A re-threshing system for a combine harvester is provided. The system comprises a re-thresher housing (81, 82) which bounds a passage, a re-thresher auger having flighting elements (77) mounted on a shaft (73) arranged for rotation within the passage. The re-thresher housing includes one of a first and second interchangeable cover (82, 92), wherein said first cover (82) is employed in a re-threshing mode and comprises a plurality of guide vanes (84) mounted on the inside thereof and having a profile which substantially conforms to the cylindrical swept volume of the flighting. In the re-threshing mode crop material is conveyed through the passage by interaction between the guide vanes and flighting of the auger in rotation. The second cover (92) is employed in a non re-threshing mode and comprises an inner wall surface that substantially conforms to the swept volume of the flighting elements, in the non re-threshing mode crop material is conveyed through the passage by interaction between the inner wall surface and flighting of the auger in rotation. The system further comprises removable threshing fingers (80) mounted on the shaft between the flighting when in the re-threshing mode.Linvention porte sur un système de re-battage pour une moissonneuse-batteuse. Le système comprend un boîtier de re-batteuse (81, 82) qui délimite un passage, une vis sans fin de re-batteuse ayant des éléments volants (77) montés sur un arbre (73) conçu pour une rotation à lintérieur du passage. Le boîtier de re-batteuse comprend lun parmi un premier et un second capots interchangeables (82, 92), ledit premier capot (82) étant employé dans un mode de re-battage et comprenant une pluralité daubes de guidage (84) montées sur lintérieur de celui-ci et ayant un profil qui se conforme sensiblement au volume balayé cylindrique des éléments de vol. Dans le mode de re-battage, un matériau de culture est transporté à travers le passage par interaction entre les aubes de guidage et vol de la vis sa
