1990 MITSUBISHI ECLIPSE tow

/ii>--..AUTOMATIC TRANSAXLE
- Transaxle Control21-59
Sxxrolvalve175022E
6
LmeFrom
TooilFrompressure torque- pump 2;0%conver-
termntrd
valveDAMPER CLUTCH CONTROL VALVE AND DAMPER
CLUTCH CONTROL SOLENOID VALVE
Damper Clutch Control Valve
The damper clutch control valve is installed within the lower
valve body; it functions to regulate the hydraulic pressure
acting upon the damper clutch (incorporated within thetorqueconverter).
Damper Clutch Control Solenoid Valve
The damper clutch control solenoid valve is duty-controlled by
the signals from the transaxle control unit; this valve functions
to convert electric signals to hydraulic pressure.
Operation
(1) Because reducing pressure is applied to the
23rd line and
line
23a when the damper clutch is released, the sum of
the hydraulic pressure acting on the
# 1 land plus the spring
force overcomes the hydraulic pressure applied to the
#5land and
#6 land surface areas, thus causing the valve to
be moved toward the right.
When this happens, the hydraulic pressure from the
torqueconverter control valve enters from the 3rd line to
the 25th line, and hydraulic pressure is supplied between
the front cover of the torque-converter and the damper
clutch.As a result, the damper clutch is not activated, and
operation is the same as that of an ordinary torque-
converter.(2) When both throttle opening and vehicle speed reached the
damper clutch activation area, the damper clutch control
solenoid valve is duty-controlled by commands from the
transaxle control unit, thereby reducing the hydraulic
pressure applied to the
# 1 land left side.
As a result, the sum of the hydraulic pressure acting on the
# 1 land plus the spring force is overcome by the hydraulic
pressure applied to the
#5 land and #6 land surface areas,
thus causing the valve to be moved toward the left.
When this happens, the hydraulic pressure from the
torque-converter control valve passes through from the
3rdline to the
26th line, and through the oil cooler, and, at the
same time, the line pressure of the 1
st line passes through
the 27th line and enters the torque-converter from the 24th
line, thus causing hydraulic pressure to be applied between
the damper clutch and the turbine, with the result that the
damper clutch is pressed against the front cover, thus
activating the damper clutch.

21-60AUTOMATIC TRANSAXLE - Transaxle Control
REDUCING VALVE
Reducing valve
ExLine
press1
ExAdjusting
‘screw
N-R control valveunit
J&Pressure
+controlsblenoid valve.1750082
Line
’To pressure controlpressure solenoid valve
Line
’To pressure controlpressure
solenoid valve175ocs4The reducing valve is installed at the lower valve body; it
functions to produce a constant pressure which is
alwav2lower than the line pressure. With this pressure as
hydraulic pressure source, the control pressure is produced
LJYthe pressure control solenoid valve, thus activating the
pressure control valve.
l
(1
(2
) Line pressure is directed through the No. 1 port to the
space created between the
# 1 and #2 lands of the
reducing valve and is then directed to the above-mentioned
pressure control solenoid valve from the No.23 port as the
reducing pressure.
:) The pressure directed to the space between the # 1 and
#2 lands of the reducing valve is applied to the areaequivalent to the difference in area between the lands, and
constantly forces the valve toward the right against
thespring force. The reducing pressure is regulated in this
manner by the operation of the reducing valve.
(3) if the pressure between the lands becomes higher, the
reducing valve moves farther to the right against the spring
force and its
# 1 land closes the No. 1 port to shut off theline pressure while the
# 2 lands opens the exhaust poti !grelieve the fluid pressure. As a result, the reducing
press1is lowered.

AUTOMATIC TRANSAXLE - Transaxle Control
.-i:...
21-63To front clutch
Ex ExManual valve
To low/reverse brake
Pressure controlsolenoid valve
1750089
t ‘The hydraulic control system incorporates a “fail1
1safe feature” which prevents the gear shift from shift the selector lever from a forward drive range to
irthe reverse range while driving. This function is
:5activated when the vehicle is running at a speed of 7km/h (4.3 mph) or higher.
;If the selector lever is shifted into the “R” position.
*the transaxle control unit activates the pressure
:control solenoid valve to release the reducing
! ,-pressure. Once the reducing pressure drops, the.-a.rr./ -. jF! ;;1 ;I~N-R control valve is moved toward the right by the
spring force. This closes the No.9 port and causes
the pressure in passage 16 to be released. When
the pressure in passage 16 is released. the check
ball is forced against the right-hand port opening,
thus shutting off the line pressure. As a result, the
low-reverse brake is released. Although the front
clutch is engaged in this situation, the transaxle
cannot transmit the reverse driving power unless
the low-reverse brake is applied. Therefore, when
the transaxle is placed under the abovementioned
condition, it is the same as when it is in neutral.
c

AUTOMATIC TRANSAXLE - Transaxle Control21-73
‘elector Lever in “R”
Reducingvalve
ReducingTo low-reverse
OFF1750099
en the manual valve is shifted to the
“R” rangedirected to the low-reverse brake. Through this
ition, the pressure control solenoid valve func-pressure control, the shocks that would occur while
Ions under duty control from the transaxle controlshifting to reverse are minimized.
to reduce the reducing pressure in the No.23bOnce the low-reverse brake is engaged, the press-and to creaje another control. pressure in this
ure control solenoid valve is deenergized and normal
. The balance of forces established between thereducing pressure is reestablished in the No.23bntrol pressure and the force of the N-R controlline. Because this reestablished reducing pressure
Ivespring determines the degree that the No.9forces the N-R control valve toward the left, the line
e port will be open. The line pressure from thepressure passing through the No.9 port is applied
9 line is regulated by
passinq through the portdirectly to the low-reverse brake through the No. 16
ose opening has been adjusted and then isport and engages the brake with a strong pressure
force.

ir yAUTOMATIC TRANSAXLE
- Trahsaxle Control21-774th Gear
3rd GearRear clutchKickdown
1servo
release sideFront clutch
-
Rear clutch3rd1-2 shiftKickdown
Front clutch
q]b Ture,‘r z&eside
7
1750107
1Fromk-D3rd 14th pressure
control valve1 ;l;hiftpressure1750108
Upshift from
3rd to 4th Gear
.When the 4th pressure (line pressure) from the shift
control valve is directed to the rear clutch exhaust
valve through the No.8 line. the valve is pushed to
the right, closing the No.5c port. This cuts off the
pressure to the rear clutch and also releases the
pressure acting on the rear clutch through NO.
15port, No.20a port and No. 20
port.On the other hand, the rear clutch exhaust
valvewhich is pushed to the right opens the NO. 19
POnand directs the 4th pressure (line pressure) to the
right end of the
2-3/4-3 shift valve. The 3rdpressure (or the No.7 line pressure) is acting on theleft
end of the 2-3/4-3 shift valve. As this Pressure
..is equal to the No. 19 line pressure and acts on the
Mme area, the spring at the right end of the valveWhen the 4th pressure is released by the move-
ment of the shift control valve, the rear clutchDownshift from 4th to
3rd Gear
exhaust valve moves to the left, creating a
3rd gearstate, and the pressure is directed to the rear clutch.
At the same time as this happens, the 4th pressure
in No. 19 line which has been acting on the 2-3/4-3shift valve is released. This causes the
3rd pressure
established in the
No.7 line to push the 2-3/4-3shift valve to the right, and creates a 3rd gear state
where the line pressure from the
l-2 shift valve is
directed to the front clutch and the release side
chamber of kickdown servo cylinder through the
No. 12 line.shes the valve toward the
left. closing the No. 11me pressure port. This
btocks the pressure to the
front clutch and the release side chamber ofkickdown servo cylinder, and the pressure is re-
leased through the No. 12. and then the
No.9~ Pofi.

21-78AUTOMATIC TRANSAXLE - Transaxle Control
N-D CONTROL VALVE
.-.‘r
To rear clutch viarear clutch exhaust valve
N-Dcontrol
valve
EXpressure
Pressurecontrol
valve
t
Reducingpressure
t
Red”&pressure
175oz39
The purpose of this valve is to prevent shock from
occurring when shifting the select lever from “N” to
“D”. The valve supplies the rear clutch with the oilpressure regulated by the pressure control valve
only when the N-D shifting is being performed. After
the shifting is completed, the valve is switched over
to allow the line pressure to be supplied to the rear
clutch.
Selector Lever in ‘N”
When the manual valve is shifted to the “N” rangeposition, the line pressure from the oil pump is
directed to the N-D control valve through the No.4line. As the
#2 land has a slightly larger area to
which pressure is applied than that of the #3 land of
the N-D control valve, the movement of the valve
caused by the line pressure is toward the left, whichcloses the
No.5 port.

AUTOMATIC TRANSAXLE - Transaxle Control21-79
70 rear clutch via
rear clutch exhaustvalve
Frommanual valveOrifice
Line pressure From pressure
from manual
control valve
valve
175024
valveFrom manual
From pressure
valvecontrol valve175024Shift from “N” to
“D” .
When the manual valve is shifted from the “N” to the
“D”range position, the following sequence of events occur.
(1) The line pressure from the manual valve is distributed
through the No. 5 line to the NO. 5, NO. 5d and No. 5e lines ofthe N-D control
VdVe.
(2) The No.5 port is closed at this stage by the N-D control
valve.(3) There is a chamber with a check ball on the No.
5d line. Asthe check ball is held pressed against the downstream
opening of the chamber by the line pressure, the line
pressure passes through the
No.Se line, which has an
orifice provided.
(4 The line pressure, after being attenuated by the orifice, is
directed to the No.5c line.
(5) Meanwhile, the pressure from the pressure control valve
which has been regulated by the pressure control solenoid
valve is supplied through the No. 10 line.
(6) There is an orifice in the No. 10 line and the pressure which
is attenuated by passing through this orifice flows into the
No.
5c line.
(7) The No. 5c line pressure is directed to the rear clutch via therear clutch exhaust valve.
(8) If the rear clutch completes engagement, the duty setting
of the pressure control solenoid valve becomes zero
percent, increasing the pressure to the line pressure level.
(9) The line pressure thus established in the No.5c line works
on the N-D control valve to move it towards the right. This
rightward movement is’ caused by the difference in area to
which pressure is applied between the two lands.
(lO)The above movement of the N-D control valve opens theNo.5 port, and through the port, the line pressure estab-
lished in the No. 5 line flows into the No.
5c line and then is
directed to the rear clutch via the rear clutch exhaust valve.

AUTOMATIC TRANSAXLE - Transaxle Control21-81
3 CLUTCH VALVE
To front clutch
.To end clutch
To kickdown
servo release
Shift
control
solenoid
valve
- BShift control
solenoid valve
-A
II
J
ExIPlug
End clutch valve
‘11 E”
Line pressure
1750243End clutch valve controls the timing for supplying hydraulic
pressure to the end clutch.In 2nd Gear
(1) When hydraulic pressure is not being directed to the end
clutch valve, it is held pushed to the left by the spring force
(see above figure).
(2) If the
2nd pressure from the shift control valve is directed
to the end clutch valve via the No.6 line, the end clutch
valve is forced toward the right.
,nd Gear
Lrom manualvalveTo end,&tch.
2ndpressurepressure
I17501i