Datejust 16234 runs fast when I wear it

[Mer2112]

Hello All,

Just got my 17 year old Datejust back from its second service. First one was at 10 years (2009). Nothing wrong other than the silver tapestry face had tarnished very bad and was a brown/pink color and it was just due for a check up. Over the last year or so I noticed it was gaining time, 2-3 minutes a week. Did some reading/browsing and decided it was time to send it in again and see what's going on.

It received a new mainspring, axle, gears, gaskets, was regulated, pressure tested and sent back. I've attached the accuracy sheet showing the results. They look great to me.

When I wear it, it gains 25-30 seconds a day. Last night at 6:00 I took it off, wound it, set it and set it face up. This morning at 6:00 I checked the time and it was perfect, no gain or loss.

I'm going to test it in all the positions to make sure one specifically isn't giving odd results. I sit at a desk mostly at a computer. Nothing out of the ordinary. I'd say the majority of the time, the watch is crown left, tilted back at a 45 degree angle.

Any thoughts/suggestions?

I'm not mad, just curious as to why it does this when I'm wearing it.

Thanks,

Eric

[Jefferyasher]

Can you explain the position with the crowns left and right?

[Mer2112]

The remaining results were +1 for crown up and dead on for the remaining positions.

Tomorrow will be 1 week with no adjustments and so far it's gained 1 minute, 25 seconds in 6 days.

[Jefferyasher]

So crown up causes yours to speed up? I though Rolex says it should slow down. I've been keeping mine crown up and is runs +6 per day avg. after 8 days. Cannot find a good position to keep at zero and have tried many. What is the crown to right and left?

[Mer2112]

Yup, crown up and mine gains a second in 12 hours. I forgot to add, crystal down it gains 2 seconds in 12 hours.

If you're looking straight at the watch, crown right would be 12 in the normal up position, crown left would be upside down. (6 up and 12 down)

[Jefferyasher]

As such? Do you have it on a pedestal to keep it upright? Sorry for the numerous questions and lack of clarity. The pic should be rotated 90 degrees to the right.

[Mer2112]

Yes, rotate your photo 90 degrees to the right and that's crown right. Rotate it 90 degrees to the left and that's crown left. I used a plastic cup that fit my band just right and propped it up.

[Jefferyasher]

Thanks!

[SearChart]

Your amplitude is too high IMO, when the automatic module is placed and the watch is worn there can easily be a gain in 20 degrees amplitude as well, this would mean the roller jewel is going to hit the outside of the pallet fork. This can have a bad effect on timekeeping.
You could solve this by replacing the mainspring for a 315-2 'weak' mainspring.

[Mer2112]

Turned out to be a broken jewel. It would run perfect when sitting still but when subjected to movement, it would gain time. All fixed and on its way back to me.