POWER TRAIN
-
Automatic Transaxle
Valve
Body Assembly
Retainer
Q-
-
Valves removed
Valves installed
9x-439
The
F4ACl
has a relatively simple, cast aluminum
valve body that uses only five valves. No governor
pressure or throttle pressure is used to operate
this valve body. These two pressures have been
replaced by electronic signals from the output speed
sensor and throttle position sensor. Shift valves have
and to direct fluid to the clutches, torque converter,
lubrication system, and the solenoid/valves by
means of the manual and switch valves.
One side of the rooster comb (secured to top of
valve body) operates two switches, the park neutral
also been eliminated and replaced by the solenoid/
and transmission range switches. The solenoid and
ii
valves in the solenoid assembly.
pressure switch assembly is indirectly connected
The valve body has two major functions. To control
to the valve body through an extension of the case
line pressure and torque converter clutch pressure
in the oil pan area.
Solenoid and
pressure switch
assembly
Screen
filter
Solenoid and Pressure Switch Assembly
The solenoid and pressure switch assembly is controlled by
the TCM through the transmission control relay. The assembly
consists of four solenoid/valve assemblies that control hydraulic
pressure to four of the five clutches in the transaxle and the
torque converter clutch. A unique feature of the solenoid/valves
are that they directly control the application of a clutch. In
other electronically controlled
transaxles/transmissions,
the
clutches are indirectly controlled by the solenoids through the
normal hydraulic valving. The solenoid assembly also contains
three pressure switches that feed information to the TCM. The
“UR” pressure switch, the “2-4” pressure switch and the
“OD”
pressure switch. The eight-way electrical connector to the sole-
noid is sealed and bolted in place with the bolt tightened to
proper specification.
The assembly is located outside the transaxle case, under
a sound shield and protective cover, towards the front of the
vehicle. The filter screen between the solenoid assembly and
valve body protects the assembly from contamination and is
a replaceable item. However, if the valve body and solenoid
‘a
pack have been heavily contaminated, the solenoid pack should
be closely inspected to determine the need for its replacement.
The solenoid pack is not a serviceable unit.
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