Question about Swiss part numbers

[Barnaby]

I need to replace the date indicator driving wheel on a FHF 90.5. The part number is 2556. Cousins have most of the parts for this movement, but they have two date indicator driving wheels: one with the number 2556, listed as out-of-stock (obsolete), and one with the number 2556.1 (in stock). Unfortunately no pictures.

So what's the difference between 2556 and 2556.1? Which one do I need?

[saswatch88]

i wouldnt know but couldnt you call cousins and ask, they should know for sure

[watchweasol]

Hi    you could try comparisson sites, AG Thomas, Gleave and co, Dr Ranfft for tech details etc, Esslinger in the USA . Have a look on Cousins PDFs for the FHF 90.5 Tech sheet or Gleave & Co on their tech  hub for further information. All available on the web.

[Barnaby]

5 hours ago, saswatch88 said:

i wouldnt know but couldnt you call cousins and ask, they should know for sure

They have this policy:

 

"Due to the specialised nature of the industry and the variables with customer specific applications we are unable to provide individual technical advice on your requirements. Our website does provide all information to enable customers to identify and select their specific requirements.

If you need technical help we recommend you seek the assistance of a trade professional."

[StuartBaker104]

Not many clues in the usual places on this question, funny enough though, I note that Watchguy, Gleave and Cousins all have the same hand made annotation on their parts sheets!

Most likely they are interchangeable and the 2556.1 is just an upgraded version.

By the way, if your German is up to scratch, this might interest you. If not, then just the oiling charts might be of use http://forum.watch.ru/attachment.php?attachmentid=952077&d=1426676161

[rogart63]

Could be that the 2556 is for the 90.5 and the 2556-1 is for the 905 . Have some 90.5 and 905 movement can have a look if i have the part.   On the one i found is a plastic part that i think would easily break. Don't know if it's a 2556 or a 2556.1

[rogart63]

Think i could be right . If i look at the 90,5 at Jules they use the 2556 . Couldn't find it on the 905 but the 909 use the 2556/1 . 

[Barnaby]

3 hours ago, rogart63 said:

Could be that the 2556 is for the 90.5 and the 2556-1 is for the 905 . Have some 90.5 and 905 movement can have a look if i have the part.   On the one i found is a plastic part that i think would easily break. Don't know if it's a 2556 or a 2556.1

I had assumed that the 90.5 and the 905 where the same movement, just that some people forgot the dot!

[Barnaby]

4 hours ago, StuartBaker104 said:

Not many clues in the usual places on this question, funny enough though, I note that Watchguy, Gleave and Cousins all have the same hand made annotation on their parts sheets!

Most likely they are interchangeable and the 2556.1 is just an upgraded version.

By the way, if your German is up to scratch, this might interest you. If not, then just the oiling charts might be of use http://forum.watch.ru/attachment.php?attachmentid=952077&d=1426676161

Thanks for the service manual, I don't know any German but it's still useful.

 

The part I need to replace looks like the one in that manual- i.e. a smiley face.

[rogart63]

3 hours ago, Barnaby said:

I had assumed that the 90.5 and the 905 where the same movement, just that some people forgot the dot!

Don't know why. But if you look at ranfft there is a 90-5 and a 905 . They look to be the same? But have seen both 90,5  and 905 printed on the bottom plate. So i guess maybe one of them is an updated version . http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&2&2uswk&FHF_90_5

[Barnaby]

UPDATE:

I bought the part (the 2556.1) and it is exactly the same as the original. (The movement is a FHF 905, not a 90.5).

Unfortunately it hasn't resolved the issue- seems to be something funny going on with the date jumper...

[rogart63]

15 minutes ago, Barnaby said:

UPDATE:

I bought the part (the 2556.1) and it is exactly the same as the original. (The movement is a FHF 905, not a 90.5).

Unfortunately it hasn't resolved the issue- seems to be something funny going on with the date jumper...

What about the date jumper? Lost the little gear on the stem? 

[Barnaby]

No, I already got a new one of those as it was missing when I opened up the watch.

It turns out the end of the date jumper spring was turned up slightly, and catching on the underneath of the date guard plate. This was stopping the date jumper from operating properly. I've trimmed the end of the spring and now everything works.