Chrysler Town & Country/Voyager, Dodge Caravan, Plymouth Voyager. Manual — part 72
Be sure to examine the fluid on the dipstick closely. If
there is any doubt about its condition, drain out a
sample for a double check.
After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
SELECTION OF LUBRICANT
It is important that the proper lubricant be used in
these transmissions. MOPAR
t ATF PLUS (Automatic
Transmission Fluid-Type 7176) should be used to aid in
assuring optimum transmission performance. Fluids of
the type labeled DEXRON II Automatic Transmission
Fluid should be used only if the recommended fluid is
not available. If more than a small amount of Dexron
fluid is used, shudder or shift quality problems may be
encountered. It is important that the transmission
fluid be maintained at the prescribed level using the
recommended fluids.
SPECIAL ADDITIVES
Chrysler Corporation does not recommend the addi-
tion of any fluids to the transmission, other than the
automatic transmission fluid listed above. An excep-
tion to this policy is the use of special dyes to aid in
detecting fluid leaks. The use of transmission sealers
should be avoided, since they may adversely affect
seals.
FLUID AND FILTER CHANGE
When the factory fill fluid is changed, only
fluids of the type labeled MOPAR
t ATF PLUS
(Automatic Transmission fluid) Type 7176 should
be used. A band adjustment and filter change
should be made at the time of the oil change. The
magnet (inside of oil pan) should be cleaned with
a clean, dry cloth.
If the transaxle is disassembled for any reason,
the fluid and filter should be changed, and the
band(s) adjusted.
FLUID DRAIN AND REFILL
(1) Raise vehicle on a hoist (See Lubrication,‘‘Group
0’’). Place a drain container with a large opening, under
transaxle oil pan.
(2) Loosen pan bolts and tap the pan at one corner to
break it loose allowing fluid to drain, then remove the
oil pan.
(3) Install a new filter and gasket on bottom of the
valve body and tighten retaining screws to 5 N
Im (40
inch-pounds).
(4) Clean the oil pan and magnet. Reinstall pan
using new sealant. Tighten oil pan bolts to 19 N
Im
(165 in. lbs.).
(5) Pour four quarts of MOPAR
t ATF PLUS (Auto-
matic Transmission Fluid) Type 7176 through the
dipstick opening.
(6) Start engine and allow to idle for at least one
minute. Then, with parking and service brakes ap-
plied, move selector lever momentarily to each posi-
tion, ending in the park or neutral position.
(7) Add sufficient fluid to bring level to 1/8 inch
below the ADD mark.
Recheck fluid level after transaxle is at normal
operating temperature. The level should be in the HOT
region (Fig. 1).
To prevent dirt from entering transaxle, make cer-
tain that dipstick is full seated into the dipstick open-
ing.
LOCKUP SOLENOID WIRING CONNECTOR
If wiring connector is unplugged, the torque con-
verter will not lock-up (Fig. 2).
ROAD TEST
Prior to performing a road test, be certain that the
fluid level and condition, and control cable adjustments
have been checked and approved.
During the road test, the transaxle should be oper-
ated in each position to check for slipping and any
variation in shifting.
If vehicle operates properly at highway speeds, but
has poor through-gear acceleration, the torque con-
verter stator overrunning clutch may be slipping. If
through-gear acceleration is normal, but abnormally
high throttle opening is required to maintain highway
speeds, the torque converter stator clutch may
Fig. 1 Dipstick and Transaxle Vent
Fig. 2 Lockup Solenoid Wiring Connector
.
TRANSAXLE
21 - 37
have seized. Both of these stator defects require re-
placement of the torque converter.
Observe closely for slipping or engine speed flare-up.
Slipping or flare-up in any gear usually indicates
clutch, band, or overrunning clutch problems. If the
condition is far advanced, an overhaul will probably be
necessary to restore normal operation.
In most cases, the clutch or band that is slipping can
be determined by noting the transaxle operation in all
selector positions. Then comparing which internal
units are applied in those positions. The ‘‘Elements in
Use Chart’’ provides a basis for road test analysis.
The rear clutch is applied in both the ‘‘D’’ first gear
and ‘‘1’’ first gear positions. Also the overrunning clutch
is applied in ‘‘D’’ first gear and the low/reverse band is
applied in ‘‘1’’ first gear position. If the transaxle slips
in ‘‘D’’ range first gear, but does not slip in ‘‘1’’ first gear,
the overrunning clutch is slipping. Similarly, if the
transaxle slips in any two forward gears, the rear
clutch is slipping.
Using the same procedure, the rear clutch and front
clutch are applied in ‘‘D’’ third gear. If the transaxle
slips in third gear, either the front clutch or the rear
clutch is slipping. By selecting another gear which does
not use one of those units, the unit which is slipping
can be determined. If the transaxle also slips in re-
verse, the front clutch is slipping. If the transaxle does
not slip in reverse, the rear clutch is slipping.
The process of eliminating can be used to detect any
unit which slips and to confirm proper operation of
good units. However, although road test analysis can
usually diagnose slipping units, the actual cause of the
malfunction usually cannot be decided. Practically any
condition can be caused by leaking hydraulic circuits or
sticking valves.
Therefore, unless the condition is obvious, like no
drive in ‘‘D’’ range first gear only, the transaxle should
never be disassembled until hydraulic pressure tests
have been performed.
HYDRAULIC PRESSURE TESTS
Pressure testing is a very important step in the
diagnostic procedure. These tests usually reveal the
cause of most transaxle problems.
Before performing pressure tests, be certain that
fluid level and condition, and control cable adjustments
have been checked and approved. Fluid must be at
operating temperature (150 to 200 degrees F.).
Install an engine tachometer, raise vehicle on hoist
which allows front wheels to turn, and position ta-
chometer so it can be read.
Disconnect throttle cable and shift cable from tran-
saxle levers so they can be controlled from outside the
vehicle.
Attach 150 psi gauges to ports required for test being
conducted. A 300 psi gauge (C-3293) is required for
‘‘reverse’’ pressure test at rear servo.
Test port locations are shown in (Fig. 3).
TEST ONE (SELECTOR IN ‘‘1’’)
(1) Attach gauges to ‘‘line’’ and ‘‘low-reverse’’ ports
(Fig. 3).
(2) Operate engine at 1000 rpm for test.
(3) Move selector lever on transaxle all the way
rearward (‘‘1’’ position).
(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise position to
full counterclockwise position.
(5) Line pressure should read 52 to 58 psi with
throttle lever clockwise and gradually increase, as
lever is moved counterclockwise, to 80 to 88 psi.
(6) Low-reverse pressure should read the same as
line pressure within 3 psi.
(7) This tests pump output, pressure regulation, and
condition of rear clutch and rear servo hydraulic cir-
cuits.
ELEMENTS IN USE AT EACH POSITION OF THE SELECTOR LEVER
21 - 38
TRANSAXLE
.
TEST TWO (SELECTOR IN ‘‘2’’)
(1) Attach one gauge to ‘‘line pressure’’ port and ‘‘tee’’
another gauge into lower cooler line fitting to read
‘‘lubrication’’ pressure (Fig 3).
(2) Operate engine at 1000 rpm for test.
(3) Move selector lever on transaxle one ‘‘detent’’
forward from full rearward position. This is selector ‘‘2’’
position.
(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise position to
full counterclockwise position.
(5) Line pressure should read 52 to 58 psi with
throttle lever clockwise and gradually increase, as
lever is moved counterclockwise, to 80 to 88 psi.
(6) Lubrication pressure should be 10 to 25 psi with
lever clockwise and 10 to 35 psi with lever full coun-
terclockwise.
(7) This tests pump output, pressure regulation, and
condition of rear clutch and lubrication hydraulic cir-
cuits.
TEST THREE (SELECTOR IN ‘‘D’’)
(1) Attach gauges to ‘‘line’’ and ‘‘kickdown release’’
ports (Fig. 3).
(2) Operate engine at 1600 rpm for test.
(3) Move selector lever on transaxle two ‘‘detents’’
forward from full rearward position. This is selector
‘‘D’’ position.
(4) Read pressures on both gauges as throttle lever
on transaxle is moved from full clockwise position to
full counterclockwise position.
(5) Line pressure should read 52 to 58 psi with
throttle lever clockwise and gradually increase, as
lever is moved counterclockwise to 80 to 88 psi.
(6) Kickdown release is pressurized only in direct
drive and should be same as line pressure within 3 psi,
up to kickdown point.
(7) This tests pump output, pressure regulation, and
condition of rear clutch, front clutch, and hydraulic
circuits.
TEST FOUR (SELECTOR IN REVERSE)
(1) Attach 300 psi gauge to ‘‘low-reverse’’ port (Fig.
3).
(2) Operate engine at 1600 rpm for test.
(3) Move selector lever on transaxle four ‘‘detents’’
forward from full rearward position. This is selector ‘‘R’’
position.
Fig. 3 Transaxle (Left Side)
.
TRANSAXLE
21 - 39
(4) Low-reverse pressure should read 180 to 220 psi
with throttle lever clockwise and gradually increase, as
lever is moved counterclockwise to 260 to 300 psi.
(5) This tests pump output, pressure regulation, and
condition of front clutch and rear servo hydraulic
circuits.
(6) Move selector lever on transaxle to ‘‘D’’ position to
check that low-reverse pressure drops to zero.
(7) This tests for leakage into rear servo, due to case
porosity, which can cause reverse band burn out.
TEST RESULT INDICATIONS
(1) If proper line pressure, minimum to maximum, is
found in any one test, the pump and pressure regulator
are working properly.
(2) Low pressure in ‘‘D, 1, and 2’’ but correct pressure
in ‘‘R’’ indicates rear clutch circuit leakage.
(3) Low pressure in ‘‘D and R’’ but correct pressure in
‘‘1’’ indicates front clutch circuit leakage.
(4) Low pressure in ‘‘R and 1’’ but correct pressure in
‘‘2’’ indicates rear servo circuit leakage.
(5) Low line pressure in all positions indicates a
defective pump, a clogged filter, or a stuck pressure
regulator valve.
GOVERNOR PRESSURE
Test only if transaxle shifts at wrong vehicle speeds
when throttle cable is correctly adjusted.
(1) Connect a 0-150 psi pressure gauge to governor
pressure take-off point, located at lower right side of
case, below differential cover (Fig. 3).
(2) Operate transaxle in third gear to read pres-
sures. The governor pressure should respond smoothly
to changes in mph and should return to 0 to 3 psi when
vehicle is stopped. High pressure at standstill (above 3
psi) will prevent the transaxle from downshifting.
THROTTLE PRESSURE
No gauge port is provided for throttle pressure.
Incorrect throttle pressure should only be suspected if
part throttle upshift speeds are either delayed or occur
too early in relation to vehicle speeds, with correctly
adjusted throttle cable. Engine runaway on either
upshifts or downshifts can also be an indicator of
incorrect (low) throttle pressure setting, or misad-
justed throttle cable.
In no case should throttle pressure be adjusted until
the transaxle throttle cable adjustment has been veri-
fied to be correct.
CLUTCH AND SERVO AIR PRESSURE TESTS
A ‘‘no drive’’ condition might exist even with correct
fluid pressure, because of inoperative clutches or
bands. The inoperative units, clutches, bands, and
servos can be located through a series of tests by
substituting air pressure for fluid pressure (Fig. 4).
The front and rear clutches, kickdown servo, and
low-reverse servo may be tested by applying air pres-
sure to their respective passages after the valve body
assembly has been removed. To make air pressure
tests, proceed as follows:
Compressed air supply must be free of all dirt
or moisture. Use a pressure of 30 psi.
Remove oil pan and valve body See ‘‘Disassembly-
Subassembly Removal’’.
FRONT CLUTCH
Apply air pressure to front clutch ‘‘apply’’ passage
and listen for a dull ‘‘thud’’ which indicates that front
clutch is operating. Hold air pressure on for a few
seconds and inspect system for excessive oil leaks.
REAR CLUTCH
Apply air pressure to rear clutch ‘‘apply’’ passage and
listen for a dull ‘‘thud’’ which indicates that rear clutch
is operating. Also inspect for excessive oil leaks. If a
dull ‘‘thud’’ cannot be heard in the clutches, place finger
tips on clutch housing and again apply air pressure.
Movement of piston can be felt as the clutch is applied.
KICKDOWN SERVO (FRONT)
Direct air pressure into KICKDOWN SERVO ‘‘ON’’
passage. Operation of servo is indicated by a tightening
of front band. Spring tension on servo piston should
release the band.
LOW AND REVERSE SERVO (REAR)
Direct air pressure into LOW-REVERSE SERVO
‘‘APPLY’’ passage. Operation of servo is indicated by a
tightening of rear band. Spring tension on servo piston
should release the band.
If clutches and servos operate properly, ‘‘no upshift’’
or ‘‘erratic shift’’ conditions indicate that malfunctions
exist in the valve body.
FLUID LEAKAGE-TRANSAXLE TORQUE CON-
VERTER HOUSING AREA
(1) Check for Source of Leakage.
Since fluid leakage at or around the torque converter
area may originate from an engine oil leak, the area
should be examined closely. Factory fill fluid is dyed
red and, therefore, can be distinguished from engine
oil.
(2) Prior to removing the transaxle, perform the
following checks:
When leakage is determined to originate from the
transaxle, check fluid level prior to removal of the
transaxle and torque converter.
21 - 40
TRANSAXLE
.
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