How to Replace an Asian 21j Movement

[Francisco]

It is know that many times has no sense to repair a replica with an Asian 21j movement. The repair may be very expensive in comparison with the cost of the watch. The objective of this tutorial is to show how to substitute / replace an A21j movement. For that reason I bought a broken submariner from a colleague of a Spanish forum. Here follows a picture of this submariner.

The equivalent of the A21j to be bought is the DG2813. This movement can be obtain, for example, from Ofrei (USA) and Cousins (UK). Follow the links:

http://www.ofrei.com/page1119.html#16874

http://www.cousinsuk.com/catalog/4/40/1921.aspx

The DG2813 beats at 21600. The equivalent version beating at 28800 is the DG4813 (Ofrei) and DG8413 (Cousins, wrong name in this webpage). The DG2813 is very cheap: $15.40 at Ofrei,

[Jkay]

Thank you!

[bvall]

Some of the pictures is dead, it would be very nice if you fixed those. Just bought tools for doing this kind of stuff.

[devus]

nice...

[simon05]

Thank you Francisco, I don't yet have the experience or confidence to attempt repairs. But posts like these are very informative & educational. Well done.

[dakwan]

Some of the pictures is dead, it would be very nice if you fixed those. Just bought tools for doing this kind of stuff.

Agreed!

[gt rider]

How do you determine which a21j movement is in the watch? In order to know which one to order.

[Jkay]

How do you determine which a21j movement is in the watch? In order to know which one to order.

A21j is a name for Chinese clones of the Japanese Miyota family of movements. There are only two types: the high beat and the low beat. Does your seconds hand tick 3 times a second or four? That's how you know.

[gt rider]

A21j is a name for Chinese clones of the Japanese Miyota family of movements. There are only two types: the high beat and the low beat. Does your seconds hand tick 3 times a second or four? That's how you know.

How many different times of 21j movements are there?

[Jkay]

I'm not sure if you are being sarcastic?  The term "a21j" is used by almost everyone to refer to the two clones of the venerable Japanese Miyota (Citizen) 8125 movement. Ironically the Chinese improved the movement when they cloned it, and added a hacking function. The Japanese gen has no seconds hack.

 

The two Chinese clones of this movement that we call "A21j" are the 2813 and the 4813 .. they cost about $23 us dollars and are respectively a 21k beat and a 28k beat movement.

[gt rider]

I'm not sure if you are being sarcastic?  The term "a21j" is used by almost everyone to refer to the two clones of the venerable Japanese Miyota (Citizen) 8125 movement. Ironically the Chinese improved the movement when they cloned it, and added a hacking function. The Japanese gen has no seconds hack.

 

The two Chinese clones of this movement that we call "A21j" are the 2813 and the 4813 .. they cost about $23 us dollars and are respectively a 21k beat and a 28k beat movement.

I am trying to understand the differences. To be more specific, I'm wondering if there are different sizes of a21j movements. I have several a21j watches and I'm wondering if they are all the same size. Can I swap/replace any a21j movement with another? Is the only difference how much they beat?

[Jkay]

 Can I swap/replace any a21j movement with another? Is the only difference how much they beat?

 

The 2813 and the 4813 are identical except for the balance mechanism. If your watch has a higher or lower cannon pinion, then simply remove it from the old A21j and transfer it to the new one.