The emergence of Grand Seiko as a high-end brand with staying-power took some time to resolve convincingly:  four years passed between the introduction of the first Grand Seiko in 1960 and its follow-up, the 57GS Self-Dater in 1964.  A further three years were to pass before the third generation Grand Seikos appeared: the automatic high-beat 61GS models and the low-beat 44GS three-hander, effectively the replacement of the original 3180.  However, in both cases, these new Grand Seiko-branded watches were adaptations or evolutions of, respectively, existing Seikomatic and King Seiko models.  There is the sense that the former was an opportunistic bit of badge-engineering whereas the latter was more complicated, tied up in the inter-divisional rivalry between the Suwa and Daini factories, and the ambitions of the latter for King Seiko to compete on level terms with Grand Seiko.  This confusion is neatly illustrated by the presentation of the opening ‘Top Quality’ section in the second edition of the 1967 Japan Domestic Catalogue:  two automatic 62-series Seikomatic Chronometers, captioned but not branded as Grand Seiko; the final iteration of the 57GS Self-Dater; and the King Seiko Chronometer 4420-9990 (formerly the 49999). 

The remainder of the King Seiko models at the time were relegated to other parts of the catalogue and priced at a level on par or below the mainstream Seikomatic models.  Clearly, this special chronometer-grade King Seiko was held in high regard in representing the pinnacle of Daini-division output at the time.  However, by the start of 1968, it became clear that the King Seiko brand was really only keeping the seat warm for Grand Seiko at the top table, whether as a placeholder or stalking horse depends on whether there had been any real strategic thinking of how to apportion plaudits between the two competing divisions.  Whatever the rationale, 1968 saw Grand Seiko asserting its preeminence with a clean sweep in its positioning at the top of the tree:  the two 62-series Seikomatic Chronometers were now branded as Grand Seiko, the 57GS continued, but in its penultimate appearance after five years in production and the King Seiko Chronometer of the previous year was quietly euthanised in favour of a brand new Daini-produced 44GS, featuring a refinement of the 4420 King Seiko movement in a B-variant. 

Effectively, the 4420-9990 had evolved into a Grand Seiko, with a new Taro Tanaka-designed case presenting the new Grammar of Design style that would feature as the signature Grand Seiko design for the next few years and form the inspiration of numerous Grand Seiko and King Seiko progeny.

The influence of the 44GS design-language was felt immediately with the replacement within the year of the multi-facet-cased 62GS models with the high-beat 61GS.  These new high-beat automatics were powered by a brand-new movement running at 36000 bph and housed in cases that aped precisely the design of the 44GS.

The 44GS was a landmark watch but was destined to survive for little more than a year. By the start of 1969 it had been replaced by a model that retained the same case design but which was powered by a brand new high-beat hand-wind movement, running at the same 36000 bph as the 61GS models introduced the year before.  The 45GS came with two movement variants, the 4522 featuring an instant change date calendar and the 4520, a simpler three-hander.  The much thinner hand-wind movement meant that the case had a stealthier profile than the full fat automatic high-beat 61GS but face-on, it’s really only the choice of polished dauphine hands for the purer hand-wind watches that distinguishes the two model lines. 

1969 arguably marked the point at which Grand Seiko as a brand really started to take hold, with the 45GS the fulcrum that inspired an explosion of innovative diversity in the range of Grand Seiko watches that were to follow in that brief but bright period before the onslaught of the quartz revolution put a temporary end to high-end mechanical watches as a breed.

This brings us neatly to the subject of today’s entry:  a gold cap Grand Seiko 4520-8000 from December 1970.

I acquired this watch as part of an auction lot of largely quite tatty but interesting watches, including two watches already featured on the blog (here and here).  This particular watch is one that, on first acquaintance, appears to reside at the tattier end of the spectrum and that impression is not exactly tempered by closer inspection.

The gold capping on the case is quite badly tarnished and whatever it is that is growing between the lugs is encroaching front side too, together with the beginnings of a healthy gathering of what looks like moss.

Appearances can be deceptive though and it doesn’t take too much effort to render the case looking a good deal more presentable, clearing the way to a first glimpse of the movement.

We are presented with what looks like a fine example of the 4520A Grand Seiko variant of the 25 jewel, high-beat hand-wind 45-series movement.  Aside from the different model number, there is nothing to distinguish this Grand Seiko movement visually from the King Seiko equivalent, an example of which we have met once before (see here).  The movement looks to be in excellent condition, barring a number of minor scratches and levels of patina commensurate with a lengthy period since its last service (although I would note that there were no service marks at all on the inside of the case back).  With a full wind under its belt, it sprang into life willingly enough but the timegrapher revealed a rather poor state of health.

Chronic amplitude, high beat error and running very slow.  We have arrived on the scene just in the nick of time.  A useful first step before extracting the movement from the case is to remove the Diafix cap jewel from the train bridge and the Diashock assembly from the balance.

It is also good practice to remove the balance at this point.

I am relieved to see that the balance hairspring looks to be in perfect condition, properly centred, symmetric and without any signs of previous watchmaker adjustments.  This bodes well for the ease with which the watch will be able to be regulated following the service.  Removing the movement from the case permits a survey of the condition of the dial and hands.

The hands look great and the dial is in largely very good condition, albeit with some signs of patination in places, particularly towards the edge between the 8 and 10 markers.  The rear of the dial displays the imprint 0N, indicating a manufacture date of November 1970, one month before the date suggested by the case back serial number.

The removal of the dial and hands affords our first view of the dial side of this three-hander movement, devoid of any of the machinery of the instant date change calendar we met in the King Seiko 4502.

Having removed the hour and minute wheel, a closer inspection of the pivots of the train wheels reveals a bit of a surprise:  most of the uncapped bearings appear to have been lubricated with heavy old-style Seiko S4 grease, laden with molybdenum goop.

Turning the movement over reveals the same choice of lubricant for most of the going train apart from the escape wheel, mounted as it is in the Diafix frame.

Disassembly begins in earnest starting with the ratchet wheel, then the pallet fork and its bridge.  Note the end of the two-part second setting lever poking out from beneath the train bridge adjacent to the N of JAPAN. 

Removing the train bridge reveals the route that the seconds setting lever takes from its point of interaction with the balance wheel, around the outer circumference of the main plate wrapping protectively around the third and fourth wheels.

It couples with the second setting transmission lever at this point, whose path continues beneath the barrel bridge before resting into the groove of the clutch wheel.

Where the gear train of the earlier 4420 comprised just four wheels (centre wheel, third wheel, fourth wheel, escape wheel, with power transferred in that order), the 4520 transmits its power from the barrel via a centre-mounted minute pinion, an intermediate wheel mounted beneath the minute pinion bridge, a large driving wheel and then the third wheel, fourth wheel, escape wheel and finally, centre seconds wheel.  Four wheels plays seven – that’s progress for you.  Here’s a closer look at the minute pinion and the intermediate wheel, the remaining members of the train having been removed.

You may notice the huge dollops of S4 lubricant, extravagantly slathered over the bearings serving the third and fourth wheels.

Regardless of the position you take over the choice of S4 to lubricate the gear train, this watch was massively over-lubricated at its previous service.  The final task in the dismantling of the movement is to deconstruct the keyless works.

The mainspring, once extracted from the barrel, has a good, healthy shape, sits flat and the barrel, inside and out, looks clean and free from excessive wear.

While the movement parts percolate, I can turn my attention to the case.  The 14k gold cap is sufficiently low in gold content to promote the development of patina with the passage of time.  I have to say that I rather like it and am in two minds about whether to remove it.

However, the case badly needs cleaning, and that process will inevitably remove, at the very least, a good deal of the patination so I may as well go the whole hog and subject the case to the usual round of pegwood, toothbrush and liberal doses of Colgate toothpaste.  The result belies completely my initial expectations about the extent to which this case could be returned to something approaching conventionally presentable.

I have one original Seiko 310T07ANG acrylic crystal left, and the case in its refreshed state absolutely deserves being treated to this precious commodity.

With the bezel pressed back into position with a satisfying click, the mid-case is ready to receive the movement once more, just as soon as that is assembled and running.

The crown on this model features a captured rubber gasket and as is almost invariably the case, the gasket fitted to this crown was hardened, flattened, and no longer fit for purpose.

There is enough clearance with these crowns to dig the old gasket out, but this requires the stem to be removed first.  Removing the gasket is not simply a matter of it easing it out as a whole, but rather requires an extended exercise in brutalist archaeology, the result of which is the transformation of the gasket from one piece into dozens of tiny fragments.

With that accomplished, I gave the crown a thorough clean and then fitted a fresh gasket following a couple of rounds of trial and error to find one that fitted snuggly.

I refitted the stem, set the case to one side, and turned my attention to the business of reassembling the movement, starting with the mainspring and barrel.  This being a hand wind movement, refitting the mainspring requires the hook at the end of the tail to achieve a nice snug fit into the machined recess in the wall of the barrel (indicated below).

One of the pleasing aspects of this movement is that it is not over-festooned with jewellery, with the number of jewels employed more or less appropriate to the task at hand (although I would have liked to see jewelled barrel arbor hole bearings in the mainplate and barrel bridge).  Only the escape wheel is equipped with Diafix bearings which makes my life slightly simpler.

The reassembly of the main plate componentry starts with the setting parts.

Turning the movement over, the going train can be pieced together, starting with the minute pinion, the intermediate wheel and the bridge.  Next comes the barrel, four of the remaining five train wheels and the two-part seconds setting lever assembly.  The barrel bridge comes next, followed by the train bridge at which point the crown wheel, click and ratchet wheel are fitted to the barrel bridge.

We are ready now to fit and lubricate the pallet fork.

The only thing standing between this as a static object brimming with potential energy and a ticking watch movement is the oiling, reconstruction and fitting of the dial-side Diashock setting, the fitting of the balance and its partner Diashock.

You can’t tell from the image above, but that balance wheel is swinging back and forth at a rate of 10 beats per second.  Initially, there was a fair amount of beat error but that was quickly dialed out and the movement pronounced fit to receive its dial and hands.  The remaining dial-side parts need refitting first, starting with the cannon pinion, and followed by the minute wheel, its guard, the hour wheel and finally the copper film washer (the latter not shown in the photo below).

With the dial and hands fitted, I check the timekeeping once more before moving on to reuniting movement with case.

It feels good to see that lovely movement settled once more into its plush home surroundings.

At this point, the movement is correctly aligned, the movement spacer dropped into position and the crown and stem refitted.  The movement and its spacer are secured by fitting the two case clamps.

With the movement in its operating environment, I performed a final timing regulation.  I placed the circular case spring loosely into the channel around the inner diameter of the movement spacer ring and fitted and tightened down the case back, complete with a fresh gasket.  At this point, I mounted the watch onto the timegrapher microphone holder for a final round of timing measurements before declaring this one finished.

The performance of this movement, whilst not hitting particularly spectacular amplitude heights, does nonetheless display comfortably the most consistent set of timings over four positions that I have been able to achieve in any watch I have worked on.

I could probably nudge the rate up a touch to get it running at +1 s/d over all positions rather than probably slightly on the slow side of 0.0 s/d but I am just happy to see it seemingly so unperturbed at its orientation.  In any case, it is likely that the rate will rise with decreasing power as the watch winds down during the day so this is probably a good compromise.

The 1970 JDM catalogue pictures of the gold cap variant of the 4520-8000 show it fitted with a brown crocodile strap but I’m afraid I cannot abide brown straps and so the strap I have selected is a modern Seiko crocodile-embossed black leather strap which I think sets it off beautifully.

For whatever reason, I have always had the impression that the 45GS had somehow lost some of the grandiosity of the 44GS.  That impression may have derived from its slimmer profile, suggesting something less substantial but I think the transition from dignified, majestic, low-beat 4420B to whipper-snapper, frenetic and modern 4520 added to an undermining of that weighty thing-of-beauty vibe of the original. 

However, having worked on this watch and with it now sat on my wrist, there is no doubt in my mind that this is a magnificent watch and a perfect sequel to the 44GS that both reflects the sign of the times yet respectfully evolves the original concept.