1997 MITSUBISHI TRITON automatic transmission

GENERAL ± How to Use This Manual00-3
MODEL INDICATIONS
The following abbreviations are used in this manual for classification of model types.
M/T: Indicates the manual transmission, or models equipped with the manual transmission.
A/T: Indicates the automatic transmission, or models equipped with the automatic transmission.
SOHC: Indicates an engine with the single overhead camshaft, or a model equipped with such
an engine.
MPI: Indicates the multi-point injection, or engines equipped with the multi-point injection.
DIESEL: Indicates a diesel engine, or models equipped with such an engine.
2WD: Indicates the rear wheel-drive vehicles.
4WD: Indicates the 4 wheel-drive vehicles.

ENGINE COOLING ±
General Information/
Service Specifications/Lubricant/Sealants14-2
GENERAL INFORMATION14100010125
The cooling system is designed to keep every part
of the engine at appropriate temperature in
whatever condition the engine may be operated.
The cooling method is of the water-cooled, pressure
forced circulation type in which the water pump
pressurizes coolant and circulates it throughout the
engine. If the coolant temperature exceeds the
prescribed temperature, the thermostat opens to
circulate the coolant through the radiator as well
so that the heat absorbed by the coolant may be
radiated into the air.The water pump is of the centrifugal type and is
driven by the drive belt from the crankshaft.
The radiator is the corrugated fin, down flow type.
ItemsSpecifications
RadiatorPerformance kJ/h4G63 114,700
4G63 126,800
4G64, 4D56 <2WD>170,000
4D56 <4WD>227,300
Automatic transmission oil coolerPerformance kJ/h4G63 6,400
4D56 6,300
SERVICE SPECIFICATIONS14100030121
ItemsStandard valueLimit
High pressure valve opening pressure of radiator cap kPa75 ± 10565
Range of coolant antifreeze concentration of radiator %30 ± 60±
ThermostatValve opening temperature of thermostat
C82 + 1.5±
Full-opening temperature of thermostat
C95±
Valve lift (at 95
C) mm4G6, 4D56 <4WD>8.5 or more±
4D56 <2WD>8 or more±
LUBRICANT14100040100
ItemsQuantity

HIGH QUALITY ETHYLENE GLYCOL ANTIFREEZE COOLANT4G637.4
4G64, 4D56 <2WD>7.7
4D56 <4WD>7.8
SEALANTS14100050110
ItemsSpecified sealantRemarks
Cylinder block drain plug3M Nut Locking Part No. 4171 or equivalentDrying sealant
Water by-pass fitting <4G6>Mitsubishi Genuine Parts No. MD970389 or
equivalentSemi-drying sealant

AUTOMATIC TRANSMISSION ±
General Information/
Service Specifications23-2
GENERAL INFORMATION23100010141
ItemsVehicles with 4G63 engineVehicles with 4D56 engine
Transmission modelR4AW2-6V4AW2-6
Type4-speed full automatic4-speed full automatic
Gear ratio1st2.8262.826
2nd1.4931.493
3rd1.0001.000
4th0.7300.688
Reverse2.7032.703
Transfer type±2-speed
Gear ratioHigh±1.000
Low±1.925
Speedometer gear ratio (driven/drive)22/625/8
SERVICE SPECIFICATIONS23100030130
ItemsStandard value
Distance between inner cable stopper and end of outer cable <4G63> mm0 ± 1
Distance between inner cable stopper and end of outer cable <4D56> mm34 ± 35
Lock-up solenoid valve coil resistance (at 20
C) WApprox. 13
Stall speed r/min4G632,100 ± 2,400
4D562,300 ± 2,600
Governor pressure kPa1,000 r/min137 ± 166
2,000 r/min245 ± 284
3,200 r/min402 ± 460
Line pressure kPaAt idle speedD range480 ± 558
R range735 ± 852
At stall speedD range1,019 ± 1,195
R range1,519 ± 1,911
Operation temperature of engine coolant
temperature switch
C
On (continuity)50 + 3
tem erature switch
C
Off (no continuity)43
Clearance between shift lever guide and steering column mm2.4 ± 3.6

AUTOMATIC TRANSMISSION ± Troubleshooting23-4
TROUBLESHOOTING23100760152
STANDARD FLOW OF DIAGNOSIS TROUBLESHOOTING
Automatic transmission malfunctions may be caused by the following conditions.
(1) Improper maintenance and adjustment
(2) Shift control system malfunction
(3) Mechanical malfunctions
(4) Hydraulic malfunctions
(5) Poor engine performance
Troubleshooting in the event of any such malfunctions should begin by checking fluid level, ATF condition,
manual linkage adjustment, throttle control cable adjustment and other conditions whose deviation from
standards can be readily known. Then, road test shall be performed to determine whether or not the
problem has been corrected or more diagnosis is necessary. If the problem still persists after these tests
and corrections, hydraulic tests should be performed for further troubleshooting.
Road test (guess what causes malfunc-
tion.)
Check how A/T works in each drive
range to find a defective system.
A/T control component inspection
Check the throttle cable, inhibitor switch,
overdrive switch, overdrive solenoid
valve, overdrive control relay, defective
switch, engine coolant temperature
switch and vehicle speed sensor.
Torque converter stall test (Inspection
of engine performance and mechanical
function)
Check the engine performance, torque
converter operation and clutch and
brake sliding performance.
Hydraulic pressure test (Inspection of
hydraulic control mechanism)
Measure the fluid line pressure and
check for malfunctions of the oil pump
or regulator valve and for oil leaks.
Oil leak inspection
Visually check gaskets and oil seals for
leaks.
Adjustment of basic inspection items
ROAD TEST 23100780158
Prior to performing road test, be sure to make basic checks including check and adjustment of fluid
level and condition and adjustment of the throttle cable. For road test, the transfer must be placed in
the 2H (2WD-high) position. In road test, various changes such as slips in transmission and shifting
conditions are checked and the transmission operation at each shift position must have been checked.

AUTOMATIC TRANSMISSION ± Troubleshooting23-5
D RANGE TEST
Correct
Carry out the TEST 1 again.
Ye s
Check the shifting points.Incorrect
Line pressure malfunction

Governor malfunction

Incorrect throttle cable adjustment
Ye s
Does the upshift from 3-speed to 4-speed occur? (with throttle
valve opening under 85%)No
3 ± 4 shift valve malfunction

Governor malfunction

Overdrive switch or overdrive solenoid malfunction

Overdrive control relay malfunction

Engine coolant temperature switch malfunction <4G6>
Ye s
Does the upshift from 2-speed to 3-speed occur?No
2 ± 3 shift valve malfunction

Governor malfunction
NG
Does the upshift from 1-speed to 2-speed occur?No
1 ± 2 shift valve malfunction

Governor malfunction
TEST 1
Start with throttle valve opened (50 % and full), and check upshift
from 1-speed  2-speed, 2-speed 3-speed and 3-speed 
4-speed. Check that shifting points match shift pattern.OKTEST 2
Correct
Carry out TEST 2 again.
Ye s
Check the shifting point.Incorrect
Line pressure malfunction

Governor malfunction

Detent regulator valve malfunction
NG
Does the downshift occur?No
Shift valves malfunction

Governor malfunction

Overdrive switch or overdrive solenoid malfunction

Overdrive control relay malfunction

Detection switch malfunction
TEST 2
Kickdown traveling at 2-speed, 3-speed and 4-speed. Check that
possible kickdown vehicle speed limit at 2-speed  1-speed,
3-speed  1-speed, 3-speed  2-speed, or 4-speed  1-speed,
4-speed  2-speed, 4-speed  3-speed conforms with the shift
pattern.OKTEST 3
Correct
Carry out TEST 3 again.
Ye s
Check the Shifting point.Incorrect
Incorrect throttle cable adjustment

Governor malfunction

Line pressure malfunction

Low coast modulator valve malfunction
NG
Does the downshift from 2-speed to 1-speed occur?No
1 ± 2 shift valve malfunction

Governor malfunction
TEST 3
When traveling in 3-speed or 4-speed, release accelerator pedal
and shift to L. Check that 3-speed  2-speed or 4-speed  3-speed
takes place immediately and 2-speed  1-speed downshift con-
forms with shift pattern.OKTEST 4

AUTOMATIC TRANSMISSION ± Troubleshooting23-6
Ye s
Carry out TEST 4 again.
Ye s
Does the engine brake function in L range?NoBrake No. 3 malfunction
No
Does the engine brake function in 2 range?NoBrake No. 1 malfunction
TEST 4
When traveling in 3-speed or 4-speed, shift to 2 and L. Does the
engine brake function in each range?Ye sTEST 5
Ye s

High line pressure

Accumulator malfunction

Check ball malfunctionCarry out TEST 5 again.
TEST 5
Is there abnormal noise(s) during acceleration and deceleration?
Is there shocks when slipping and changing speed?NoTEST 6
Ye s

Incorrect torque converter installation

Oil pump malfunction

Shifting gear not meshing correctly

Incorrect drive plate installationCarry out TEST 6 again.
TEST 6
Is there abnormal noise(s) or vibration when traveling in 3-speed
or 4-speed?NoTEST 7
NOTE
Abnormal noises and vibrations are often caused by an unbalanced propeller shaft, differential, tyre,
torque converter, engine, etc. Extremely thorough inspection is therefore required.
Ye s
Carry out TEST 7 again.
Ye s
Does lock up go on, off?No
Lock up signal valve malfunction

Lock up relay valve malfunction

Lock up clutch malfunction
No
Does the moment when lock up turns ON or OFF conform with
the shift pattern?No
Governor malfunction

Line pressure malfunction
TEST 7
Check that lock up ON, OFF. Does the shifting points conform
with shift pattern?Ye sCarry out the road test in 2 range.
NOTE
(1) Determine the moment when lock up turns ON by decreased engine r/min or by a slight shock back
and forth.
(2) Determine the moment when lock up turns OFF by increased engine r/min.
(3) Check lock up condition by pumping the accelerator slightly. If engine r/min rises in accordance with
throttle valve opening size, determine that the lock up is OFF, if not, determine it ON.
(When lock up is OFF, drive power is transferred through the fluid in the torque converter and therefore,
when the accelerator pedal is depressed, slipping occurs inside the torque converter with a resulting
large increase in engine r/min.)

AUTOMATIC TRANSMISSION ± Troubleshooting23-7
2 RANGE TEST
Correct
Carry out TEST 1 again.
Ye s
Check the shifting point.Incorrect
Misadjusted throttle cable

Governor malfunction

Line pressure malfunction
No
Does the upshift from 1-speed to 2-speed occur?No
1 ± 2 shift valve malfunction

Governor malfunction
TEST 1
Start with throttle valve opening at 50% and full. Does the shifting
points conform with the shift pattern when upshifting from 1-speed

2-speed?Ye sTEST 2
Ye s
Carry out TEST 2 again.
NG
Does the downshift occur and is the shifting point correct?No
Detent regulator valve malfunction

Governor malfunction

Misadjusted throttle cable

1 ± 2 shift valve malfunction

Line pressure malfunction
TEST 2
Kickdown and check that possible kickdown vehicle speed limit
at 2-speed
1-speed conforms with shift pattern.OKCarry out road test in L range.
L RANGE TEST
No
Carry out road test in R range.
TEST 1
Does the transmission upshift to 2-speed?Ye s
Low coast modulator valve malfunction

Governor malfunction

Low line pressure
R RANGE TEST
Ye s
Carry out road test in P range.
TEST 1
Is the engine r/min by stall test correct?No
Brake No. 3 malfunction

Overdrive clutch or direct clutch malfunction

Overdrive one-way clutch malfunction

Low line pressure
P RANGE TEST
Ye s
End
TEST 1
Park vehicle on an incline (more than 5) and release parking
and service brakes. Does the vehicle move?No
Park mechanism malfunction

Misadjusted shift lever

AUTOMATIC TRANSMISSION ± On-vehicle Service23-19
CONVERTER STALL TEST 23100540138
In this test, the engine maximum speed when the
torque converter stalls with the shift lever in the
ªDº or ªRº range is measured to check operation
of the torque converter, starter and one-way clutch
and check holding performance of the transmission
clutch (including brake).
Caution
Do not stand in front or at rear of the vehicle
during this test.
(1) Check the transmission fluid level. The fluid
temperature should be at the level after normal
operation (70 ± 80
C). The engine coolant
temperature should also be at the level after
normal operation (80 ± 90
C).
(2) Apply chocks to the rear wheels (right and left).
(3) Mount an engine tachometer.
(4) Apply fully the parking and service brakes.(5) Start the engine.
(6) With the selector lever in the ªDº range, fully
depress the accelerator pedal and read off the
engine maximum speed.
Standard value:
2,100 ± 2,400 r/min <4G63>
2,300 ± 2,600 r/min <4D56>
NOTE
When doing so, do not keep the engine running
with throttle full open for more than 5 seconds.
If two or more stall tests are needed, place
the selector lever in the ªNº position and run
the engine at about 1,000 r/min to allow the
transmission fluid to cool before another stall
test.
(7) Place the selector lever in the ªRº range and
perform the test as above.
JUDGEMENT OF STALL TEST RESULTS
Stall speed in ªDº and ªRº range is equal to each other
but lower than the nominal value.(1) Engine output is low.
(2) Starter one-way clutch is faulty. (Faulty torque
converter is suspected if it is lower than nominal
by more than 600 r/min)
Stall speed in ªDº range is higher than nominal.(1) Overdrive clutch slipping
(2) Overdrive one-way clutch faulty
(3) Forward clutch slipping
(4) One-way clutch No. 2 faulty
(5) Low line pressure
Stall speed in ªRº range is higher than nominal.(1) Overdrive clutch slipping
(2) Overdrive one-way clutch faulty
(3) Direct clutch slipping
(4) Brake No. 3 slipping
(5) Low line pressure