Problem solved, I have unmount all the drive side, redo the assembly, lubricate with white lithium grease and everything seems ok now.

To whom may be interested :
- I remove the drive side bearing cone without the overpriced TL-8S11 shimano tool and without loosing the shift spring sub-assembly. The idea is to use "gravity" by hitting the axle on the bench with the drive unit bearing facing down. I have removed it like 10 times without loosing the shift spring assembly.
- To assemble the unit this way, the tricky part is to get the spring #9 to hook in the part #8. (following this CAD http://rideyourbike.com/shimano8axle...ructions.shtml)
www.youtube.com/watch?v=H7JqCCkhSUU
- The other overpriced tool TL-AF20 is useless to me. Everything is finding its right spot when tightening the cone with the bolt

Thanks to Dan Burkhart and Aaron for their online contribution for the maintenance of this IGH.