Abstract: A mobile dynamometer includes a slotted disk (12) and slotted disk (14) disposed on a rotating shaft (10) a predetermined distance apart. A slot (16) is formed in the periphery of the disk (12) and a slot (18) is formed in the periphery of the disk (14). A light source (20) and a light sensor (22) are mounted stationary with respect to the shaft and proximate the periphery of the disk (12). When the slot (16) passes proximate the source (20) and the sensor (22), a signal is generated. A light source (24) and a detector (26) are mounted proximate the periphery of the disk (14) such that passage of the slot (18) thereby generates a signal. The signal generated by the sensors (22) and (26) are two state signals. The time duration between the signals is measure and the angular deviation of the two disks (12) and (14) can be calculated therefrom. Measurement of this angular deviation determines the amount of twist on the shaft portion (28) between the two disks (12) and (14).

Abstract: An auxiliary transmission is provided for a light and medium duty truck having manual transmissions. The auxiliary transmission is an electrically actuated two speed gear system to be installed between the clutch and manual transmission for providing a direct pass through of engine rpm or for providing overdrive or underdrive depending on the gear set design.