Control method and apparatus for shifting means for axle coupling and differential locking

The method involves deriving vehicle speed from wheel speeds, determining slip limit speeds for various shift/lock elements, eliminating systematic noise effects and computing slip or actual slip speed per shift/locking element, comparing with the limit speed per element, selecting the decisive slip speed or speeds for enabling a lock, filtering out noise effects and generating a shift demand when a limit is reached. An independent claim is also included for the following: (a) an arrangement for automatically controlling shift elements for connection of drive axles and locking differentials.