CR10 S - Dual Z Synchronizer

On my CR10 S; some desync of dual Z axis on initialization of the machine.
you will need :

2 x pulley GT 2 40T W6 B8
1 x pulley GT2 20T 5x6 with teeth
2 x pully GT2 20T 5x6 without teeth
3 x M5 screw for the axes of the pulley with nuts
1x M5 screx for the axe of the button
1 x 852mm GT2 - 6mm - 2mm ((https://www.amazon.fr/gp/product/B07D8ZZD9Y/ref=ppx_yo_dt_b_asin_title_o02__o00_s00?ie=UTF8&psc=1)

You will loose 2 or 3 cm on completed height of printing