Help With 2836 Problem

[DJT2]

Hi guys I'm finally up & running with my little workshop & my equipment so far outways my abilities lol.

I've just cleaned & rebuilt a cheap Chinese 2836 & transplanted the GMT function onto it. Everything went well apart from loosing the blasted click spring. However, I digress. The issue I'm having is.. When the movement is outside the case all works well, I can set the time move the date & gmt hand etc. Once I place the movement in the case & reinsert the stem. I can move the date & gmt, but when I fully pull the stem to the hand setting position. It starts to move the hands then the cogs start slipping as if there not meshing together correctly. Then as soon as I remove the movement from the case it all works fine again. Any advice would be greatly appreciated.

[Horlogerie]

My first thought is that the stem case hole and the movement stem hole are not lining up when the movement is installed in the case. The tolerance is very tight on alignment between the case and the movement.

Is the movement original to this case, in other words is anything different now than before you installed this new movement?

Also, adding a GMT function to a non-GMT movement could cause a height problem on the dial side where the original clearances were for an hour wheel only, not a GMT and hour one, so it could be that the dial is pressing down on the GMT and hour wheels and causing them to jam up.

How tight are the case clamps pressing down and holding the movement in place, you could try with no case clamps installed and see what happens, that may help isolate the defect.

[DJT2]

My first thought is that the stem case hole and the movement stem hole are not lining up when the movement is installed in the case. The tolerance is very tight on alignment between the case and the movement.

Is the movement original to this case, in other words is anything different now than before you installed this new movement?

Also, adding a GMT function to a non-GMT movement could cause a height problem on the dial side where the original clearances were for an hour wheel only, not a GMT and hour one, so it could be that the dial is pressing down on the GMT and hour wheels and causing them to jam up.

How tight are the case clamps pressing down and holding the movement in place, you could try with no case clamps installed and see what happens, that may help isolate the defect.

Thanks for the quick response. I have to admit that I previously had the movement in a different case & if I remember correctly it had the same issue. I'll try without the movement tabs & report back.

[DJT2]

Found the culprit. One of the cogs in the motion works had decided to come apart. replaced with a spare I had & all is well. Thanks

[Horlogerie]

Wow, don't see that type of failure too often.

You may want to check the cannon pinion friction in case it's really tight and may have contributed to the failure.

[DJT2]

Wow, don't see that type of failure too often.

You may want to check the cannon pinion friction in case it's really tight and may have contributed to the failure.

Good idea. It's all back together now & running like a champ. If I have any further issues with it, that will be the first place I'll check.