how do I install the double corrector in a 7750-GMT movement?

[scoobs1971]

After replacing a faulty double corrector on a 7750-GMT movement, the quicksetting for date and GMT sometimes work and sometimes the double corrector doesn't seem to engage with either the DW or the GMT gear. It's like the spring isn't properly connected to the double corrector to put it back in place.

I also suspect the double corrector to work a bit different than on a standard 7750, so I have no reference on how to install it properly.

Does anyone have a picture showing how to install the double corrector and connect it with the spring attached on the date plate?

In what order do I install the date plate, DW, GMT gear and double corrector?

[capice]

Wow Pat, wish I could be of help here m8, otherwise you have to wait for Koln, maybe Taka can adjust this....before the drinks ofcoarse

[scoobs1971]

Wow Pat, wish I could be of help here m8, otherwise you have to wait for Koln, maybe Taka can adjust this....before the drinks ofcoarse

It's the eaxct same part as Taka and I worked on for hours the last time, so I hoped somebody could instruct us better...

[takashi]

I am very very interested to know too... On this piece it looks like to be pretty different. This part simply couldn't fit. We tried both ways to open the top plate, install it (didn't work) and open just the retainer plate for this double corrector and datewheel, also didn't work.

[scoobs1971]

I am very very interested to know too... On this piece it looks like to be pretty different. This part simply couldn't fit. We tried both ways to open the top plate, install it (didn't work) and open just the retainer plate for this double corrector and datewheel, also didn't work.

I now got the double corrector from another broken 7750 GMT, but still can't get it to work

But then again, this part could be the broken part, lol.

[ajoesmith]

Post some pics of the problem and we can all try and fix it for you guys!

THe more brains working on it the better!

EDIT: by the way whats a 'double corrector'? I might know it to see just dont know the correct terminology

[scoobs1971]

EDIT: by the way whats a 'double corrector'? I might know it to see just dont know the correct terminology

The double corrector is the 'star' wheel that engages with either the date wheel or with the wheel sporting the GMT hand when setting the crown in the 2nd position.

I'll try to make a pic somewhere this week.

[ajoesmith]

The double corrector is the 'star' wheel that engages with either the date wheel or with the wheel sporting the GMT hand when setting the crown in the 2nd position.

I'll try to make a pic somewhere this week.

Is it the gear next to the date '18' in this pic?

[scoobs1971]

Is it the gear next to the date '18' in this pic?

Yes it is. On a regular 7750 it changes between day and date setting. On a GMT the day wheel gears have been replaced by the GMT gears.

Takashi already found out that it's exactly the same part as on a regular 7750, so I must be doing something wrong when installing this star wheel vs the little spring which enables switching between GMT and day setting.

[scoobs1971]

Post some pics of the problem and we can all try and fix it for you guys!

It took some time, but finally I've made some pics of dissassembling the GMT module. See first post.

[Drulee]

Scoobs or Takashi, did you ever find the solution to this problem?

EDIT: And thanks for posting those pics. I just wish I'd found this thread yesterday - it would have saved me a few frustrating hours of tinkering.

[Drulee]

I guess it is too old a thread for those who participated to remember the fix ??

[Drulee]

After further examination of the double connector and the date platform, I believe the connector may be positioned on the wrong side of the wire/rod attached to the bottom of the platform. I know that some PAM A7750 movement platforms may be missing the wire, but it is present on this GMT one, so perhaps this is what needs to be looked at ??? Just typing out loud here

[Drulee]

Just to update, the double corrector has to have the turned down notch, on the right side of the plate, placed above the wire/rod (which is attached to the date platform) in order for it to work properly on my GMT A7750. However, I am now back to the "slipping" problem I started with - where after turning the crown to set the date, the DW will stop advancing and the gold star cog on the double corrector will seem to "slip". I'm fairly certain this is happening because of a worn down tooth, or teeth, on the intermediate setting wheel, or setting wheel, or other cog ????