During calibre disassembly, special attention is given to extracting the automatic group, as the mainspring must first be fully discharged. The movement of the automatic group is placed in a metal basket divided into compartments to be put in the machine for pre-wash. A mechanical arm dips the basket from time to time in four glass tanks, the first tank contains a cleaning solution and three very refined benzines and the other three tanks are for rinsing. The machine then performs the complete drying of the parts. This takes about fifteen minutes. After the pre-wash we move on to the total dismantling of the movement, during which the watchmaker verifies all the components in order to check consumption, especially of those parts that are subject to a lack of lubricant (such as the bearings), or particular wear (such as the axes of the wheels). Continuing the disassembly, we move to the mainspring which is removed from the barrel, balance spring, bridge anchor, and so on. The technician checks the state of each component, especially the pivots of wheels which in our Rolex are in place and prepares the movement for the second wash.
In particular, the spiral, which must be flat and concentric, and the rotor bushing (within which the axis rotates), which must be aligned with the automatic bridge, are checked. Since in our case the latter is put back in place, we proceed with the operation by using special tools provided by the House and our trusty hammer. The technician must also check the 24-hour bridge before checking the dial train. In our case, due to wear, it was necessary to change the minute wheel. Once all the necessary repairs and replacements were done, we proceed to the second washing of the movement (this time completely disassembled), which occurs in another machine similar to the previous one, but with a different washing programme.
The parts, in fact, are housed in a metal bin, divided into compartments and put together according to material (brass with brass, stainless steel with stainless steel…) to avoid damaging them in case they bump against each other. The smaller pieces, such as screws, are placed into finer mesh baskets.