I live in Melbourne, Australia andhave had problems with my 406 with the gears very occasionally slipping and sometimes clunking severely on the downshift. The gears occassionally also get struck in any gear. I have taken to Peugeot dealers and Peugeot accredited auto transmission specialist however the problem still remains. After 100,000km the gearbox finally blewup. I replaced the gearbox with a secondhand one that had only done
30000km. I have exactly the same problems again. I have replaced the gearbox computer - no good The faults listed in the gearbox include, engine speed check, trottle potentiometer and engine torque signal. There are no faults listed in the engine computer. No one seems to know what the problem is.