We consider the relaxation to equilibrium of a spatially uniform Maxwellian gas, We expand the solution of the nonlinear Boltzmann equation in a truncated series of orthogonal functions. We integrate numerically the equation for nonisotropic initial conditions. For certain simple conditions we find interesting proximity effects and other transient relaxation phenomena at thermal energies. Furthermore, we define a resummation of the orthogonal expansion which is more convenient than the original o,e for the numerical analysis of the relaxation process.