# Seiko Chrono Crystal Problem



## tixntox (Jul 17, 2009)

I've just had the front of my Seiko quartz chrono (battery/quartz type) to clean it. There was a white nylon type ring under the crystal surround. It is a bit deformed and the fitting is loose without it. Any suggestions as to where to get one and how to fit successfully etc?

Mike


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## bry1975 (Feb 6, 2004)

Sounds like a Seiko 7A28 or 38. Can you provide the caseback details please need to know the ****-**** number, so say 7A38-**** etc etc

Regs

Bry


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## tixntox (Jul 17, 2009)

It's 7A38-7180 thanks.


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## bry1975 (Feb 6, 2004)

It appears that gasket is difficult to obtain.

Regs

Bry


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## bry1975 (Feb 6, 2004)

bry1975 said:


> It appears that gasket is difficult to obtain.
> 
> Best thing would be to ring cousin's it might be Seiko Gasket FH3181B01
> 
> ...


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## tixntox (Jul 17, 2009)

Thanks for the suggestions. I'll give them a try. Will the gasket make the bezel a good fit then? Mike


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## bry1975 (Feb 6, 2004)

It should do can you forward a pic of the actual watch.

Regs

Bry


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## tixntox (Jul 17, 2009)

Pic attached. Sorry about quality but I forgot to press the macro button! Doh!


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## tixntox (Jul 17, 2009)

Just noticed that the microseconds hand is one click out! Looks like I have another adjustment whilst the crystal is off.

Mike


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## bry1975 (Feb 6, 2004)

Yes it will sort the bezel looseness you will probably need a crystal/bezel press for this just take your time fitting the bezel. Don't touch the subdial hand, that is reset using the pusher buttons.

Move the crown to the date or hand setting position and press the pushers this will move the hands in 1 increment steps.

Regs

Bry



tixntox said:


> Just noticed that the microseconds hand is one click out! Looks like I have another adjustment whilst the crystal is off.
> 
> Mike


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## tixntox (Jul 17, 2009)

Spot on information Bry. Just done the hands. What a brilliant watch. Sold my Seiko 5 automatic last week as I got fed up of going through the restart routine when I didn't wear it and it stopped. No problems with this baby once the case gasket is sorted. Many thanks again. Mike :clap:


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## SEIKO7A38 (Feb 12, 2009)

bry1975 said:


> It appears that gasket is difficult to obtain.
> 
> Best thing would be to ring cousin's it might be Seiko Gasket FH3181B01
> 
> ...


The part number 'FH3181B01' that Bry is (erroniously) quoting you is the case-back sealing ring.

The *correct* Seiko part number for the bezel (to case) gasket for a 7A38-7180/-7190/-7270/-728X is *86178990*. It's orderable from the source that Bry quoted under the same part number (not always the case with C*****s UK - sometimes they prefix the Seiko p/n with 'SEI' - though not always). Price is Â£2.25 + V.A.T.

Even with a crystal press, you will find it very hard work pressing the bezel back on with a new gasket in place. They are bl**dy tight fit. Try lubricating it with a little Seiko Silicone grease. I also left the bezel in the freezer compartment for a couple of hours, to make it contract a little, before fitting.

If you need to replace the crystal, it might be a good idea to do it at the same time. I tend to re-use old crystal gaskets whenever I can, again simply for the reason that new gaskets make fitting a replacement crystal bl**dy hard work (because of the tight tolerances).

The company mentioned above also stock Seiko 7A38 crystal gaskets (and Sternkreuz alternatives). For 31.0mm diameter crystals, Seiko Black nylon gaskets (as you'd need for a 7A38-7180) are Seiko p/n *86565100*. Some of the Gold-plated 7A38's with 31.0mm crystals use a clear gasket between the crystal and bezel. That is Seiko p/n 86179152. As both of these are so hard to fit with a new crystal (even with a press), I've sussed out a slightly undersize alternative (I'm talking fractions of a millimeter), available from the same source. It's Sternkreuz p/n IG318310H. I ordered one last week, to try it out. Fitted a treat ! :clap:

If you have Excel on your PC, and are interested, PM me your eMail address. I have compiled 5 pages of Seiko 7A38 spare parts lists (for most of the common models), including several much cheaper 'alternative parts', and their sources. You may find it useful.


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## tixntox (Jul 17, 2009)

Many thanks. PM sent

Mike


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## bry1975 (Feb 6, 2004)

Hi ya,

Like I said I quoted FH3181B01 which is a hard back gasket, but was not 100% certain, Cousin's being lazy don't provide many part photos so it's easy to order a part totally different.

Regs

Bry


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## tixntox (Jul 17, 2009)

bry1975 said:


> Hi ya,
> 
> Like I said I quoted FH3181B01 which is a hard back gasket, but was not 100% certain, Cousin's being lazy don't provide many part photos so it's easy to order a part totally different.
> 
> ...


No problem. Thanks for responding. Much appreciated.

Mike


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## tixntox (Jul 17, 2009)

Just checked the timing over a day and it is spot on. Well, that's quartz for you. I'll be ordering the bits tomorrow. Many thanks people.

Mike


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## bry1975 (Feb 6, 2004)

Mike,

You do know the RAF chose to use that Seiko caliber!

The 7A38 and 7A28s are probably one of the best quartz chronographs ever!

Regs

Bry


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## tixntox (Jul 17, 2009)

Just awaiting the parts now. Thanks to all for your help and advice.

Much appreciated.

Mike


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