  We discuss the conservation of angular momentum in nuclear time-dependent
Hartree-Fock calculations for a numerical representation of wave functions and
potentials on a three-dimensional cartesian grid. Free rotation of a deformed
nucleus performs extremely well even for relatively coarse spatial grids. Heavy
ion collisions produce a highly excited compound system associated with
substantial nucleon emission. These emitted nucleons reach the bounds of the
numerical box which leads to a decrease of angular momentum. We discuss
strategies to distinguish the physically justified loss from numerical
artifacts.
