Duriez gearbox

The l'Epicard Duriez gearbox, as it's officially called, was first constructed in 1948. It's based on a normal Traction Avant gearbox housing but with some modifications made. All other gearbox components are different from the normal Citroën parts. Externally the gearbox can be identified by the lever for reverse on the front of the gearbox. The gearbox was available in 3 versions based on the 9x31 crownwheel and pignon set. With the 8x31 Citroën mountain crownwheel and pignon set 3 more gearbox configurations could be made for mountain terrain.

The Duriez gearboxes were fitted to the Deutsch Bonnet racing cars in 1948 and this combination won some races.

Here are some figures of this gearbox:

The 4 speed conversions as mentioned above are now nearly unobtainable. However, there is an alternative. The 4 speed gearbox from a D series can be used. Another interesting option is using the D series gearbox and engine.

Which parts?

Not all D series gearboxes (and engines) can be fitted into the Traction Avant. The engine and gearbox as fitted to the pre September 1965 DS (and ID break) and the pre September 1966 ID Berline can be fitted to the Traction Avant 11 (UK Fifteen). The later engine and gearboxes will only fit in a 6 cylinder (here a 5 speed is also possible!).

Problems

Gearchange
On the Traction there is a lever for 1st-reverse and a lever for 2nd-3rd. On the D there is a lever for left-right and a lever for up-down. So it's clear the Traction gearchange has to be modified to operate the D gearbox. This is done by letting the gearlever move one of the original traction rods when moving up-down. The left-right movement of the gearlever has to be translated into the operation of another rod or a cable. Another option is using the D gearlever mechanism.

Driveshafts
Contrary to popular believe the Traction driveshafts are great. Our 85bhp DS powered 4 speed gearbox 11BL ran over 20.000 km on original (rebuilt) Traction driveshafts. No these driveshafts don't make the car act like a kangaroo when cornering (unless they are worn or not fitted properly!). Even the sharpest hair pin bends could be taken with high speed and full power. They never gave any trouble and were still like new when the car was sold.

Gearbox
Mating the Traction driveshafts to the D gearbox is another problem. The traction 4 bolt claws for taking the driveshafts are used. On the gearbox an (aluminium) plate is fitted to cover the big hole left by the D hubs. In this plate a seal is fitted with the correct internal diameter for the Traction driveshaft hub.

Bellhousing

Specialists

If you don't want to do the conversion yourself, there are a number of specialists who can do the job for you.

• Roger Williams, UK.
  Offers the 4 speed gerabox conversion as a kit.
• Peter Larson, Sweden.
  Can do both the 4 speed gearbox conversion and both engine and gearbox conversion. He also has experience with these conversions. Both Normale and Legere cars.
• Philippe Chauvet.
  Offers a kit for fitting the D series gearbox into a Traction. Doubtfull if this will fit into a Legere.
• Jose Fransen, Belgium.
  Offers a kit for fitting the D series gearbox into a Traction. Doubtfull if this will fit into a Legere.
• Willem Bakker, Netherlands.
  Does the 4 speed conversion. No info available.