Hi,

I have a 167.005 connie I am trying to assemble. In fact, I am nearly done, after quite a long period of parts searching.
Anyway, my watch just came back from the shop, were I was told that my sweep second pinion is slightly bent and needs replacing in order to install the sweep second hand.
I have already figured that I need part no. 1253, but then I got a little confused: I have learned that there are different types of part no. 1253, and I am not sure which is fitting my caliber. A little bit of research showed that since there is a small "1" under the Omega symbol on the mechanism, I might need part 1253B, but I can't confirm this. I can only assume there are no different ss pinions for 551 movements.

Can anybody resolve this matter? Is there an on-line database for Omega movement parts?

Thanks!

 

Bump.
Old Omega catalog says 550-1253, other places - 550-1253B (474mm). Found 560-1253B on the bay. Is it initially the same part? Any other helpful info?

 

Hello - okay I have explained this before, but most movements come in different variations with regards to hand heights. In this case, the Cal. 551 appears to be available in 2 hand heights - H0 and H1. This means there are 2 different sweep seconds pinions available for this watch, so you need to determine what hand height your movement is to select the correct pinion.

The easiest way of doing this is to have your watchmaker measure the overall length of the sweep seconds pinion - even if it's bent he should be able to get a good enough measurement to make sure the correct part is ordered. I'm a little surprised he doesn't know all this already actually, and it's a pretty common thing to deal with...

Also, these pinions can be straightened if the bend is not too bad and you know what you are doing...but on with the specifics:

The Omega Extranet lists the H0 pinion as 5.09 mm long, and the H1 pinion as 4.74 mm long. However I am skeptical of this since usually H1 is longer the H0, not the other way around. So this might be a typo, but regardless if you measure what you have you can order the right part or your watchmaker can anyway.

The 5.09 mm pinion is part number 72205601253, and the 4.74 mm pinion is 72205501253B.

Note for your reference that the cannon pinion (where the minute hand mounts) and hour wheel (where the hour hand mounts) will also be different heights depending on the version of the movement - H0 or H1.

Cheers, Al

 

Thank you!
I guess I should measure it myself and see if it's just a little under 5mm or a little more.