Chronograph pusher problem.

[Len33]

Morning, all!

One of the pushers on my chronograph is in need of replacement, but I am unable remove it.

Unlike some watches, there are no clips on the inside and no screwdriver slot.

I tried gripping the pusher with a pin vice, whilst holding the tube with pliers  and attempting to unscrew the pusher, but no luck with that.

Under a microscope, I can see no evidence of a thread holding the tube in place.

Can somebody tell me if some of these pusher assemblies are a 'press fit?'

Any suggestions would be very welcome.

Thanks.

 

 

[KOwatch]

For a screw-in shaft, the shaft would have a screwdriver slot in it, and would be screwed/unscrewed from the inside, then the pusher cap lifts off the pusher body/sleeve on the outside. The body/sleeve can  screwed in using spline tool, or pressed in. At any rate, because of these splines, the pusher cap would not turn from the outside to unscrew the shaft

It would be odd that the shafts had no screw slot, but the often require shortening to fit the movement, and in your sitation it almost looks like they were filed down after they were installed in the case.