Wristwatch restoration, servicing and repair

Posts Tagged ‘Seiko Bell-Matic’

Seiko 4005-7000 (27J Bell-Matic)…

I’ve written quite a few posts about Bell-Matics and their calibres, but it’s been well over a year since one appeared on the blog. This one however is somewhat rare, and in some respects is the missing chapter of the story.

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What makes this Bell-Matic stand out from the crowd is that it has a date only calibre, the cal. 4005A, rather than the day/date cal. 4006A found in the majority of Bell-Matics.

The date only models were produced in the early days of the production cycle, and only for a couple of years before being phased out.  Only two models were available, the subject of this post (also available with a blue dial) and this one, available with either a black or white dial.

The cal. 4005A was only available in a 27 jewel version and like all Bell-Matic calibres, the jewel count is clearly displayed on the winding rotor, and the calibre number on the winding bridge.

The main difference between this calibre and the 4006A is of course the calendar mechanism. With the dial removed, comparing the two calibres you can see that the advancing wheel and day jumper found in the 4006A are missing from the calendar plate on the 4005A.

In terms of other differences, the unlocking wheel has no raised boss for the day disc, and the date ring is not as deeply recessed as no additional space is needed to accommodate the day wheel.

Other than that the calibres are identical from a technical perspective, but there are subtle differences in the case designs for the two model lines. The date only models use a different crystal for example.

Although running on arrival, this Bell-Matic had ‘lost it’s voice’. The alarm wouldn’t wind up any more, which all pointed to either a problem with the crown wheel or a broken alarm mainspring.

Sure enough, the problem turned out to be broken alarm mainspring, so with that replaced and the rest of the movement serviced, it was back up and running again.


** Many thanks to Neil Lever for letting me feature his watch on the blog. **

Seiko 4006-6011 (17J Bell-Matic)…

I was very surprised to be the only bidder on this, one of the more popular 17 jewel Bell-Matics…

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The watch didn’t run, needed a new crystal and was missing it’s stem and crown, but I think it must have slipped under the radar of my usual Bell-Matic competitors, so I was delighted to snap it up for a very reasonable opening price.

On arrival I was even more pleased as the dial and hands were near perfect, the case had no corrosion at all, and the movement was spotless… it even had a casing spring! The only down side was that one of the dial feet had been snapped off.

I’ve had quite a few Bell-Matics with broken dial feet now which is odd, as I rarely see it on other watches. The only thing I can think of that would cause it would be a very heavy knock, but then I’d expect to see other damage too, broken pivots or balance staff for example. Whatever the reason, with a dial in this condition it was certainly worth the extra effort involved in fixing it…

I’ve given up trying to figure out which Bell-Matic dials have a built in spacers as there seems to be no pattern to it at all, but luckily this dial was one of them so drilling out the old dial foot and making a new one was pretty straight forward. (I’ve posted about fixing dial feet before, click here if you missed it.)

With the dial repaired, I found a suitable crown and stem in the parts box, then a clean and oil for the movement and a new crystal finished the job. There’s no doubt about it, Seiko make a great blue dial, everyone should have one…


The Seiko Calibre 4006A (21 Jewel)…

Early in 2007 I wrote a post comparing the 17 jewel and 27 jewel Bell-Matic calibres, at the end of which I mentioned the rarer 21 jewel version (read that post here). While I’ll admit I haven’t been searching tirelessly, I finally managed to get hold of one, a 4006-7019 from 1967…

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It was in a sorry state that’s for sure, but I was more interested in the movement this time.

In keeping with the other Bell-Matics calibres, the number of jewels is clearly printed on the winding rotor…

With the winding rotor and mechanism removed, you can see that the 21 jewel version has extra jewels for the third and fourth wheel pivots, just like the 27 jewel version. (Notice that this movement also has one of the extra long sounding springs only seen on really early models).

From what I’d read, I was expecting to find extra jewels on both sides of the calibre; two jewels on the barrel and wheel train bridge, and two jewels on the calendar plate under the date ring. However, that isn’t the case as the two remaining extra jewels were quickly revealed by removing the ratchet wheels for the mainspring and alarm spring barrels…

This means that the 21 jewel version shares the same barrel and wheel train bridge as the 27 jewel version with the 4 extra jewels…

With all the extra jewels uncovered I wasn’t expecting any more surprises, but there was one waiting on the dial side, the calendar plate was gilded…

I’ve never seen this before on any Bell-Matic… can this be specific to the 21 jewel version? With the calendar work removed, you can see that the calendar plate does not have any extra jewels under the date ring so, apart from the gilding, it is exactly the same as the calendar plate on the 17 jewel version…

Unfortunately there isn’t an ‘all finished up’ picture this time as the watch had been literally blasted with oil, flooding the case completely. Check out the dial… that’s pure oil on there!

The dial print was actually floating in the oil, one push and it slid right off. Nasty!


Seiko 4006-7001 (17J Bell-Matic)…

It’s been quite a while since I’ve restored a Bell-Matic, but this non-runner certainly looked like it had some potential…

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As you can see in the picture above, the crystal was in need of replacement, but when I removed the bezel it was obvious that someone had tried (and I mean REALLY tried!) to remove the bezel in the past…

… It was like that almost all the way around, what were they using, a hammer and chisel?

I’m guessing that when the bezel finally popped off and they realised that the crystal didn’t just lift out, the bezel was replaced, and into a drawer it went. The movement obviously hadn’t been running for a long time as the oils had all dried up, but when cleaned and re-oiled, it ran nicely.

Thankfully the damage to the case didn’t affect the seating of the crystal or the bezel, so after the movement was serviced it was just a matter of fitting a new crystal and doing some ‘damage limitation’ on the case. Here’s the watch all finished up…

On really close inspection the case still has a few battle scars, but with a dial and hands in such great condition, I can certainly live with that.


Seiko 4006-6031 (17J Bell-Matic)…

I picked up this very sorry looking Bell-Matic with a badly scuffed up case and crystal, and showing all the signs of damaged dial feet. Looking past all that though, the hands, dial and alarm bezel looked great, plus all the original lume was still intact.

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On taking the watch apart I was surprised to find that the dial had a built in spacer. I’ve always assumed that it was only the 700x series of Bell-Matics that had this kind of dial. Sometimes it’s great to be wrong!

As I’ve described in a previous post, it’s possible to replace the feet without soldering on this kind of dial, as the old ones can be drilled out and new ones can be made and fitted relatively easily.

With the main problem solved, a movement service, a new crystal and quite a bit of work on the case finished the job…


Seiko 4006-6031 (17J Bell-Matic)…

I already have the blue dialled version of this watch, but this one looked too good to miss. Although not running, it showed great potential with a near perfect dial, alarm ring and hands.

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Only a short post this time as there were no hidden surprises with this one. A movement service, a new crystal and a once over for the case was all that was needed to add another great watch to the collection…


Seiko 4006-7000 (27J Bell-Matic)…

I rescued this survivor from the bay, the lume looked clean and I hoped that the rest of the dial was in good condition under the damaged crystal.

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Regardless of its condition, the dial was skewed in the case meaning that both dial feet had been broken off, so I knew it would need some extra work.

The good thing about the 700x series of Bell-Matics is that, unlike most watches, rather than having an independent spacer under the dial to provide clearance for the day and date rings, a metal spacer is fixed to the back of the dial instead. This means that broken dial feet can be drilled out, new feet made, and reattached.

When making new dial feet it is important to make sure that they are the right length, as the day wheel is only held in place by a dial washer under the dial on Bell-Matics. If the dial feet are too long, the dial will sit too high and the day wheel won’t be pressed down enough to engage with the day change mechanism.

Here is a picture of a new dial foot in place (and inset is the 0.5mm drill used to remove the old feet alongside a match… small stuff!)

Here’s the watch after the dial repair, a movement service, a case polish and a new crystal, it’s quite a transformation. It’s hard to describe the colour of this dial, in some lights it looks silver and in others it has a blue hue…. in either light it looks good!


Seiko 4006-6040 (17J Bell-Matic)…

Up and running again and first in line, another Bell-Matic. This time one of the more popular integrated bracelet models with a great blue dial.

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I bought this one on eBay without seeing a movement picture (I like a gamble!) and was pleased that the movement, though not working, was in decent condition. The watch did have a few cosmetic issues that would need to be put right though, the caseback was wrong (a -6031), the bezel had a large dent in it, and the crystal didn’t fit at all. I also had my suspicions that the hands weren’t right, but I’ve seen this model with several different styles, so I decided to leave them as-is for now until I know for sure.

I had my doubts about the originality of the bracelet too. Though the fit and finish matched the case perfectly, the -6040 is more commonly seen with a different stlye of bracelet. However, a bit of digging turned up this old Seiko brochure which shows a -6040 with the same bracelet, so that was good enough for me.

If you’re looking to buy an integrated bracelet model, it’s worth paying particular attention to the bracelet, as a regular strap can’t be fitted to this style case. Seiko’s stock of replacement bracelets ran out years ago and there isn’t an aftermarket alternative, so you’ll see some real disastrous ‘work-arounds’ out there on the open market.

I knew before I bought this one that I had a good -6040 caseback and bezel from an old parts watch which I could use, so a once over for the movement and a new crystal finished it off.