Service: Rado Diastar – AS 1858

IMG_7932If it’s a Rado, it has to be Chris’s watch πŸ˜‰ He got this lovely Diastar from Japan, and it’s not ticking at all. A very unique design, with the faceted crystal and the oval case.

Let’s see what’s wrong…IMG_7934

On first sight, nothing much wrong here. Looks clean enough, and no visible damage.


The dial and hands have some damage, but are still in decent shape.IMG_7938

A lot of rust on the date change wheel, and on the date change spring.IMG_7940This isn’t too good, either. Time for a good clean!


The gear train.IMG_7955

All still in good shape.IMG_7956

Just the wheel bridge left.IMG_7958

The mainspring is still looking good, and continues to do so once it’s out of the barrel, so I will leave it.IMG_7960

Another view of the rust damage on the bottom plate.IMG_7961

The date set spring.IMG_7967

As you would expect, there is a fair amount of rust and dirt under the date change wheel.IMG_7968

The date ring got some damage as well, but that will clean up nicely.IMG_7969

Told you so πŸ˜‰IMG_7977

I clean up the rust with a fibreglass brush, and then soak the parts in citric acid, and then everything goes into the cleaning machine.IMG_7978

After the cleaning machine – looking good.IMG_7986

I start off with the balance jewels.


The clutch doesn’t sit on the cannon pinion, and it’s a bit loose, so I’m giving it a tiny squeeze under the microscope.IMG_7988

Barely wound, this is the first graph of the movement, and it’s looking good.IMG_7991

The bottom plate cleaned up nicely, too.IMG_7992

And the dial goes back on.IMG_7993

Hands in place.IMG_7994

Movement cased without the auto winder assembly.IMG_7996

The odd thing is that the auto winder only winds in one direction – I would have expected a bi-directional winder on such a high-spec movement.IMG_7997

A final adjustment.IMG_7998Very nice indeed!



16 thoughts on “Service: Rado Diastar – AS 1858

  1. Hi
    Looking for a Rado 1858 25J movement for my vintage captain cook MKII. Wondering if another AS 1858 say from the Diastar or MATTERHORN will fit into the watch?
    A novice here so let me know if you can help

  2. How does one find a caseback gasket for these? I am a self-watchmaker and recently have been acquiring these vintage DiaStars. I have one with this same movement, 17 jewels but the gasket is completely destroyed.

  3. Hi there,

    I am looking for a genuine Swiss factory original NEW/ NOS COMPLETE CROWN water proof with its rubber water seal for a RADO wristwatch. Here are 3 links below to watch showing the model back case cover and the crown in question, please let me know if you have one? And any other NEW parts you may have for this watch.


  4. Dear Christian,

    Just an inquiry. The back case mechanism looks clean and the rust is at the date change wheel & spring. How did the moisture entered into the case?

    Thank you.

  5. Hello
    i have a rado manhattan (as1859) and the clutch was hard on cannon pinion (exactly the same in you re picture ) so the crimping between the axis and the wheel is dead ,the wheel is rotating free on this axis …
    is there any way to crimp again the axis and the wheel ??

    thank’s and thank’s for these pictures and comments πŸ™‚


    The clutch doesn’t sit on the cannon pinion, and it’s a bit loose, so I’m giving it a tiny squeeze under the microscope.

    • Jean-Marc,

      Careful here – don’t tighten the cannon pinion, as the clutch isn’t located there! But I think you refer to the photo that shows the clutch, it’s just not the canon pinion. If you can’t tighten it, you need a new wheel I’m afraid…

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