO27 Watch Enthusiast

PostwarO27

Posted
Posted

I'm working on an old AS984 movement from the 1940's and cannot get the ratchet wheel screw loose.  I've soaked it in numerous solutions  and even tried taping it on my staking set to loosen the crud that is binding the screw to no avail.  I'm starting to strip the screw head and don't want to continue  without reaching out to the forum.

What are my other options?

George

Neverenoughwatches Distinguished Member

Neverenoughwatches

Posted
Posted
2 hours ago, PostwarO27 said:

I'm working on an old AS984 movement from the 1940's and cannot get the ratchet wheel screw loose.  I've soaked it in numerous solutions  and even tried taping it on my staking set to loosen the crud that is binding the screw to no avail.  I'm starting to strip the screw head and don't want to continue  without reaching out to the forum.

What are my other options?

George

Same issue here a couple of days ago George. As ww  and nickelsilver says, test for the common scenario of a reverse threaded screw. Feel for some movement each way. After a few experiences with them it will become second nature to test and feel for tightening and loosening of a rachet screw regardless of its threaded portion direction of up or down the screw.

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PostwarO27 Watch Enthusiast

PostwarO27

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Yes, checking for LH threads was the first thing I did.  I've yet to come across a movement with LH threads in both the ratchet and crown wheels but I've only been at this a couple years so I;m sure I'll run into one eventually.

I haven't tried the heat but as soon as I'm done typing here, I will be.  I disassembled the movement as far as I could and right now I have the barrel bridged sandwiched  in between the ratchet wheel and barrel arbor and that subassembly is soaking in a ramekin of WD, which as a toolmaker by trade, was our go to solution for loosening corroded nuts and bolts.  The click is still in place to help keep the barrel from spinning when trying to loosen the screw.

 

 

Darthkram Member

Darthkram

Posted
Posted

AS 984 is definitely a Left Handed ratchet wheel screw.

I made that mistake on the first one I disassembled and wound up with a snapped screw head as a prize!

I just tested a couple other AS 984 movements I have and they were also both LH ratchet screw.

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PostwarO27 Watch Enthusiast

PostwarO27

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8 minutes ago, Darthkram said:

AS 984 is definitely a Left Handed ratchet wheel screw.

I made that mistake on the first one I disassembled and wound up with a snapped screw head as a prize!

I just tested a couple other AS 984 movements I have and they were also both LH ratchet screw.

I was starting to think the same thing.  I noticed that the click rotates in a different direction than all the other movmenets I've worked on.  The head of the screw is the same as a RH screw, there is no marking of sorts to alert the mechanic as to the direction of thread.

 

However I still can't budge the thing.  Its like the screw and barrel arbor are one piece.

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PostwarO27 Watch Enthusiast

PostwarO27

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SUCCESS!!

I managed to separate the ratchet screw from the barrel arbor.  I ended up soaking the subassembly in CocaCola overnight and with a couple of taps on my staking set with a punch collinear with the screw axis, it loosened up the crude holding it together.  LH thread.

I'm going to mark that screw head with three lines to indicate to whoever takes it apart in the future that its a lefty.

 

Thanks for the tips y'all !!

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  • 1 year later...
signcarver WRT Addict

signcarver

Posted
Posted

I'm having the same issue with an AS 1002 movement. However I think the 1002 ratchet screw is RH thread. My conclusion is based on the fact that the click is "standard" not reversed as mentioned above. Also, i can look inside the barrel arbor where the original screw broke off and see right handed threads.

Still i can't get the screw loose on my donor watch. Currently i applied Liquid Wrench, which is similar to Kano Kroil. 

If i want to try heat, can i heat up a "junk" screwdriver with my butane torch and then hold it on the screw?

Nucejoe Distinguished Member

Nucejoe

Posted
Posted

You probably haven't given enough time for the oil to penetrate.

Try this.

Remove the balance cock assembly.

Remove balance the jewel on mainplate side.

Remove the fork.

 Drop the rest in Coca Cola for a 48 hrs soak.

Good luck

  • Like 2
Marc Distinguished Member

Marc

Posted
Posted
1 hour ago, signcarver said:

I think the 1002 ratchet screw is RH thread.

Be careful. I have just checked on two AS 1002's and in both cases the ratchet wheel arbor screw is LH threaded.

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mikepilk Distinguished Member

mikepilk

Posted
Posted

As Nickelsilver says, AS do tend to use LH thread on both crown and ratchet wheels.

I make a note on the pics I make during disassembly, for future reference. This is a AS984

Barrel-0004.thumb.jpg.ef7107b86d2ca257330284014458ee1a.jpg

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nevenbekriev Distinguished Member

nevenbekriev

Posted
Posted (edited)

Yes, this is common for old AS movenents. The screws, actually, are the same, and can be replaced by each other.  They used only one machine to make the screws, that's for economy.

I can't imagine that the click will work in reverse, that is silly thought. Unless it is on the crown wheel,  not on the ratchet wheel.

Edited by nevenbekriev
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signcarver WRT Addict

signcarver

Posted
Posted

@Nucejoe Thank you! Soaking now.

@mikepilk Thank you. 

- I have seen the AS 984 and AS 1002 mentioned together as if they are interchangeable but i know the mainplates, ratchet wheels, and crown wheels are different per the pictures below. So, is it possible that the threading on the ratchet wheel screws are different? I'm soaking the donor in Coke so i'll try it again tomorrow.

 - The watch i am working on is marked AS 1002 on the mainplate (see second picture below). Note that both the ratchet wheel and the crown wheel on the original watch are smooth (no circular groove around the screw.)C3141967-88B2-4FBC-8B70-5EE62A5DFE62_1_105_c.thumb.jpeg.21a7136236466e82665e1080fac809f2.jpeg

Mainplate of original watch, clearly marked AS 1002

77E1009F-E0A2-4130-9C32-241E95EBD99D_1_105_c.thumb.jpeg.a2815a802d3b4f3199c1054f20e13dee.jpeg

Donor watch below - The donor watch was advertised as a 1002, but i believe it is a 984 (there are no markings and the mainplate is different from my original watch. 

Note the circular grove around both the ratchet wheel and crown wheel.E75EC251-B3D4-4D7E-98F8-1EB9350C852F_1_105_c.thumb.jpeg.e3f665d05e24d5e26b924c2dc21f3d6e.jpeg

No markings on the mainplate AND the mainplate is different from the original watch.

41C85D85-F6DA-407D-8CFF-64EA62B29BA3_1_105_c.thumb.jpeg.2b341e8283f3f9c60d3195f3c8aae64e.jpeg

 

signcarver WRT Addict

signcarver

Posted
Posted

Updates:

@Nucejoe Coca Cola soak worked! Got the screw loose. Thank you!

@mikepilk You were right. The ratchet wheel screw and crown screw are both lef handed threads. Also, upon further disassembly of the donor, which i couldn't do until i got the ratchet wheel screw loose, i found a marking on the donor that says AS 1002. It wasn't in the same place as the original, but it was still there. 

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Nucejoe Distinguished Member

Nucejoe

Posted
Posted (edited)
18 minutes ago, signcarver said:

Updates:

@Nucejoe Coca Cola soak worked! Got the screw loose. Thank you

Popcorn now ?  

Soak balance cock assembly , to loosen two little scrws that hold the upper balance capstone. You be amazed how easy they unscrew.

Edited by Nucejoe
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