View Full Version : SW200 Ratchet Wheel Replacement

11-08-2015, 05:34 PM
Some of you may know, some may not, when Sellita first introduced the SW200 automatic movement there some issues. One of the more common issues that people ran into was with the gear teeth shearing off on some of the wheels/gears. Both the design of the teeth and the strength of the metal used were causing the issues. With the introduction of the SW200-2, these issues were addressed and resolved.
This is the issue with one of my older SW200 movements. Several teeth sheared off of the ratchet wheel, in two different locations on the gear.
Without getting all crazy technical, I will try to give a brief explanation of the parts that are included in this repair.
The ratchet wheel sits atop of the barrel, which in turn houses the mainspring. The mainspring stores the "energy" that is used to power the movement. The ratchet wheel is turned by two different sources in an automatic movement, the crown wheel and automatic winding module. The crown wheel receives its power from the crown when the movement is manually wound. The automatic winding module receives its power from the rotor/oscillating weight.
So, when the watch is manually wound with the crown, the power/energy is transferred from the person winding the crown to the crown wheel to the ratchet wheel to the mainspring, where it is stored and ultimately released to run the movement. When the watch is wound, via the rotor, the power/energy is transferred from the person wearing/moving the watch to the rotor/oscillating weight to the ratchet wheel to the mainspring, where its is stored and released.
With the sheared and broken teeth on the ratchet wheel, it was difficult and dangerous to manually wind the movement. I could feel the "slip" of the gears as the crown wheel made contact(or lack of contact) with the broken teeth.
Finding parts for the SW200 is not very difficult, as most are interchangeable with the ETA 2824 and other "clone" movements.

This is a fairly simple and straight forward repair. Fortunately, I was able to keep the movement in the case for this repair, as only a few parts needed to be removed and all of these parts are easily accessible through the case back. A few very important things to keep in mind...
USE THE RIGHT TOOL FOR THE JOB. If your screwdriver is too big or too small parts can get damaged, let alone the frustration.
USE PROPER LIGHTING. Do repairs in a well lit area, without carpeting. If a screw or other part drops onto the carpeting, you will NOT find it. Trust me

1-Remove the case back.
2-Inspect the movement for any foreign objects, like broken teeth from gear.
3-Remove the rotor screw and set aside. You may need to brace the rotor depending to prevent it from moving while removing the screw. If you do, take caution not to damage anything.
4-Carefully lift and remove the rotor. Keep the related parts together so you don't mix up screws or forget what goes where.
5-The automatic winding module is now accessible. There are two, small blue screws on opposite ends of this plate. These two screws hold the plate/winding module in place. Remove these two screws and set aside.
6-Carefully lift and remove the winding module/plate. You may need to GENTLY "pry" this loose.Again, GENTLY! There are gears attached to the underside of the plate that come into contact with the ratchet wheel, be cautious not to damage these gears or their teeth. Remember to keep the two screws, that hold this plate in place, with the plate and do not loose them.
7- Now the ratchet wheel and crown wheel are exposed. If the movement is running, you need to release any power from the mainspring. To do this, there is a small lever mechanism next to the crown wheel. This lever allows the crown wheel to turned, winding the mainspring, and prevents the reverse turning of it with the small post that engages with its gears. Using the tip of your tweezers or a small screw driver, push on this lever while slowly turning the crown counter clockwise. By holding and turning the crown, it prevents the rapid and dangerous release of energy from the mainspring, which could damage or break it. Once all of the energy is released and movement stops running, you can remove the ratchet wheel.
8-Unscrew the ratchet wheel screw and remove it. The wheel can now be removed. Be careful when doing this, it is in contact with the crown wheel and the gear teeth should be interlocked. Again, you may need to GENTLY pry the wheel up. Remove the damaged wheel and set aside.
Time to reassemble the movement.
9-Insert the new ratchet wheel carefully. Before attaching the screw, slightly turn the crown to ensure that the teeth of the ratchet wheel and crown wheel are engaged properly. Secure the ratchet wheel screw, being sure not to over tighten it.
10-Reattach the automatic winding module plate. Again, patience and precision. Align the plate, screw holes and gears, but DO NOT press down on the plate yet. The gears need to be in place and interlock with before securing the plate. As above, slightly turn the crown to allow the gears to line up and interlock properly. The plate should "fall" into place when everything is correctly in seated.
11-Secure the two blue screws that hold the automatic winding module in place. Do not over tighten. These screws are very very small and the threads can be easily stripped.
12-Before attaching the rotor, check the alignment and ensure that everything is working properly by manually winding the crown a few times. If there is no resistance, (other than normal), the mainspring is being wound, and the movement is running, than everything was assembled correctly.
13-Place the rotor on the automatic winding plate and align the screw hole. Attach and secure the screw.
14-Again, check and ensure proper winding and functions of the watch/movement.
15-Reinstall the case back.

Bam! A new ratchet wheel installed and a perfectly functioning timepiece again.....

All of the removed parts could and should be cleaned and lubricated prior to reinstalling them. As well, the gasket should be inspected and lubricated if need be.

Thank you for reading this long and boring post...

11-08-2015, 05:43 PM
http://i1307.photobucket.com/albums/s593/Scheels13/Mobile%20Uploads/IMAG0319_zps5euwtcoq.jpg (http://s1307.photobucket.com/user/Scheels13/media/Mobile%20Uploads/IMAG0319_zps5euwtcoq.jpg.html)

Here you can see the damaged ratchet wheel

And the new wheel to be installed


The automatic winding module/plate and rotor after being removed


SW200 with automatic winding mechanism removed and ratchet wheel exposed

http://i1307.photobucket.com/albums/s593/Scheels13/1446913575908_zpsizk0k9vc.jpg (http://s1307.photobucket.com/user/Scheels13/media/1446913575908_zpsizk0k9vc.jpg.html)

Damaged ratchet wheel removed. You can see where the teeth are missing, around 12 o'clock and 4 o'clock
http://i1307.photobucket.com/albums/s593/Scheels13/1446914132868_zpsuop28pz1.jpg (http://s1307.photobucket.com/user/Scheels13/media/1446914132868_zpsuop28pz1.jpg.html)

11-08-2015, 06:12 PM
First things first great job. I have a grand diver with a sw2)) and could feel the crown not winding the watch and called invicta and they told me I didn't need to wind the watch just shake it. I started laughing at him and demanded they fix it which they did. I never knew they had a wide spread issue with the movement. Thanks for sharing

11-08-2015, 08:16 PM
Great DIYer if one can... You are a brave man, my hands are too shaky for this kind of work.;)

11-08-2015, 08:53 PM
Great work and info!

Thanks for taking the time to post it.

11-08-2015, 09:44 PM
Thanks guys. I think it took long to type the instructions than it did to actually do the repair. You know, its only 4 screws that need to be removed.

11-08-2015, 09:57 PM
Excellent post. I've feared getting an original SW2)) because of this very issue but so far have only accumulated the -). Should I ever come across a movement with this issue, having your post in mind will surely help.[br]Thanks again.

11-08-2015, 10:05 PM
That's advanced. Good job!!!

11-08-2015, 11:08 PM
Wow, you are the man. Great post and toast.[img src=http://www.pic4ever.com/images/)28fs3)8)8).gif]

11-09-2015, 08:10 AM
Thanks for the lesson, nice job.

11-09-2015, 10:16 AM
Great write-up and photos! Thanks for sharing that with us.

11-09-2015, 11:31 AM
Another DIY success story. Thanks for sharing! :D

11-09-2015, 11:42 PM
Great Post thanks for sharing!

11-10-2015, 12:56 PM
Thank you for posting this cool DIY, and congrats[br]on a job well done.

12-01-2015, 02:04 AM
I actually need this for an Invicta I have. Thanks, I have been wondering what to do about it, now I can experiment.

12-01-2015, 02:32 AM
I actually need this for an Invicta I have. Thanks, I have been wondering what to do about it, now I can experiment.[br][br][br]If you have any questions or need any help, let me know. Good luck

12-01-2015, 05:59 AM
Sorry if I missed it, but how can I tell if I have one of these movements? I have a few SW2)) watches, but was unaware some were different.

12-31-2015, 06:38 AM
Again, acs2276 did this DIY, not "islesfan".

12-31-2015, 07:57 AM
Again, acs2276 did this DIY, not "islesfan".


01-05-2016, 05:30 AM
Some of you may know, some may not, when Sellita first introduced the SW200 automatic movement there some issues. One of the more common issues that people ran into was with the gear teeth shearing off on some of the wheels/gears. Both the design of the teeth and the strength of the metal used were causing the issues. With the introduction of the SW200-2, these issues were addressed and resolved.

. . . [unnecessary portion deleted]

Clarification and correction. There is no Sellita SW 200-2 (as of January 2016). The current revision is the 200-1, per Sellita's web site and documentation dated 2 February 2015:

Sellita technical specs for the SW 200-1:
http://www.sellita.ch/images/stories/documents/SW200_1_33_20150226.pdf (http://www.sellita.ch/images/stories/documents/SW200_1_33_20150226.pdf)

The "-1" revision was implemented 19 August 2008 per Sellita's technical documentation regarding the revision:

Obviously, whether a 2008 watch has the "-1" revision or not requires looking at the movement. I wouldn't presume a watch made in 2009 would have a Sellita SW 200-1 inside either, as watch makers would usually exhaust existing stock (I've got two Bulova Accutrons that do, but only know year, not month).

Sellita started marking the movements on the edge of the plate under the balance wheel rim while they were still making the SW 200 (when I'm not certain), but it was before the "-1" revision. If a movement isn't marked, it's an SW 200. If it is marked, it will have an SW200 or an SW200-1. You can tell if it's the "-1" revision by looking at the marking. It's very small, requiring a loupe, and can be difficult to read through a display back requiring working with a light to illuminate the edge of the movement.

This one - inside an Oris - is a SW 200-1, and you can just barely make out the "-1" in the marking, but it's there. The ones in my Bulova Accutrons looked similar.