Rolex Movement Removal - Prima / Extra Prima / Ultra Prima (pre-War, 20s, 30s)

I find there are a few guides on how to strip-down modern Rolex watches like Submariner and Oyster models, but none for the early pre-war Prima models of the 1920s and 30s. So, having part serviced one lately, I decided to write one up.

This applies to most pre-Oyster models, like Prima, Extra Prima and Ultra Prima, as well as other Rolex models that feature this duel-split case design.

The case back is split from the bracelet using a watch-case opening knife or similar slim blade. Be careful when doing this. The case back can be rotated to help loosen it or to create a larger gap to get the tool in.

Unlike more modern Rolex watches, there is no press-release 'clutch' mechanism. Instead the crown is held by a small screw next to where the stem enters the movement. To remove the crown, turn the screw in very small increments while applying pressure to the crown. If the screw is unwound too far, it will come free of the lever that holds the crown and a complete disassembly is required to painstakingly refit it, so be careful to turn the screw in super fine increments until the crown and stem pop out of the case.

Two screws hold the movement to the casing from the back. These are located opposite from one another at the edges of the movement, pictured. Looking at the movement with the crown to the right, the long screw is located at the top and the shorter screw is opposite at the bottom. The movement is now free and can be rotated in the casing, but can not be removed from here.

You will notice a lip on one side of the front bezel. This is where the front case should be split from the bracelet, again using a watch-case opening knife or similar. The front bezel and glass should now drop out along with the movement, which can now be lifted out.

** On certain models, the movement may need to be rotated to a specific position for the movement to be removed, though this is more common where the movement is removed from the rear.