Seiko 7005 Date Wheel Alignment

[Kingsie]

Hello forum,

I posted on here a few months ago about my first ever attempt to service a watch, a Seiko 7005 to be specific. You correctly advised me that I required a new click

I have now sourced a new click and I am continuing with the rebuild. I'm now working on the calendar side of the movement

I am encountering an issue which I hope someone can clarify. The date wheel is misaligned when it is advanced automatically, i.e. not using the date change setting on the crown. When I inspect the movement closely I see that the date jumper spring isn't quite sitting in the right place on the date wheel (see photo). You can see that it doesn't quite sit properly between 16 and 17. When I manually tweak the jumper's position using tweezers the date wheel will align correctly but, alas, when the date advances again the misalignment problem will return. As a rookie, I can't fathom out what must be going wrong for the jumper to always end up in slightly the wrong place

When I set the jumper in the first instance, I ensure it sits properly against the date wheel. However the date advance finger seems to be throwing it off somehow

Can anyone help me out?

Thanks

[watchweasol]

Hi  so when you advance the date manually its ok and indexes correctly, yes.  but not when working on its own power,  i should check the driving wheel and finger for wear. The detent spring and detent also for wear and lack of tension. I have attached the sheets for the 7005 and the 7009 as they employ similar systens.

277_Seiko7009A.pdf 3113_Seiko 7005A (1).pdf

[aac58]

You can also try lubricating the tip of the date jumper and the zone of the main plate where the date wheel rests (between 1 and 5 in your photo) (I use HP1300 there). Seiko not always recommend lubbing these areas, but sometimes they do, like in the step 12 of the 6106 assembly.

However, it should not be necessary.

Edited December 19, 2022 by aac58

[Kingsie]

When I advance the date manually it's fine. When I advance the date by advancing the time until it passes midnight I see misalignment, see second photo. This is caused by the date jumper not quite moving far enough, see first photo

I've looked at the date driving wheel and date finger under a loupe and they look fine. No missing teeth, no gunk between the teeth

Not sure how I check a spring for lack of tension. It seemed appropriately springy when I installed it, not sure if that's springy enough though

I also lubed the main plate between 1 and 5 as per aac's comment

I still get misalignment. I'm really not sure what's going on here

[watchweasol]

Probably the detention or spring,more likely the spring is set.

[Melt]

I would also look for a slightly bent tooth on the date wheel which can snag on the guard or maniplate.

[Kingsie]

3 hours ago, watchweasol said:

Probably the detention or spring,more likely the spring is set.

What do you mean by the spring is set? You think the spring isn't springy enough?

 

I've looked at the wheels under a loupe and they all look fine

[watchweasol]

The term” set” refers to the SPRING having lost its tension Or as you said it’s springiness. This also happens to mainsprings. Any spring under tension for a long period will eventually set. It also depends on the material the spring is made from.   But also as Melt mentioned check the rim of the date wheel for worn or damaged edges.

[Kingsie]

Thanks, watchweasol. My working hypothesis is that the spring is set. It's an old watch, so it makes sense

I'm not inclined to blame the date wheel since I've got two 7005 date wheels (one is from a donor movement) and neither will work properly

I've not got a spare date spring though, so I'll source another part and report back

[watchweasol]

Hi replacing the spring is the smart option and probably the cheapest one. Await the result

 

[lexacat]

Does the date wheel fail to turn correctly only when the dial is on? I've recently swapped dials on a couple 7009's and noticed that if not installed correctly the dial can press down on the movement and prevent the day/date from adjusting correctly. It was a matter of adjusting the dial feet/screws until everything moved clearly.

This might not be your issue, however, but could be worth investigating.

Edited December 29, 2022 by lexacat

[Kingsie]

Interesting thought, lexacat. I'm afraid the date wheel won't advance properly even without the dial

I'm working on the assumption above that the date spring is set. I'm still looking for a new date spring, not many ebay auctions running over the Xmas period

I will keep everyone posted

[watchweasol]

Hi Just a thought, check that the day star snap in not pushed down too far and distorting the plate. 

[Kingsie]

22 hours ago, watchweasol said:

Hi Just a thought, check that the day star snap in not pushed down too far and distorting the plate. 

What's a day star snap? The 7005 doesn't have a day wheel, just a date

[watchweasol]

Ok. The day star snap is a clip on the 7009 that holds the day wheel down and can sometimes impede its action if pushed too far.