Cursor joystick out on csl elite ps4

Tibor Fuchsel

Hi, the cursor joystick on my csl elite ps4 wheel got dislocated with the black rubber washer/ o ring dropping out of the wheel. The cursor is still usable but you can't select anything on the right direction with it at the moment. Any advice on how I can insert the rubber washer back in its place? Not to sure where to take the wheel apart etc? Many thanks for any advice on this.