Seiko Lord Marvel 5740-1990 from June 1964: A de-tuned Grand Seiko?

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Prior to the introduction of the first Grand Seiko in 1960, the pinnacle of the Seiko product tree was occupied by the Lord Marvel, introduced in 1958 as a luxurious refinement of the Marvel series introduced two years earlier. 

Adapted from the 1960 Japanese market Seiko catalogue. Original scan credit to Anthony Cable of Plus9time.com

The first Lord Marvel movement used as its basis the 11.5 ligne (25.6 mm) Marvel but with significant upgrades in jeweling, finish and features.  The gear train was fully jewelled in the new 23 jewel Lord Marvel (with the exception of the barrel) with the third wheel, escape wheel and pallet fork benefiting from end-piece cap jewels (the pre-cursor to Diafix) on the dial side and the third, escape and sweep seconds wheel similarly capped on the train side.

The 23J Lord Marvel movement (photo credit : http://www.grand-seiko.com)

The fixed stud holder of the Marvel was replaced by moveable and the overall level of finishing at higher level, marking the Lord Marvel out as a top tier product (world standard according to Seiko’s marketing blurb at the time).  The early watches were available in steel, capped gold and 18K solid gold cases, the latter selling for an astonishing 26,000 Yen in 1960 (for reference, the first Grand Seiko was priced at 25,000 Yen in 1963).

This first generation of Lord Marvel underwent a number of refinements in its 6-year lifetime but its position as the king of the hill had been usurped after only two years by the Grand Seiko, whose movement was a development of the larger 12½” (27.6 mm) Seiko Crown. 

The 21 jewel Seiko Crown 560 calibre that formed the basis of the Grand Seiko 3180 (see here for more information)

That first Grand Seiko movement, the 3180, was in a sense the result of a merging of the refinements of the Lord Marvel movement with the performance benefits offered by the larger Crown calibre.  The Grand Seiko inherited the moveable stud holder from the Lord Marvel, added a stop-seconds facility as well as tadpole lever micro-adjustment regulation to the balance bridge.  It also increased the jewel count by two through jeweling to the barrel floor and lid but, curiously, not to the upper barrel arbor hole.   

The Grand Seiko 3180 movement (photo credit : http://www.grand-seiko.com)

In 1961, the Crown itself benefited from some of these developments through its evolution into the Crown Special with the addition of a stop-seconds lever and moveable stud, a Diafix setting for the centre seconds wheel but retaining steel bearings throughout for the barrel.

The 23 jewel Seiko Crown Special 341 calibre. Adapted from a photograph sourced from vintagewatchhunter.com

In 1964, the first-generation Lord Marvel was replaced with an upsized second generation, this one powered by the 5740A 23 jewel movement running at 18000 bph.  The 5740A is, to all intents and purposes, a slightly detuned 3180 (or a tuned-up Crown Special).  At its base is the 27.6mm Crown (the 560) but it inherits the higher-level finishing and moveable stud of the smaller 23 jewel Lord Marvel movement, but also the stop seconds facility and tadpole lever micro-adjustment from the 3180.  The two-jewel difference between 3180 and 5740A is accounted for by the end-piece cap jewel serving the pallet fork on the 3180 (of questionable value given that the pallet fork is commonly left unlubricated) and a Diafix cap jewel serving the sweep seconds wheel.  There is also a small difference in the jeweling of the barrels:  both benefit from two jewels, but in the 3180 both jewels are in the barrel itself (lid and floor) whereas in the 5740A, one jewel is in the barrel lid and the other in the barrel bridge.  But I am getting a little ahead of myself, although would observe that I have not overshot.  In pausing at this point, you may have deduced, that this is not an account of the first-generation Lord Marvel, but of the second.

The watch we have before us is a very early example of the second-generation Lord Marvel, a gold cap 5740-1990 from June 1964.  I bought this watch in September 2017 and here we are, three and a half years later, finally getting around to giving it some attention.

Externally, the watch is in excellent condition.  The dial is immaculate barring a small beauty spot just shy of the 5 marker and the case carries only the sheen of a patina born of gentle wear against clothing.  Access to the movement is achieved by prising off the snap-on case back with a casing knife.  A helpful cut-out is located between the lugs at the 12 o’clock position (we note that the case back has been rotated 180 degrees from what might be regarded as conventional).

The inside of the caseback bears the model number, the AGF marker, signifying that this is a gold-filled (or gold cap) case and, interestingly, the Daini crane motif, signifying that the case, at least, was made in the Daini factory in Tokyo rather than the Suwa factory in Nagano.  We must remember that the Marvel – Lord Marvel – Crown – Crown Special – Grand Seiko 3180 family tree is a product of the Suwa division, not Daini.  This is not the first time that I’ve seen the Daini crane imprint on gold-capped Suwa division watches (see here for example).

The movement looks rather magnificent, enhanced even by the gentle tarnishing that comes with the considerable time that must have passed since its last service.

The serial number on the train bridge suggest that the movement may date from October 1964, about 4 months later than the date of the case.  This does rather support the hypothesis that the cases and movements were manufactured on separate sites and then assembled at one or other of the two.  The case appears to be gold cap on a brass substrate rather than steel, as evidenced by the copper salts visible around the outer circumference of the movement aperture, the result of galvanic corrosion of the brass in contact with the more noble metal, gold.  It is also worth noting the presence of the stop-seconds lever, visible between the barrel and train wheel bridges.  You will see that it acts upon the sweep seconds wheel.

A timing measurement on a full wind reveals reasonable amplitude (260 degrees), adequate beat error (0.4 ms) but some significant positional variation (+2 sec/day dial up, -20 sec/day dial down).  Nothing to put the wind up me at this stage but I’ll ask you to remember the positional variation for later on.

The case construction is old school dress watch.  Having removed the case back, the movement is not removed by dropping it out from the rear, but from the top, having removed first the bezel and crystal and the two case screws securing the movement to the mid-case.  So first up, prise off the bezel and captive crystal, again aided by a helpful cut-out positioned at nine o’clock.

Then, remove the two case screws.

And finally, the movement is free from the case and laid, for the moment, in the protective embrace of the inverted bezel and crystal.

The dial really is a peach and the hands characterised by a lovely concave taper along each outer edge.  Aligning the hour and minute hands with the seconds hand aids removal.

Removing the dial requires the two dial feet screws to be loosened.

And we can at this point, ease the dial away from the movement.

A number of features catch the eye.  As with the train side, the third wheel and escape wheel both benefit from Diafix settings;  the lower barrel arbor bearing is steel; and the quality of finishing of a standard in keeping with the elevated status of the Lord Marvel model range, notwithstanding its recent demotion at the hands of Grand Seiko.

Dismantling can commence, starting with the Diashock settings, lower and upper.

In retrospect, I would note that the upper pivot of the balance arbor is sitting a little low in the Diashock frame but I did not notice this at the time.  With the balance removed, we also note the presence of a divot near the balance bridge locating dowels, placed there by a previous watchmaker to adjust the balance endshake.  Again, I had not taken this in at the time of disassembling the movement.

You will also see that I have detached the two Diafix springs in preparation to remove the two cap jewels.  Note the jewelled barrel arbor bearing on the barrel bridge and the very attractive gold-coloured barrel, making a striking contrast with the rest of the movement but complementing the golden engraved script on the train bridge and the Diafix surrounds and springs.  This is a beautiful movement.

With both barrel and train bridges removed, we can take a closer look at the stop-seconds (or hacking) lever, sitting atop is film spring.

The base of the barrel makes do without any jewelled bushing, instead relying on the jewelled bearing mounted in the barrel bridge, but the lid bushing is jewelled.

Removing the lid exposes a perfect-looking and relatively clean mainspring, unsullied by the lashings of molybdenum grease used to lubricate Seiko automatic mainsprings.

And uncoiled, the spring looks fit and healthy and eminently reusable.

A pause for breath.

With all parts spick and span, my choice, as usual, having selected reverse, is whether to begin with the rehousing of the mainspring or the fiddly business of refitting and oiling four Diafix cap jewels.  I opt for the latter.

This operation proceeds easily and without notable incident.  I am at the point now where Diafix settings have become routine, in fact rather enjoyable.  No longer a task to be dreaded.  The mainspring provides just a little more than the routine in that the diameter of the barrel is neither fish nor fowl when it comes to selecting the correct drum and handle from my small selection of mainspring winders. 

The shaft on the Bergeon number 8 handle is too large though for the hole in the centre of the mainspring and so I end up pairing the Bergeon drum with a handle from my set of vintage winders.

In the photo above the mainspring has been wound into the drum and I am in the process of carefully extracting the handle.  You should be able to make out the nub of the hook on the shaft whose job it is to locate into the hole in the end of the mainspring, allowing purchase as it is wound into the drum.  The drum is just a little too large for the barrel and so pressing home the mainspring is precision affair if the operation is not to be met with disaster.  It is not.

The scene is now set for reassembly, starting with the setting parts, the centre wheel and its bridge and then the cannon pinion and minute wheel.

In go the barrel, escape wheel, third wheel and sweep seconds wheel along with the hacking lever and its spring film washer.

Then the two bridges, the barrel bridge first and then the train wheel bridge, the latter proving a bit of a fiddle.

You may notice that the crown wheel has a bit of a brown hue to it – the result of tarnishing to the plating and the ratchet wheel is similarly affected.  Wanting as perfect a looking movement as possible, I managed to locate some very clean understudies from my Crown/Marvel parts bin and following a clean, chose to fit these as replacements for the originals.

You will notice that I have also fitted (and oiled) the pallet fork and its bridge.  One of the pallet jewels was chipped at its upper most edge but as this is not a functional part of the jewel I chose to stick with this fork in the absence of any better alternatives (I have a few but most of those had wear to the faces of the jewels or were otherwise compromised, including one, infuriating (again) purchased as a new part from a part supplies house. 

This point in proceedings usually marks the beginning of the end of the process – lower Diashock oiled and fitted, in with the balance, topped off with its Diashock.

However, instead, what followed was a fraught week of trouble-shooting, adjustment, frustration, and hair pulling.  The sequence of events is a little difficult to unpick now, having emerged from the process, but started with the balance refusing to sit true prior to me fitting the Diashock setting.  Usually, the movement will start to run before the shock setting is refitted.  I noticed that the hairspring was out of flat and so removed the balance wheel from the bridge and then the hairspring from the wheel and then spent three days correcting the kinks that were kicking it out of flat and then re-adjusting the terminal curve so that it passed cleanly between the regulator curb pin and boot over the full range of adjustment.  It is not entirely clear to me whether the distortions to the hairspring were present prior to cleaning or whether inflicted either as a result of the cleaning process in my centrifugal cleaning machine or from my attempts to refit the balance when it plainly did not want to be refitted.  I was so consumed by this task that I abandoned any attempts to document it but with some dogged determination to work through the process, I found myself with a correctly adjusted hairspring.  Sometimes, these trials can undermine confidence, but in my experience, if you embrace the challenge, you may find yourself having acquired a previously elusive new skill. 

However, I was not yet out of my sticky predicament.  The movement was now running but with huge positional variation and a very noisy timing curve with the dial side upwards.  In undertaking this iterative round of removal, adjustment, refitting, I had noticed two things:  firstly, that there was very little resistance to adjustment of the regulator lever and secondly, that there was a considerable end-shake to the balance.   It was this latter problem that was causing the noisy timing curve with the dial side facing upwards.  With the dial side up, the free vertical movement of the balance wheel within the range offered by the endshake was bringing the plane of the wheel closer to the balance bridge with the result that the bottom of the regulator boot was touching the balance spoke as it rotated.  It became clear to me that this degree of freedom of movement was the result of the upper pivot of the balance arbor not properly locating into the Diashock frame and this is what was causing the timing inconsistencies.  This realisation brought to mind the divot that I had seen on the mainplate when disassembling the movement.

As I observed earlier, this mark will have been made by a watchmaker to lift the balance bridge upwards at its base, thereby moving the bearing supporting the balance arbor downwards towards the mainplate – in other words, an attempt to reduce the endshake.  The question was, why was the endshake so bad and why was I seeing it so much more obviously now, rather than before?  I would observe that prior to starting the service, the watch was displaying significant positional variation which suggests that the endshake was there from the start, if not quite as bad as I was seeing now.  I turned my attention at this point to the Diashock frame.  For whatever reason, the balance arbor pivot was not correctly locating and so I wondered whether there might be something amiss with the frame itself.  So I removed the balance once more from its bridge and noticed that the bottom surface of the frame was sitting just shy of level with he bottom of the hole in the bridge.  And it was at this point that a little light bulb went off in my head and I wondered whether the Diashock frame itself was correct.  According to my watch parts catalogue, the Diashock upper frame for the 5740A has part number 014223 – a part shared by all of the Crown based movements.  I located a spare Crown movement and removed the frame from its balance to compare with the one fitted to my watch.  This is the result.

The frame on the right is the one taken from my watch; the one on the left from one of my spare Crown 560 movements.  I double-checked another Crown part with the same result.  Clearly, the frame from my 5740A is incorrect.  It is too shallow and when fitted will not sit low enough in the bridge to properly locate around the balance arbor pivot.  The fault lies squarely with a previous watchmaker who had fitted an incorrect part at service.  I wonder if it was the same watchmaker who then tried to adjust endshake by whacking a divot into the mainplate? 

Salvation is clearly at hand.  I cleaned the correct salvaged part and set about refitting to the balance bridge.  Here is the cleaned frame ready to locate into the hole.

Lining things up.

And time to tap it home.

One final refitting of the balance to the bridge and the whole assembly to the movement and the watch is up and running sweetly, with no tippy tapping audible from across the room when the movement is oriented dial side upwards!

Some final adjustment to the height of the stud, and I am seeing excellent amplitude, negligible beat error and minor positional variation.  Phew!

I can see the light at the end of the tunnel now and so move on to fit the hour wheel and its film washer as the last step before refitting the dial.

The dial and hands go on without a hitch.

And we can then reunite the movement and case by setting the movement into the case from the top.

This next step requires a decision about whether to refit the crystal and bezel first, before the case screws or the other way round.  In the end I strike a middle path and set the crystal to protect the dial and hands before fitting the two case screws and then remove it again to free up the movement while adjusting the alignment with the stem.

The caseback gasket is a reasonably beefy o-ring that sets into a groove in the back of the mid-case.

The crown gasket was rock hard and would have provided no meaningful protection against water ingress and so I spend a couple of hours digging it out from behind the captive retaining washer and then working in a replacement, aided by lashings of silicone grease.  My choice of o-ring is probably not ideal, but it will provide considerably better protection than simply to have reused the original crown with its original gasket.

And so we find ourselves at the conclusion to this rather more challenging project than I had anticipated at the outset.

That challenge derived not from any inherent technical complexity of this movement, nor from unanticipated compromises in operation wrought by the passage of time and the abuses inflicted upon the watch by its former owners, but instead was a consequence of sloppy maintenance by a past watchmaker.  I am not a professional watchmaker – just an amateur hobbyist – and I have no illusions about the gulf that exists between what I can do and what a properly trained and skilled watchmaker can do.  But as with any vocational profession, results will depend on the standards of the individual and just as we might beware of railway arch mechanics tinkering with our cars, so we must take care in our choice of technician to work on our watches.

Setting aside the journey though, the result is really rather special.  I drew comparisons in the preamble between the Lord Marvel and the Grand Seiko and in surveying the result of this particular project, the similarities between the two appear much closer than the differences.  And it is perhaps really in the details that those differences really resolve.  The Grand Seiko really was a luxury product but the Lord Marvel remains a deserving runner up of the period in terms of perceived quality and delivery.  That is, until you factor in the aspirations of the Daini division and the creation of their own standard setter.  But that’s another story.