[Solved] Gearbox zf 6as800 optitronic renault - problem change 1 - N - R

Hello,
by reading the other topics, I understood that there were people here looking for the fault before replacing everything! It's nice!

My problem :
when I maneuver my truck (renault midlum with zf 6as800 optitronic gearbox) the 1st shift - reverse gear R: sometimes it works well sometimes I am stuck in both 1, R or N ... only the engine stop + 5 seconds and restart allows me to start again.


This hot or cold. Before the problem arises, often 1 and R pass abruptly. No problem on the road: 1 2 3 4 5 6 - even when I stop it goes back to 1.


The clutch, the clutch fork are new; I changed the electronic box ... the purges and calibrations are done ...
All ecu up to date ...
Do you have any idea and / or experience of this phenomenon? What exactly is the air supply for? because I read that this command is essentially hydraulic.
The gearbox at 544000km without intervention (it is a truck that only traveled the road, very little delivery so little maneuver)

thank you so much
cordially
Clement

Post a photo of the nameplate because something does not suit me with this model name.

Hello,
thank you for your reply.
It is a gearbox of the type : ZF ECOLITE 6AS-800
with Renault electronic module.

I just tested what a technician recommends on this forum: bleed the clutch by lifting the rear wheels
It seems to work better; but if that's it the French mechanics are really bad: more than 3 days of immobilization, an electronic control changed and the gearbox declared dead

However if you have an idea I am interested. It is the same box as volvo daf and man; with Renault software

Thank you in advance.
cordially

Hello, the problem came from an input error in the tacho.