Clean and Assemble the Knobs and Gears

gear train

Cleaning the Synchron gear train

Unfortunately the gear train plates are riveted and cannot be separated.  So the mechanism needs to be cleaned while assembled.  I use a small ultrasonic cleaner.  Watch repair people use many different cleaning chemicals, wash several times and rinse.  There are even cleaning solutions which contain cleaner and oil, leaving the mechanism lubricated.  I used Alconox.  Without an ultrasonic cleaner, I have used carburetor cleaner and an array of small brushes.  I oil the pivots with 0 wt Mobil One and apply the oil with an oiling pin.  A tooth pick will work just as well.

Cleaning and assembling the knobs and arbors

These are listed in the order needed to install them.  You will notice the gears need to be disassembled in a specific order.

The white Nylon washers are the bearing that hold the arbor in place.  The arbor is generally hollow with a threaded insert.  The insert can be adjusted so that the spring washer maintains a light but sufficient pressure on the clutch.  The black discs are clutches that encourage both gears to turn together.

Often the set or grub screws will dimple the pinion, making it difficult to remove a knob or gear.  These dimples need to be filed smooth before reassembly.

Blue Knob

blue knob exploded

The blue knob has two gears which are encouraged to turn together by the spring washer.  The spring washer is the third from the left and it will be held in the correct position on the arbor.  I prefer to place the flattest part against the metal gear.  The screw tightens until it reaches the interior insert.  Adjust the tension on the spring washer by adjusting the position of the interior insert and then tighten the screw until it contacts the insert.

blue knob assembled

Gold Knob

gold knob exploded

The gold knob and arbor are similar to the blue in function.

gold knob assembled

Blue Platter

The large blue gear is actually the background for the 12 hour clock dial.  It requires a long allen wrench to loosen and tighten the grub screw.  It is actually attached to the hour post on the Synchron clock works.  This gear must be assembled before the white knob.

blue flywheel

White Knob

white knob exploded

The white knob arbor has a small gear press fit onto the arbor.  It is difficult to disassemble and should be left along if working properly.  The small gear can be removed with a puller if needed. 

white knob assembled

Grey and Red Knobs

grey and red knobs exploded

These two knobs are concentric and so the assembly is a bit unusual.  The spring washer is on the knob side and basically bulls the outside gear to compress the center gear against the inside gear. Note the two clutches. 

The engineering was poorly done on my example as the grey knob does not fit the arbor correctly.  The two metal washers on the right hold the grey knob in place while the dual grub screws pinch the arbor.

When setting be sure and hold two knobs at the same time and the center gear will turn with one or the other and therefore be adjusted by which ever knob has the most friction on the clutch.

grey and red partially assembled grey and red knobs assembled