Omega Seamaster Chronograph Movement Lemania?

Northernman · Jun 27, 2017

mollydooker
Interesting , the above 1341 shows unidirectional part 1428 which is the rachet stop spring which is screwed on under 8500 Chronograph bridge and sits against the winding gear that meshes with the differential preventing it reversing.
I managed to source the correct winding gear from a lovely Italian gentleman who told me the 1040 would not work but as his English was limited I did not understand what he was telling me until it was too late.
Since restoration I wear it regularly and never had an issue and normal wear builds reserve quickly. EXCEPT , when I wind it (5 winds if from rest only) the rotor spins as well . Again the Italian gent told me to use plenty of lube on the winding gear but I did not understand what he was saying at the time.

1340 for comparison:

Northernman · Jun 27, 2017

I have checked with my 134x watches. My 1340s has 22 jewels. 1341s has 17 jewels, 1345 has 17 jewels.
However I have seen some watches where this does not seem to be consistent.

mollydooker · Jun 27, 2017

I have been looking carefully at photos of the Omega 1041 and Lemania 1341
And aside from the fact that the 1041 is 22 jewels everything seems identical except on the chrono. bridge of the 1341 there is a site hole ( beside chrono bridge screw hole) which is used to position the rachet spring stop against the winding gear whereas there is no such hole on the 1041 bridge.
Could it be that the 1341/5 is of a more rugged/ simple design .I know mine got lots of knocks and rough use yacht racing back in the day before mobile computers/gps and never missed a beat.

Northernman · Jun 27, 2017

mollydooker
I have been looking carefully at photos of the Omega 1041 and Lemania 1341
And aside from the fact that the 1041 is 22 jewels everything seems identical except on the chrono. bridge of the 1341 there is a site hole ( beside chrono bridge screw hole) which is used to position the rachet spring stop against the winding gear whereas there is no such hole on the 1041 bridge.
Could it be that the 1341/5 is of a more rugged/ simple design .I know mine got lots of knocks and rough use yacht racing back in the day before mobile computers/gps and never missed a beat.

I believe the 1341 and 1345 came some time (years?) after the 1340. The late 70s and early 80s was not a good time for the Swiss watchmaking industry, and cost savings would have had focus for sure!
Cousins UK marks the Omega 1040 and 1340 as "identical", but fails to mention the 1341 in the same comment.

Andy K · Jun 27, 2017

Northernman
I am interested in establishing this. The 1340 and 1341 versions of the movements are incorrectly identified by Ranfft.
Could it be that the 22-jewel versions is bi-directional winding, and the "budget" 17-jewel versions are uni-directional?
The 1345 is 17-jewels BTW.
Just a thesis, but it would be interesting to have it checked.

I have noticed a few inconsistencies with the Omega 1040/4041 families on Ranfft, especially concerning jewel count. The Ranfft page on 1041 is a bit confusing for two reasons - first, the photo shown is of a cal. 1040 movement with a service rotor, which is an odd choice but not uncommon for him to just use the base movement as the stock photo for entries for the entire family.

Second, on the left under "data" he describes it as 17 jewels but on the right he describes the cal. 1040 pictured and refers to it as 22 jewels. I had previously assumed the 17 jewels was just a typo or error in his data, but since a collector from NZ pointed out a 17j Speedmaster 125 to me it seems it could have certainly been intentional. That remains the only 1040 or 1041 I've seen with 17 jewels.

I would also love to know the winding direction of the 1340/1341/1345 - until this thread I never suspected a difference. I've never actually held a 1340 or 1341 🙁, I've been the second highest bidder a few times.

There is a downloadable PDF of the 1040 service guide at the bottom of this page, plus downloadable copies of the 1340/1 and 1345 parts guides.

Northernman · Jun 27, 2017

I have both 1340 and 1341s but not home until end of July.
Will definitely do some probing into this then.
Cheers.

mollydooker · Jun 27, 2017

I took the back off my watch and lay in position the old rachet stop spring on top of the chrono bridge . It screws onto the underside of the bridge and the spring sits against the teeth of the lower wheel of the winding gear preventing it moving ,in looking down on the back, clockwise . Again looking down on the back the rotor and winding gear rotate anticlockwise to wind the mainspring. The rotor ,gears connecting it to the winding gear and upper wheel of winding gear spin both ways .
Btw movement looks dirty but it's marking from being rusted up for years.

Foo2rama · Jun 27, 2017

Different jewel count for US market?

Andy K · Jun 29, 2017

Foo2rama
Different jewel count for US market?

That would make the most sense. However, I've only ever seen one 17j 1041 so it begs a lot of questions/possibilities:

Were there that few 1040/1041s shipped to the US?
Did Omega change their policy along the way (either starting with 17j to the US and then just shipping all 22j or vice versa)?
Was the 17j version for a smaller non-US market with even stricter import duties? (Did such a market even exist?)
Was that 17j bridge I saw an elaborate forgery of part from a non-Omega movement?

Omega Seamaster Chronograph Movement Lemania?

Northernman

Northernman

mollydooker

Northernman

Andy K

Northernman

mollydooker

Foo2rama

Andy K

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