A GR 280 with 3 axles, they proposed York or Serma ( in Bourg en Bresse) third axle , lifting or not.
Such a conversion needed reinforcing the chassis, and was certainly more expensive that a true 6x2. Didn’t Berliet have the GRH 280, the “H” at the end meaning it’s a 3-axle truck?
A same lorry was used in UK :
DEANB:
Berliet 1979.0
That’s a fine looking motor even though its French
robthedog:
DEANB:
Berliet 1979.0
That’s a fine looking motor even though its French
“…even though it’s French”. That reminds me the narrow-mindness of most of my compatriots whe the subject of British trucks is raised! 
TLM 10M2 Onatra Marseille.
A very typical articulated of the early sixties, as I used to see them whem I was a kid!
Not only road tractors but also in harsh tipper work, a GLM 10M2 6x4:
Once more, a very typical and interesting picture of the sixties! I think the M2 was the firts serie of Berliet trucks fitted with hydraulic power steering. The “M” (1950-61) had an air operated, assistance manufactured by Jourdain-Monneret, if I’m right.
Froggy55:
Once more, a very typical and interesting picture of the sixties! I think the M2 was the firts serie of Berliet trucks fitted with hydraulic power steering. The “M” (1950-61) had an air operated, assistance manufactured by Jourdain-Monneret, if I’m right.
Surprising that it had power steering, Froggy, given the size of that steering wheel.
I thought it would be a case of blip the throttle at the same time as tugging one side of the wheel
in a tight slow turn situation. 
Berliet started fitting air-operated power steering standard on the heavy models (19 tonnes and more) in 1950 with the GLM 10. Only the smaller GLC (12 tonnes) and GLR (16 tonnes) had to wait the M2 version in 1961 to get an hydraulic steering. More surprising, Renault’s heavy range (15 tonnes and over) had air-operated power steering from 1934. Just think trucks like the standard Mack B61 6x4 were basicly offered with elbow-grease steering as late as 1966… I even think that some British 8-wheelers or long-distance tractors had it optional in the late sixties too.
Froggy55:
Berliet started fitting air-operated power steering standard on the heavy models (19 tonnes and more) in 1950 with the GLM 10. Only the smaller GLC (12 tonnes) and GLR (16 tonnes) had to wait the M2 version in 1961 to get an hydraulic steering. More surprising, Renault’s heavy range (15 tonnes and over) had air-operated power steering from 1934. Just think trucks like the standard Mack B61 6x4 were basicly offered with elbow-grease steering as late as 1966… I even think that some British 8-wheelers or long-distance tractors had it optional in the late sixties too.
My B61 Mack in Australia in the 60s certainly didn’t have power steering,
so I don’t have to just think about it. 
Also, although I am not sure of the truck or time,
but it was much later than that that I first encountered power steering
on anything at all British built. 
Spardo:
Froggy55:
Once more, a very typical and interesting picture of the sixties! I think the M2 was the firts serie of Berliet trucks fitted with hydraulic power steering. The “M” (1950-61) had an air operated, assistance manufactured by Jourdain-Monneret, if I’m right.Surprising that it had power steering, Froggy, given the size of that steering wheel.
I thought it would be a case of blip the throttle at the same time as tugging one side of the wheel
in a tight slow turn situation.
I don’t know about French regulations but German regs said that trucks had to have large steering wheels incase of power steering failure which was why Mercs and MAN were fitted with large wheels. I don’t know when that ‘law’ was instigated though.
Pete.