22—TOROUE-FLITE TRANSMISSION
CHRYSLER SERVICE MANUAL
of the kickdown piston. The force of the pres-
sure on the "off" area, assisted by the kickdown
piston spring, is sufficient to overcome the
forces of line pressure and throttle compensa-
tor pressure acting on the apply side of the
kickdown piston.
Application of the kickdown piston when
shifting from breakaway to second is softened
by the accumulator.
d. Low-Reverse Servo
The low-reverse servo has two functions which
are performed independently. The low-reverse
servo piston is moved hydraulically to apply
the low-reverse band through the low-reverse
band lever, strut, and anchor. The results are:
(1) To hold the carrier of the front plane-
tary gear set stationary while the rear clutch
(applied) drives the sun gear. This provides a
reverse ratio of 2.20 to 1 through the front
planetary gear set, as shown in Figure 3.
(2) To hold the carrier of the front plane-
tary gear set stationary while the front clutch
(applied) drives the intermediate shaft and
kickdown annulus. This provides the 1 (low)
range operation at a ratio of 2.45 to 1 through
both planetary gear sets (see Fig. 7) which
may be used for engine braking. Initial en-
gagement of the low-reverse servo (when shift-
ing from neutral to low or reverse) is softened
by compression of the low-reverse servo cushion
spring.
The servo piston is released by a return
spring when the source of apply pressure is
discontinued.
e. Accumulator
An accumulator cushions the front clutch en-
gagement when a forward drive button is push-
ed in, and the application of the kickdown band
in the upshift from breakaway to second. It is
connected in parallel and to the passage which
supplies line pressure to the apply side of the
kickdown servo.
In neutral and reverse the accumulator pis-
ton is held released by the accumulator spring,
there being no pressure applied to the piston
at these times.
In the D (drive) range, for the automatic
upshift from breakaway to second, the accumu-
lator piston is again moved by line pressure
(kickdown servo apply) acting on the large end
of the piston. The force of line pressure (as-
sisted by the accumulator spring) is sufficient
to overcome the force of line pressure (front
clutch) which is acting on the small area of the
accumulator piston. This action cushions the
application of the kickdown band.
7.
PRESSURE REGULATING VALVES
a. Regulator Valve
The regulator valve controls line pressure at
a value of approximately 90 psi. for all oper-
ating conditions except reverse. Line pressure,
which is supplied by the front pump (at car
speeds under 35 mph.) is routed directly to a
primary reaction area in the regulator valve
body. For all conditions except reverse, line
pressure is also routed through the front valve
body to the secondary reaction area. A line
pressure of 90 psi. (acting on the two reaction
areas) is sufficient to overcome the force of the
regulator valve spring and move the valve to
the position that will allow oil to flow through
a restricting hole in the regulator valve body
to the torque converter.
If the oil flow from the front pump exceeds
the amount necessary to feed the torque con-
verter and transmission line, pressure will rise
slightly, causing the regulator valve to move to
a new position where excess oil from the front
pump pressure port is allowed to dump into
the front pump suction port.
Above a car speed of approximately 35 mph.,
the rear pump furnishes the oil needed by the
torque converter and transmission at a line
pressure of approximately 90 psi. When this
condition is reached, the pressure increases
slightly and the regulator valve moves over to
a new position where the excess flow is dumped
from the line pressure port into the front pump
suction port. Under this condition the front
pump check valve closes and all of the oil
pumped from the front pump is dumped back
through the large valve opening into the front
pump suction port. Thus the front pump turns
with reduced effort since it is operating at a
low pressure.
For reverse operation, oil must be at a pres-
sure of 225 psi. This is accomplished by shut-
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