The MK8 drive gear was a little bit tricky to install. The pulley from FLUX is to big so that the filament didn't get enough into the drive gear and so it didn't have enough grip. So luckily we have a 3D Printer, conclusion: Print a new pulley that fits!
After the new pulley was also inserted I ran some fantastic prints! Without clicking, with tube on the filament roll and filter/oiler. But caution, it is may to early for a conclusion on that.
I will post images tomorrow evening, if you were interested.