peugeot 406 diesel year 2000 popping out of reverse?

if you been crunching it every time in reverse, the teeth on reverse gear could have gone. if it has been crunching every time, you also have clutch issues. if it has nt been crunching, an engine/gearbox mount that is loose or worn could make it jump out, as could a worn gear linkage.

me
June 2009