Service Manual

Table Of Contents
627333-A 3-3
Transmission and Solenoids
TRANSMISSION AND SOLENOIDS
THEORY OF OPERATION
The transmission is a 16-speed forward and 3-speed
reverse powershift transmission with electronically
controlled hydraulic power assisted shifting. A TCU
(Transmission Control Unit) sends 12 volt power to
electric coils on the front of the transmission to change
gear ratios. There are a total of nine clutches, which
engage in different combinations of two determining the
speed of the output shaft.
The transmission is coupled to the engine through a
rubber damper to absorb some of the shock between
the engine, the transmission and the propschaft.
The electronic control allows the TCU to monitor
various functions such as throttle position, input speed,
output speed, temperature and thus control shifting as
well as display error codes.
A charge pump mounted at the left top of the
transmission provides the hydraulic flow for the
transmission. There is an auxiliary output drive on the
back of the charge pump that can be used to drive
various hydraulic pumps for the various systems
mounted to the chassis. There is a second auxiliary
drive on the top right side of the transmission for
systems requiring another hydraulic pump.