Application Considerations with the Cummins Sundstrand DMT-25 Hydromechanical Transmission

A fully automatic hydromechanical transmission has been successfully applied in a variety of heavy duty trucks and is now being offered by numerous truck manufacturers. Significant differences in application and installation technique exist between a hydromechanical transmission and fixed ratio truck transmissions. This paper discusses major application and installation considerations with the hydromechanical transmission and also suggests new approaches for engine/transmission package optimization, governor control interface improvements, and increased vehicle productivity.