Zenith 400

[bertieng]

Just downloaded from DRSD site:

"The modification more important brought by Rolex on the caliber Zenith is the lowering of alternations per hour of the pendulum of 28 800 to 36 000 as well as an oscillation frequency that passes of 5 to 4 Hz. This in order bring this movement chronograph to the standards of Rolex.

The movement Zenith with its 36 000 alt/h renders impossible for fluid lubrications. The El Primero needs a lubrication to dry to bases bisulfure of molibd

[slickdick]

Serviceing an cal 400 is no issue. The bold text above does not apply on the cal 400 though. If you bought a movado or zenith donor, you can service them through movado or zinith, no problem.

I've got mine serviced before i put it in my daytona. I still kept the donor watch, so if i need another service in a couple of years, i transplant the movement back to its donor, and sent it to service again.

[bertieng]

"The bold text above does not apply on the cal 400 though."

Why? I believe Rolex modified from Zenith 400 into their 4030, right?

So servicing will be a problem if there is no donor but just bought the movement.

Do you also have to put back all the date function parts onto the donor before sending it back to Zenith? Quite tedious and troublesome, isn't it?

[slickdick]

The whole rolex story applies only to rolex modded zenith movements. If you have such movement you will have to find a watch smith willing and capable of working on the movement, you cant send it off to rolex.

Yes, i have to put the date parts back, what can i say, the whole frankenway is tedious and troublesome. However no pain no gain.