Ollech & Wajs 2002 Valjoux 7730 – Service

Under the loupe today is a very nice vintage Ollech & Wajs 2002 Valjoux 7730. O&W was created in Switzerland in the late 1950’s, and grew in popularity in the 1960’s, especially with servicemen, sportsman, divers and aviators thanks to a strong reputation for quality and dependable mechanical watches. O&W still operate today, see their website Valjoux 7730 Service


OW 2002 service



The watch arrived in running condition, but was not keeping time and had not been serviced in many years so was in need of a full service and a replacement of the crystal .





Upon opening the case the Valjoux 7730 movement is revealed.


Dial and hands in good original condition.Ollech Wajs Chronograph service


Starting with the service of the Valjoux 7730 movement.


The chronograph parts are now disassembled.


The movement is now fully stripped down, ready for cleaning.Valjoux 7730 Chronograph service


Assembly can commence after cleaning and inspection of the parts.



A new mainspring is fitted into the barrel.




Barrel and train wheels are in place.


Train and barrel bridges fitted.


The movement is running well, so the assembly of the chronograph layer can commence.


Now turning my attention to the case and cosmetic aspect of the work. The crown gasket is completely perished, it is disintegrating in the crown, affecting its operation.




New crown gasket is definitely in order.




The pushers are also disassembled for replacement of the gaskets.  Pushers can get sticky over time causing them to not operate properly. This is caused by contaminants, gasket perishing and lubrication drying out.



A new crystal is fitted to the case. It is an acrylic crystal with tension ring.






Work on the movement and the case is now complete, and the watch is fitted with a new caseback gasket.


The Ollech & Wajs 2002 Valjoux 7730 is looking great after a sympathetic restoration and full service. I would like to conclude this article by thanking my client Nick for entrusting me with his watch.

Valjoux 7730 Service