OMEGA Seamaster Chronograph Cal.321 Overhaul

Omega: Seamaster Chronograph: Cal.321

Symptoms: Overhaul

Repair contents: Overhaul, spring and gasket replacement, case and bracelet cleaning

Repair cost: 38,500 yen (reference price)

It has been disassembled.

The Seamaster Chronograph is equipped with the Cal. 321 movement, which was used by NASA for the moon landing and has also been reissued in recent years.

Assemble

Cal.321 is the predecessor of Cal.861, and has a strong vintage feel. 861 is simpler, or rather, more streamlined. 321 uses pillar wheels, but 861 has been changed to cam type, and there are some small changes.

Beat Error Adjustment

In this year's movement, the balance ball is directly moved to adjust the beat error, but in the 861 this has been modified to make adjustment easier.

The back side was also assembled.

The back side is not much different from 861. There is no rust and it is in good condition.

Zodiac foot correction

The rod that connects the dial and the movement is called the zodiac foot, but some of it has worn down over the years. If it is worn down, it cannot be firmly attached, and both the dial and the movement will become loose, so we will reinforce it with a special adhesive-like substance.

Attach the dial

Attach the needle

The hands of a chronograph may become loose when inserted and removed. The tubular part of the hands (the hakama) may also crack over time. This can sometimes be fixed with adjustment, but sometimes the hakama is custom made to order. This particular watch will be adjusted to see how it goes.

Assembly complete, casing

We will now carry out a running test. This is a very popular chronograph movement. The repair period will take 4 to 5 weeks.

We will continue to introduce repair details and upcoming models. Please check back again if you are interested.