 The first way was in developing and promoting the Tracta joint (designed by his friend Pierre Fenaille), which was, until manufacturing techniques had progressed sufficiently to allow the successful manufacture of the constant velocity joints commonly in use today, the preferred choice of most manufactures of vehicles that had driven front wheels.Tracta joints were used by many of the pioneers of front-wheel drive, including DKW between 1929 and 1936 and Adler from 1932 to 1939 as well as the cars designed by J A Grégoire that will be mentioned later.The Tracta joint was fitted to most of the military vehicles that had driven front wheels used by most of the combatants in the Second World War.