Seiko 6139 chronograph

Seiko's museum calls the 6139 the world's first automatic chronograph, launched in the spring of 1969. That is a contested claim — Zenith announced the El Primero in January 1969 and the Heuer, Breitling and Hamilton Chronomatic in March — but the sequence of dates is in Seiko's favour: movement production began in October 1968 and Japanese sales in May 1969, while the others were still announcing prototypes. The engineering is the part that holds up regardless. Toshihiko Ohki designed a vertical clutch because there was no room for a horizontal one, and it was the first in any chronograph. He combined it with a column wheel, which is otherwise a high-end feature, and Seiko sold the result as a 5 Sports Speed-Timer — a mass-market sports watch, through department stores and base exchanges, not a luxury piece. The Skylab story, which is told loosely everywhere, survives checking better than most. Colonel William Pogue put a Seiko on layaway at an Army and Air Force exchange on 10 June 1972 and paid it off three days later for $71. He wore it aboard Skylab 4, which ran from November 1973 to February 1974. The watch was auctioned in October 2008 with its original layaway receipt, the instruction booklet, a NASA photograph of Pogue wearing it aboard the station, and a two-page handwritten letter from him explaining its history. That is unusually good provenance for this kind of story. One correction worth making, because the trade gets it wrong constantly: the watch Pogue actually owned was a yellow-dialled 6139-6005. In ordinary usage "Pogue" has spread to cover any yellow-dial 6139-600x, and dealers routinely list a 6002 as a Pogue. If somebody calls a 6002 "the Pogue", they are using a nickname, not describing the watch. One functional quirk to know before you wear one: there is no running seconds hand. The central sweep hand is the chronograph only, so you cannot tell at a glance whether the watch is going.

Wearing. It is about 40 to 41 millimetres with a 46 millimetre lug-to-lug, which is modern-feeling, and it was built as a tool rather than a treasure. Owning a genuinely significant movement without paying Swiss prices for one. A column wheel and a vertical clutch in a watch that was sold through a PX is a strange and good thing. Where it falls short, and these matter more than usual on this watch: No hand winding and no hacking, and no running seconds hand at all. Accuracy around fifteen seconds a day and amplitude of roughly 180 to 220 degrees are normal for the design, not defects. The 70 metre rating is history. The pushers are plain push pushers, not screw-down, sealed by one small gasket each. And the decisive one: Seiko's own US service centre lists the 6139 among calibres it will no longer service, because parts have been discontinued for years and there is no stock. Every repair now depends on donor movements. Buy a working chronograph — the premium over a non-working example is almost always less than the cost and risk of making a non-working one work.

This one test separates a cheap problem from an expensive one. If the sweep hand lands on the same wrong spot every time, the hand is simply not fitted at zero, or the reset hammer needs adjusting — both cheap. If it lands somewhere different each time, there is wear in the chronograph works, and that is expensive.

It should start instantly and cleanly with no stutter or jump, run smoothly, and stop dead. A hand that lags on starting, runs erratically, or loses time against the watch is a slipping clutch.

The thirty-minute register should advance crisply once per revolution.

They should move a short, defined distance with a crisp click and spring back fully. Sticky, gritty, mushy, or a pusher that stays in, means gaskets or springs at minimum.

This is the strongest single authentication tool on this watch. The dial markings date it: WATER 70m PROOF from 1969 to mid-1970, WATER 70m RESIST from mid-1970 to late 1972, and no water marking after that. A dial code that does not fit the wording — a 6030R code paired with PROOF text, for instance — is a red flag, because Seiko had dropped PROOF by then.

Genuine Suwa dials have a subtle, almost imperceptible sunburst. Aftermarket dials often show deep concentric ridges.

The inner rotating ring is UV-sensitive plastic that fades from vibrant yellow to near white over decades. A perfectly vivid yellow ring in an otherwise fifty-year-old watch is a replacement, not a survivor. A white ring is normal ageing, not a fault — though counterfeiters have painted rings white to fake exactly that. A black inner bezel is correct on Thong-Sa imported South-East Asian and Australian 6002s.

Ask for a photograph of the movement and look for a bright arced track on the bridges under the rotor. That is rotor wear and it is difficult to correct.

Check the dial edges and the inside of the crystal for staining, and the sub-dial for corrosion. The T-type dials in particular corrode around the minute sub-dial where the lacquer is thin. Water inside a 6139 attacks the dial, and 6139 dials are effectively irreplaceable.

Assume it has not, unless somebody shows you a date. A mechanical watch of this age that has not been opened in a decade is not broken, but it is running on oil that has dried into something closer to a paste, and every hour it runs that way wears the pivots. Seiko's own guidance is a service roughly every three years. For a watch of this age that is actually worn, three is the careful figure and five is the realistic one. A service means the movement stripped, cleaned, lubricated and regulated, new gaskets, and a pressure test. And the rating on the dial is history, not a promise. Everything sealing a watch like this is rubber, all of it is as old as the watch, and rubber hardens and shrinks. Whatever it says on the dial, treat it as not water resistant until somebody has fitted new gaskets and pressure-tested it, and ask for the date of that test.

The single most common complaint, and it has three distinct causes in ascending order of seriousness. The hand is simply not fitted at the exact zero point, typically after an impact or a careless refit. Or the reset hammer's eccentric adjustment is out, which a watchmaker corrects. Or there is wear and poor lubrication in the chronograph works. The diagnostic is in the checks above: same wrong spot every time means the first two, different spot each time means the third. All three need the watch opened, so all three are watchmaker work — but the first two are cheap and the third is not. One trap specific to this movement: the chronograph seconds shaft has a profiled, non-round cross-section so the hand cannot slip during reset, and the orientation differs between individual movements. A hand transplanted with a movement often will not sit at zero. This is why replaced chronograph hands are common on 6139s.

A clutch ring engages the fourth wheel to the centre seconds pinion; two coupling levers lift it away when the chronograph is stopped and let it drop when you press start. What fails is slippage from worn or dirty surfaces, and it is described as prone to failure without regular servicing. The fix is strip and clean, and replacement from a donor if the surfaces are worn. Watchmaker only.

Seiko's magic lever winds in both rotor directions using two arms that grab the wheel next to the ratchet wheel. The pawls wear and the watch stops winding efficiently; the lever itself is a cheap part when the right one can be found. The more serious version is rotor and bridge wear, which leaves a bright curved scar that is difficult to correct. Test it by wearing the watch a full day, then leaving it off overnight: it should still be running in the morning and comfortably past twenty-four hours.

A typical wear point. The steel arbor slowly wears the softer brass, turning round holes oval, until the barrel contacts the mainplate or the centre wheel. The repair is either punching the barrel to close the play or replacing it from a donor. You cannot see this as a buyer. It is why a service history and a watchmaker's inspection matter more on a 6139 than on almost any other affordable vintage watch.

It is what gives the pushers their feel. Mushy, inconsistent or notchy pusher action, or a chronograph that starts when it should stop, points at the column wheel, its jumper spring or the operating levers — though dirt and dried oil produce identical symptoms and are far more common. Strip and clean first; replace from a donor only if genuinely worn.

Every 6138 and 6139 pusher uses the same D-profile gasket. Old ones deteriorate and stop protecting anything, and the most frequent problem on these watches is sticking pushers and crown, from broken springs or perished gaskets. Bad servicing makes it worse — one documented case had three gaskets stuffed in where one belongs. These are plain push pushers, not screw-down, sealed by that one small gasket. Operating a pusher pushes its stem inward and drags the seal across the tube, which on a fifty-five-year-old gasket is an open invitation. Never operate the chronograph wet, and treat the 70 metre rating as historical only. Use good pushers when they are replaced, not the cheapest reproductions — the common modern ones have no bevelled top, inadequate gasket grooves and disproportionately thick tips.

Seiko's US service centre will not service the 6139: parts have been discontinued for many years, there is no stock, and they ask customers not to send them. Every repair depends on donor movements and aftermarket parts. Worse, the 6139A and 6139B chronograph parts are not interchangeable, which halves the donor pool for any given watch. And one fault is effectively terminal — chronograph wheel damage is extremely expensive to repair or simply impossible.

The 6139-600x is among the most heavily counterfeited vintage watches. See the checks above for the dial code, the sub-dial finish and the inner bezel. Two dial makers age differently: T dials, prevalent to about 1975, fade from yellow toward translucent and corrode around the minute sub-dial; R dials, from 1972, keep a darker yellow. A dial whose ageing does not match its type is suspect. As with the Turtle, there is no fix, only honest description.