SM02-025-0
Page 3
DESCRIPTION
The transmission and torque converter function to-
the drive shafts. The torque converter generates the
gether as an integral unit. The transmission is a six
hydraulics for the transmission functions. The gear-
ing in the transmission provides the different speeds
speed forward and three speed reverse transmission.
The transmission and torque converter transfers the
of operation.
power generated by the engine to the axles by way of
THEORY OF OPERATION
The transmission and torque converter function to-
impeller cover. This element is the pump portion of
gether and operate through a common hydraulic sys-
the hydraulic torque converter and is the primary
tem. Therefore, it is necessary to consider both units
component which starts the oil flowing to the other
in discussing operation.
components which results in torque multiplication.
This element can be compared to a centrifugal pump
With the engine running, the converter charging
in that it picks up fluid at its center and discharges at
pump draws oil from the transmission sump through
its outer diameter.
the removable oil suction screen and directs it
through the pressure regulating valve and oil filter.
The torque converter turbine is mounted opposite the
impeller and is connected to the output shaft of the
The pressure regulating valve maintains pressure to
torque converter. This element receives fluid at its
the transmission control for actuating the direction
outer diameter and discharges at its center. Fluid
and speed clutches. This requires a small portion of
directed by the impeller out into the particular design
the total volume of oil used in the system. The re-
of blading in the turbine and reaction member is the
maining volume of oil is directed through the torque
means by which the hydraulic torque converter m u l -
converter circuit to the oil cooler and returns to the
tiplies torque.
transmission for positive lubrication. This regulator
valve consists of a hardened valve spool operating in
The reaction member of the torque converter is lo-
a closely fitted bore. The valve spool is spring loaded
cated between and at the center of inner diameters of
to hold the valve in a closed position. When a specific
the impeller and turbine elements. Its function is to
pressure is achieved, the valve spool works against
take the fluid which is exhausting from the inner
the spring until a port is exposed along the side of the
portion of the turbine and change its direction to
bore. This sequence of events provides the proper
allow correct entry for recirculation into the impeller
system pressure.
element.
After entering the converter housing, the oil is di-
The torque converter will multiply engine torque to its
designed maximum multiplication ratio when the
rected through the reaction member support to the
output shaft is at zero rpm. Therefore, as the output
converter blade cavity and exits in the passage be-
tween the turbine shaft and reaction member sup-
shaft is decreasing in speed, the torque multiplica-
port. The oil then flows out of the converter to the oil
tion is increasing.
cooler. After leaving the cooler, the oil is directed to a
fitting on the transmission. Then, through a series of
The shift control valve assembly consists of a valve
body with selector valve spools. A detent ball and
tubes and passages, lubricates the transmission
spring in the selector spool provides one position for
each speed range. A detent ball and spring in the
the transmission sump.
direction spool provides three positions, one each for
forward, neutral, and reverse.
The torque converter consists basically of three ele-
ments and their related parts to multiply engine
torque. The engine power is transmitted from the
With the engine running and the directional control
lever in the neutral position, oil pressure from the
engine flywheel to the impeller element through the
