Chrysler DODGE D150 1993 Service Manual page 1086

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AUTOMATIC TRANSiISSiOi-32RH/38RH/37RH/42RH/4eRH 21 - 81
AUTOMATIC TRANSMISSION DIAGNOSIS AND TESTING
INDEX
page
Air Testing Clutch and Band Operation 91
Analyzing the Road Test 87
Converter Housing Fluid Leak Diagnosis
. . . . . . . 92
Converter Stall Test 90
Diagnosis Charts and Hydraulic Flow Diagrams . . 95
Fluid Contamination 86
Fluid Level and Condition 85
GENERAL INFORMATION
The diagnosis and testing information in this sec­
tion applies to three and four speed models alike. Di­
agnosis and test procedures apply to all models
except where indicated. Diagnosis information t h a t
only applies to 42RH/46RH models is noted.
Automatic transmission problems can be a result of
poor engine performance, incorrect fluid level, incor­
rect linkage adjustment, band or hydraulic control
pressure adjustments, hydraulic system malfunctions
or electrical/mechanical component malfunctions.
Begin diagnosis by checking t h e easily accessible
items such as: fluid level and condition, linkage ad­
justments and electrical connections on 4-speed mod­
els. A road test will determine if further diagnosis is
necessary.
Procedures outlined in this section should be per­
formed in the following sequence to realize t h e most
accurate results:
• Preliminary diagnosis
• Fluid Level and condition
• Linkage Adjustment
• Road test
• Hydraulic pressure test
• Stall test
• Air pressure tests
• Leak Tests
• Analyze test results and consult diagnosis charts
PRELIMINARY DIAGNOSIS
Two basic procedures are required. One procedure
for vehicles t h a t are driveable and a n alternate pro­
cedure for disabled vehicles (will not back up or
move forward).
Vehicle Is Driveable
(1) Check fluid level and condition.
(2) Adjust throttle and gearshift linkage if com­
plaint was based on delayed, erratic, or harsh shifts.
(3) On 4-speed models, check electrical connections
at dash switch and transmission case. Turn control
switch to ON position before proceeding.
(4) Road test and note transmission operating
characteristics.
page
Gearshift Linkage 8 7
General Information 8 5
Hydraulic Pressure Test 8 8
Overdrive Fourth Gear Electrical Controls . . . . . . 8 6
Preliminary Diagnosis 8 5
Road Test 8 7
Throttle Valve Cable 8 6
(a) If acceleration is sluggish, or if abnormal
throttle opening is needed to maintain normal
speeds with a properly tuned engine, perform a
stall test to check converter clutch operation.
(b) On 42RH/46RH, if fourth gear upshift does
not occur, check overdrive solenoid and switch wir­
ing for opens, shorts, grounds.
(c) If slippage and engine flare is noted, perform
hydraulic pressure test and air pressure test to
check clutch-band-governor operation.
Vehicle Is Disabled
(1) Check fluid level and condition.
(2) Check for broken, disconnected throttle link­
age.
(3) Check for cracked, leaking cooler lines, or
loose, missing pressure port plugs.
(4) Raise vehicle, start engine, shift transmission
into gear and note following:
(a) If propeller shafts t u r n but wheels do not,
problem is with differential or axle shafts.
(b) If propeller shafts do not turn and transmis­
sion is noisy, stop engine. Remove oil pan, and
check for debris. If pan is clear, remove transmis­
sion and check for damaged drive plate, converter,
oil pump or input shaft.
(c) If propeller shafts do not turn and transmis­
sion is not
noisy, perform hydraulic pressure test to deter­
mine if problem is a hydraulic or mechanical.
FLUID LEVEL AND CONDITION
(1) Place vehicle on level surface. This is impor­
t a n t for a n accurate reading.
(2) Do not check level until fluid is a t normal op­
erating temperature of approximately 82°C (180°F).
This is necessary to avoid false readings which could
produce under or over fill condition,
(3) Fully apply parking brakes.
(4) Start and r u n engine at curb idle speed. Then
shift transmission through all gear ranges and back
to Neutral.
(5) Clean top of filler tube and dipstick to keep dirt
out of tube.