Reduction of Idling Rattle in Manual Transmission

In SAE paper SAE850979, 1985, the authors reported on a design technique for a clutch disc with nonlinear torsional characteristics for reducing transmission idling rattle. However, when design conditions do not allow sufficiently large first stage torsional angle or the transmission is loaded with large drag torque (such as when transmission oil is cold or the transmission has a power take-off unit), clutch discs designed using the previously reported technique do not necessarily give satisfactory result.

In this paper, the mechanisms generating idling rattle and their characteristics are further examined and a technique to reduce transmission idling rattle through elucidation of nonlinear torsional resonance is discussed.