An Analytical Study of Automotive Neutral Gear Rattle

A reduced order nonlinear model of an automotive manual transmission is presented and the neutral rattle case is analyzed. For a single frequency excitation and primary resonance, approximate analytical solutions are developed for a multi-degree-of-freedom model of a transmission using the method of harmonic balance. Based on these solutions, a simplified set of equations is developed for the study of neutral gear rattle and the use of these equations for design studies is illustrated. The nonlinear frequency response characteristics are discussed and the results are compared to similar studies described in the literature. It is shown that this analysis provides an improved understanding of the neutral gear rattle problem as well as an analytical basis for the nonlinear behavior reported in the literature.