Pobeda 2602 Full Overhaul — Strip-Down of a 1955 Soviet Caliber

Overhauling the Pobeda 2602 — A Full Strip-Down of a 1955 Soviet Fifteen-Jewel Caliber

"A movement that has served more than seventy years and still keeps these numbers is already a small miracle. The rest is just understanding why it wore where it did."
— Igor, watchmaker

This is a complete service of a Pobeda on the 2602 caliber, built in 1955 at the Second Moscow Watch Factory. Unlike a focused look at a single sub-assembly, the goal here is the whole machine: strip it down to the last screw, clean it, lubricate it correctly, and put it back together so that a watch of more than seventy years runs as it was meant to. The example chosen was deliberately one of the rougher ones — worn, repeatedly opened over the decades, and visibly tired. That makes it the most honest teacher.

Pobeda wristwatch before disassembly, dial side, with a worn cream dial and a small seconds register at six. — The patient before work begins, dial side. The cream dial is heavily aged, the gilt worn from the case, and the small seconds sit in their sub-register at six o'clock.

The same Pobeda seen from the caseback side before opening. — The same watch viewed from the back, the case still closed.

The crystal together with its bezel ring lifted from the case. — The crystal is removed together with its bezel ring.

The hands being pulled from the dial. — The hands are drawn off next.

The removed hands laid carefully into the cell of a parts tray. — ...and laid carefully into a cell of the parts tray, where they cannot be lost or bent.

The caseback opened to reveal the movement. — The caseback is opened.

Movement in the case with a red arrow on the stem-retaining screw and green arrows on the case-mounting screws. — The red arrow marks the screw that retains the winding stem; the green arrows mark the two screws holding the movement in the case. The stem screw is loosened about one to one-and-a-half turns and the stem withdrawn, after which the case screws come out and the caliber lifts free toward the crystal side.

The winding stem withdrawn from the movement, lying beside it. — The winding stem is out of the movement.

The Movement in the Open

Free of its case, the caliber shows itself in full, including the Côtes de Genève striping across the bridges — finishing that the camera struggles to do justice. The architecture here is the classic Pobeda layout: a screwed balance with a fixed balance stud, no shock protection, a regulator index but no fine beat-error adjuster. It is plain, it is honest, and as we will see at the end, its simplicity comes at a price.

The movement removed from the case, showing Geneva stripes and the Pobeda engraving, with the case ring beside it. — The movement out at last, in all the glory of its Geneva waves. The plate is engraved Pobeda, Ч-55, fifteen jewels, with the serial number around the rim.

The Balance and Its Breguet Hairspring

The first thing off is the balance, lifted together with its cock. This is a screwed balance running against a fixed stud, with no shock protection at all. There is a regulator index, but no fine beat regulator. One detail deserves a pause: look at the single turn of the hairspring that rides higher than the rest. That is a Breguet overcoil, named for its inventor, shaped so that the period of the balance-and-spring system is independent of amplitude. The technology migrated to wristwatches from pocket watches. Its one drawback is that it adds height, which is why thin calibers avoid it — but where thickness is not critical, the overcoil earns its keep. The balance is set aside in a Petri dish under glass to keep dust off; we will return to it later, in depth.

The balance removed and set aside, with a green arrow pointing to the raised Breguet overcoil of the hairspring. — The balance removed. The green arrow indicates the Breguet overcoil — the turn of the hairspring lifted above the flat body of the spiral.

The pallet fork and escape wheel visible on the plate with the balance removed. — With the balance gone, the pallet fork and escape wheel are exposed.

Taking Down the Motor

Now the motor. The ratchet wheel, the barrel bridge and the barrel come off, the sliding cam clutch is extracted, and the barrel is opened. Note how the barrel click spring is made in this caliber: the stiff R-shaped spring is what gives these watches their slightly harsh winding feel. Later production replaced it with a soft, thin spring. This particular sub-assembly is left intact — refitting that spring afterwards is more trouble than it is worth, and it will wash perfectly well together with its bridge.

The winding mechanism disassembled, showing the Pobeda-engraved ratchet wheel, sliding clutch parts and barrel bridge. — The winding mechanism apart. Note the R-shaped click spring of the barrel — the source of the stiff winding action that later versions softened.

The barrel bridge removed from the movement. — The barrel bridge is off.

The sliding-cam clutch components and the barrel laid out together. — The parts of the sliding cam clutch, with the barrel.

Pallet Fork and Going Train

The pallet fork and the going train come next, and there is nothing unusual here — the bridges lift off and the wheels come out in turn. What remains is the center wheel, and to free it the minute pinion must first be drawn off its arbor, which means crossing over to the slow side, under the dial.

The pallet bridge and pallet fork removed and laid on the bench. — The pallet bridge and fork. No surprises in this department.

The train bridge and the going-train wheels removed. — The train bridge and the wheels of the going train.

The center wheel still in place on the plate before crossing to the dial side. — Only the center wheel is left. To lift it, the minute pinion must come off first — so the work moves to the slow side, beneath the dial.

Under the Dial: the Slow Side

At last we reach the dial. The screws on the edge of the mainplate are loosened, the dial comes away, and the slow side is dismantled. Here sit the motion work, the balance cap jewel, the hour wheel with its spring washer — which must not be forgotten on reassembly — and the keyless works.

The edge screws on the mainplate that secure the dial. — The dial-retaining screws sit in the edge of the mainplate.

The dial removed and set aside, exposing the slow side of the mainplate with the keyless works. — Dial off, the slow side revealed. The aged dial rests to the left while the motion and keyless work remain on the plate.

Close-up of the balance cap jewel set into the mainplate. — A close look at the balance cap jewel on the plate side.

The balance cap jewel being removed from the mainplate. — The cap jewel is removed.

The hour wheel lifted off together with its spring washer. — The hour wheel comes off with its spring washer — a part that absolutely must be put back on reassembly.

The minute pinion and center wheel removed. — The minute pinion and the center wheel are taken out.

The keyless works opened up on the slow side. — The keyless works is opened and dismantled.

The individual components of the keyless works laid out. — The parts of the keyless works.

The fully stripped movement, all parts removed from the mainplate. — Disassembly complete. Everything goes to the bath for washing and cleaning.

Reassembly and Lubrication

Cleaning done, the rebuild begins — this time with MTs-N oil. The going train goes first, and in a set order: escape wheel and intermediate wheel, then seconds wheel and center wheel, all carefully aligned and capped with the bridge. Then the barrel is assembled, a couple of drops of oil go onto the mainspring coils and the arbor, the lid is closed, and the barrel drops into its seat on the plate before the bridge goes over the motor. The depthing of the wheels checks out cleanly.

The going-train wheels reinstalled on the mainplate. — The train wheels back in place, aligned and ready for the bridge.

The train bridge fitted over the reinstalled wheels. — ...and capped with the train bridge.

The barrel reassembled with its lid. — The barrel is reassembled — a touch of oil on the mainspring coils and arbor, then the lid is closed.

The barrel set into its seat in the movement. — ...and seated in the movement.

The barrel bridge fitted over the barrel. — The barrel bridge goes back over the motor.

The movement with a red arrow indicating the seconds-wheel arbor that carries the seconds hand. — The red arrow points to the seconds-wheel arbor that carries the seconds hand.

Cap Jewel, Slow Side and Escapement

Crossing back to the slow side, the balance cap jewel is oiled first — a drop on the cap jewel itself, never the through-jewel, sized to cover about sixty to seventy percent of the stone. The jewel is seated and secured with its screw. The minute pinion goes back, the keyless works is reassembled, lubricated and closed under its cover. Then back to the motor: the crown wheel and the ratchet wheel are refitted, and finally the pallet fork returns with its bridge. The pivots of the pallet fork are left dry — remember what excess oil there did to the watches in earlier work.

A droplet of oil being applied to the balance cap jewel. — Oiling the balance cap jewel — the droplet should cover roughly two-thirds of the stone, no more.

The oiled cap jewel being set onto the mainplate. — ...and the jewel set back onto the plate.

The slow side and keyless works being reassembled on the mainplate. — The slow side and the keyless works go back together.

The cover plate of the keyless works being closed. — The keyless cover is closed over its parts.

Close-up of the escape wheel and the pallet jewel. — A close look at the escape wheel and the pallet jewel.

The pallet fork and its bridge installed on the movement. — The pallet fork and its bridge are in. The pivots of the fork arbor are deliberately left unoiled.

The Tricky Part: Servicing the Balance

Now the most interesting work — cleaning and lubricating the balance. The catch is that the cap jewel on the balance cock can only be oiled by fully taking the balance assembly apart, because the screws sit underneath rather than on top. The balance is laid wheel-up and the cock pressed down with pegwood; the balance-stud screw is loosened by no more than a single turn. Back the screw out completely and you buy yourself a great deal of grief — refitting it without a special holding screwdriver is possible but genuinely hard. The balance is then tipped so it hangs free, the stud is nudged out of its slot, and the parts separate. The balance goes to be washed; the cock is set so the slots of its cap jewel are visible, and those tiny screws — each the size of a poppy seed — are removed. Wash and dry the cock and cap jewel, oil the cap jewel to that same sixty-to-seventy-percent coverage, align the screw holes, and drive the screws home. Patience, attention, and care, in that order.

Why all this fuss over the balance? Look closely at the pivots of the train wheels: the arbor steps down to the pivot abruptly, forming a shoulder. That shoulder is what keeps the oil from running down the pivot onto the arbor and the pinion. Overfill it and the oil creeps onto the pinion, the wheels damp and effectively glue themselves, and the watch runs stiff. For the oil to stay put it must be of the right viscosity and within the prescribed amount; sometimes the surfaces are epilamed to limit spreading. The balance staff, by contrast, tapers smoothly into its pivot, conically, with no shoulder. Over-oil the balance or break the technique and the oil, with nothing to hold it, runs onto the balance wheel, then onto the hairspring, and the coils stick together. Hence the old line: you cannot spoil porridge with butter, but you can certainly spoil a watch.

With the balance reassembled, it goes back in: the stud drops into its slot and the hairspring is led under the regulator pins in one motion, the stud pushed home with fine pegwood and locked with its screw — but the balance pivot is not yet in its jewel, it sits to one side. The balance is then suspended on tweezers and lowered into the movement so the pivots enter their jewels just once. If for any reason the balance must come out again, the jewels have to be washed and re-oiled — otherwise there will simply be no oil where it is needed. That is the price paid for a simple design: pull the head out and the tail gets stuck. But it runs beautifully. The timing machine shows a small beat-error discrepancy, well within tolerance.

The balance assembly with a red label pointing to the balance-stud screw. — The balance, focused on the balance-stud screw — loosened a single turn, never fully out.

The balance wheel with its hairspring separated from the cock. — The balance wheel and hairspring lifted away.

The balance cock being disassembled to reach the cap jewel. — The balance cock taken apart to expose the cap jewel and its poppy-seed screws.

A droplet of oil placed on the balance cap jewel at the correct size. — The cap jewel oiled — the droplet sized exactly as shown.

The balance cock being reassembled. — The balance cock reassembled.

The balance wheel reinstalled into the cock. — The balance wheel reinstalled.

The Result, and What the Caliber Teaches

So, what came of it? Four seconds of loss per day, on a thoroughly worn and venerable movement of advanced age — and that despite the state it arrived in. A mechanism that has worked for more than seventy years and held figures like these is, in itself, remarkable.

Timing-machine app reading about 17999 beats per hour against an 18000 target with a four-second beat error. — The verdict on the timing app: 17,999 against a target of 18,000 bph, a beat error of about four seconds, roughly minus four seconds a day.

But look hard at the design. Fifteen jewels means the center wheel is not jeweled — and that is the most heavily loaded wheel in the movement, working directly against the mainspring. The result is wear in the bushings of the bridge and the plate; the wheel begins to wobble, the rate goes crooked, and once the wear is bad enough the wheel can jam outright and stop the watch. There is an old joke about a watch that is two jewels short — and it was born from exactly this. Add those two jewels and the movement would barely wear at all.

There is no shock protection on the balance, either. That was simply the era. Provided the watch is not abused or dropped on concrete it is fine — but there is one quiet failure mode: the balance has a little vertical freedom, so the pivot hammers against the cap jewel and slowly peens into a mushroom shape. The mushroom grows, the rate drifts, positional error rises, and eventually the balance jams. Worse, removing such a balance is a real problem, because the peened pivot will not pull back through the through-jewel. When that happened, the balance was replaced together with the cock — which is exactly why so few authentic movements survive today.

The keyless works has its own childhood ailment: over time the stem tunnel in the plate wears and widens, the stem sags, and the setting lever begins to slip when the stem is pulled to the setting position. The cure is tempering and re-bending the setting lever. And then there is the wear in the barrel seats — two more jewels that are not there — which lets the barrel cant and chew into the plate and bridge, a well-known problem and not only on the 2602. The caliber is also sensitive to which seconds hand is fitted: a hand without a counterweight produces a visible waver in the trace, a wave-like rate, so final regulation, like the depthing check, should be done with the hands in place.

All of this was eventually addressed. In time there appeared an essentially equivalent caliber, the 2603, corrected and supplemented, with enough jewels and with shock protection — but that was already a Raketa, the one that was so highly valued. That, however, is a different conversation.