1991 MITSUBISHI 3000GT low oil pressure

23-40AUTOMATIC TRANSAXLE - Troubleshooting
REMEDIAL ACTION TO TAKE FOR INADEQUATE OIL PRESSURESymptom
Possible cause
Remedy
1. All line pressuresa. Plugged oil filter
are low (or high).b. Improperly adjusted regulatora. Visually check oil filter and replace it if plugged.
valve line pressure
b. Measure line pressure (2) (KID brake pres-
NOTE:sure) and readjust line pressure if it is
Line pressures areout of specifications.
@.@.@).@.@and @shown onc. Defective valve body assemblyOr, replace valve body assembly.
the Standard Oil
Pressure Table
on the preceding
paw.
d. Valve body left loose
e. Improper oil pump delivery.
pressurec. Replace valve body assembly.d. Torque valve body clamp bolt and mounting
bolt to specification.
e. Check oil pump gear side clearance and
replace oil pump assembly as necessary.
2. Improper reducing
a. Plugged reducing pressure
a. Disassemble valve body assembly to check
pressurecircuit filter (L-shaped)
b. Improperly adjusted reducingfilter and replace filter if it is plugged.
b. Measure reducing pressure @and readjust
pressure
c. Defective valve body assemblyas necessary.
c. Replace valve body assembly.
3. Improper K/D
brake pressure
(application)a. Defective seal ring
@ and D-ring @of K/D servo piston and seal ringa. Disassemble K/D servo and check seal ring
@of sleeveand D-ring for damage. Replace seal ringb. Defective valve body assemblyor D-ring if damaged or scratched.
b. Replace valve body assembly.
4. Improper KIDbrake pressure
(release)
J. Improper front
clutch pressurea. Defective seal ring
@ and D-ring @of K/D servo piston and seal ringa. Disassemble KID servo and check seal ring
@ of sleeveand D-ring for damage. Replace seal ring
b. Defective valve body assemblyor D-ring if damaged or scratched.b. Replace valve body assembly.
a. Defective seal ring @and D-ring
@of K/D servo piston and seal ringa. Disassemble K/D servo and check seal ring
@ of sleeveand D-ring for damage. Replace seal ringb. Defective valve body assemblyor D-ring if damaged or scratched.
c. Worn front clutch piston andb. Replace valve body assembly.c. Disassemble transaxle and check front clutch
retainer or defective D-ring @or seal ring @piston and retainer for wear and D-ring and
seal ring for damage. Replace piston, retainer,
D-ring, or seal ring as necessary.
3. Improper
rear clutch
pressure
7. Improper
end clutch
pressurea. Defective D-ring
@ of piston,
seal ring @ of retainer,
and seal ring @and D-ring @of input shaft
b. Defectrve valve body assembly
a. Defective seal ring
0. D-ring 0,and oil seal (iJ of end clutch
b. Defective valve body assemblya. Disassemble rear clutch and check input shaft
D-ring, center support seal ring, and piston
D-ring; replace if damaged or scratched.
b. Replace valve body assembly.
a. Disassemble the end clutch and check piston oil
seal, D-ring, and center support seal ring;
replace if damage or scratches are evident.
b. Replace valve body assembly.
8. Improper
low-reverse
brake pressurea. Damaged O-ring between valve
body and transmission
b. Defective valve body assemblyc. Defective D-ring @of piston
or O-ring
@I of center supporta. Remove valve body assembly and check O-ring
on top of upper valve body; replace if damage
or scratches are evident.
b. Replace valve body assembly.
c. Disassemble transaxle and check D-ring and
O-ring; replace if damage or scratches are eviden
3. Improper
torque converter
pressurea. Sticking damper clutch controla. Check damper clutch system and DCCSV
solenoid valve (DCCSV) or damper
for operation.
clutch control valve
b. Plugged or leaky oil cooler and
pipingsb. Repair or replace cooler or pipings.
c. Damaged seal ring @of input shaftc. Disassemble transaxle and check seal ring;
d. Defective torque converterreplace if it is damaged.
d. Replace torque converter.
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d

AUTOMATIC TRANSAXLE - Service Adjustment Procedures23-49
1(9) Install valve body and oil temperature sensor.
Bolt A
= Length 18 mm (.709 in.)
Bolt B
= Length 25 mm (.984 in.)
Bolt C
= Length 40 mm (1.575 in.)
CautionSecure solenoid valve and oil temperature sensor
harness at locations shown.
(1O)lnstall oil filter.(1l)lnstall new oil pan gasket and oil pan.
(12)Add the specified amount of ATF.
(13)Carry out hydraulic test.
Readjust as necessary.
REDUCING PRESSURE ADJUSTMENTh323FfADWhen multi-use tester is not used
(1) Following the same steps as those in line pressure
adjustment, remove parts up to oil filter.
There is no need to remove valve body.
(2) Turn adjusting screw of lower valve body to obtain the
specified reducing pressure. Turn it counterclockwise to
increase the pressure.
Standard value:425 f 10 kPa (60 f 1 psi)
Oil pressure change for
each turn of adjusting screw:45 kPa (6 psi)(3) In the same way as in line pressure adjustment,
/nstall oil
filter and oil pan.
(4) Perform hydraulic test.
Adjust as necessary.
When multi-use tester is used
(1) Adjust to obtain the specified K/D brake pressure when PC
solenoid is energized at duty 50% with the multi-use tester.
Standard value:275 kPa (39 psi)
Oil pressure change for
each turn of adjusting screw:50 kPa (7 psi)(2) After adjustment has been made, check that the recuding
pressure is in the range 360
- 480 kPa (51 - 68 psi).
Caution
This adjustment should be made with oil temperature70
- 80°C (160 - 180°F).
The adjustment made with high oil temperature couldresult in improper adjustment due to a line pressure
drop at idle.
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23-82AUTOMATIC TRANSAXLE - Transaxle Assembly
(21 jlnstall the special tool to the center support, fit new O-rings
(at two places), and press the center support into the
transaxle case.
Caution1. Coat the O-rings with ATF and align oil holes.‘LJ ’2. Install with care not to allow the wave spring to
shift its position.
(22)Fit the snap ring.
(23)Using a feeler gauge, measure the end play in low-reverse
brake. Select a pressure plate to obtain the specified end
play.Standard value: 1.0
- 1.2 mm (.039 - .047 in.)
(24)lnstall the air exhaust plug and mount the plug.
(25)lnstall the anchor rod.
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23408AUTOMATIC TRANSAXLE - Valve Body
VALVE BODY
DISASSEMBLY AND REASSEMBLYViewed from AhV3LOAM
l + 14. Relief springl * 15. Steel ballI)* 16. Oil filterl * 17. Upper valve body sub assembly** 18. Steel balll + 1’9. Teflon ball_ ^l * 20. N-D plate21. Block
TFA0523
1. Manual valvel *2. Pressure control solenoid valve**3. Damper clutch control solenoid valvel *4. Shift control solenoid valve “A”l a5. Shift control solenoid valve “B”
6. Clamp
7. Valve stopper
8. N-D control sleeve
9. N-D control valve
*4 10. Lower valve body sub assembly
11. Lower separating plate
12. Nut
13. Jet
22. Upper separating plate
23. Intermediate plate
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FRONT SUSPENSION - Special Tools / Troubleshooting
SPECIAL TOOLS
L
L
Removalof the lower arm ball joint and
Wheel alignment
gauge attachment
Measurement of the wheel alignment
Spring compressorCompression of the front coil spring
MB990799-01Ball joint remover
and installerInstallation of the dust shield
TROUBLESHOOTINGM33EBAA
SymptomProbable causeRemedy
Steering wheel is heavy,Suspension malfunctionvibrates or pulls toBall joint
Adjust orreplace
one sideCoil springWheel alignment
Unbalanced or worn tiresAdjust or replace
Excessive vehicleBroken or deteriorated stabilizer
rollingShock absorber malfunctionReplace
Poor ridingImproper tire inflation pressureAdjust
Broken or deteriorated coil spring
Shock absorber malfunctionReplace
Inclination of vehicleBroken or deteriorated coil springReplace
NoiseLack of lubricationLubricate
Looseness and wear of each partRetighten or replace
Broken coil spring
Shock absorber malfunction
ReplaceTSB Revision
I

37A-1
STEERING
CONTENTSM37AA-A
POWER STEERING GEAR BOX*....................17Steering Wheel Return to Center
Check................................................................8
POWER STEERING HOSES................................32Tie Rod End Ball Joint Startinq Torque
POWER STEERING OIL PUMP. .._....................28Check. . . . . . . . .._.............................. r . . . . . . . . ..I . . . . . .6Tie Rod End Ball Joint Variation Check
SERVICE ADJUSTMENT PROCEDURES5(Shaft direction)................................................5........
Bleeding............................................................10V-Belt Tension Check........................................8
Fluid Level Check............................................9SPECIAL TOOLS....................................................3Fluid Replacement
............................................9
/
bOil Pressure Switch Check
SPECIFICATIONS2............................12................................................Oil Pump Pressure Test
....................................1 1General Specifications....................................2Stationary Steering Effort Check
....................8Lubricants............................................................3Steering Angle Check
5Sealant and Adhesives....................................3........................................Steering Wheel Centering
6Service Specifications....................................2................................Steering Wheel Free Play Check
....................5STEERING WHEEL AND SHAFT*....................13
SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
(1)A Supplemental Restraint System (SRS), which uses a driver-side air bag, has been installed in the 3000GT.(2)The SRS includes the following components: impact sensors, SRS diagnosis unit: SRS warning light, air bagmodule, clock spring, interconnecting wiring. Other SRS-related components (that may have to be
removed/installed in connection with SRS service or maintenance) are indicated in the table of contents byan asterisk (*).
WARNING!(I)Improper service or maintenance of any component of the SRS, or any SRS-related component, can lead to
personal injury or death to service personnel (from inadvertent firing of the air bag) or to the driver (from
rendering the SRS inoperative).
(2) Service or maintenance of any SRS component or SRS-related component must be performed only at an
authorized MITSUBISHI dealer.(3) MITSUBISHI dealer personnel must thoroughly review this manual, and especially its GROUP 52B
-Supplemental Restraint System (SRS), before beginning any service or maintenance of any component of theSRS or any SRS-related component.

37B-24-WHEEL STEERING SYSTEM (4WS) -Specifications / Special Tools
SPECIFICATIONS
GENERAL SPECIFICATIONSM37CA-B
Items
Power steering gear box
Type
Oil pump
Type
Displacement
cm”/rev. (cu.in./rev.)
Relief set pressure
MPa (psi)
Rear oil pump
Type
Displacement
cm’/rev. (cu.in./rev.)
Relief set pressure
MPa (psi)
Power cylinder
Type
Strokemm (in.)
Specifications
Rack and pinion
Vane type
9.6 (0.59)
8 (1,138)
Vane type
3.3 (0.20)
4 (569)
Hydraulic double action type
20 i.78) [one side 10 (.39)1
SERVICE SPECIFICATIONSM37CEB
Items
Standard value
Specifications
Rear oil pump displacement [at speedometer reading of
31 mph (50 km/h) for 30 seconds]liter (qts.)
Power cylinder ball joint rotation starting torqueNm (in.lbs.)
Power cylinder tie rod swing torqueN (Ibs.) [Nm (in.lbs.)]
Power cylinder slide resistanceN (Ibs.)
Approx. 1 .O (1.06)
0.5 (4) or less
9 - 55 (2 - 12) IO.5 - 3.0 (4 - 26)l
67 (15) or less
LUBRICANTSM37CD.B
,II
Items
Power steering fluid
Dust cover
Specified lubricant
MITSUBISHI PLUS
ATFiAutomatic Trans-mission fluid “DEXRON” or “DEXRON II”
‘Silicone grease
Quantity
1.45 liter (1.53 qts.)
As requiredSPECIAL TOOLS
M37DA-6
MB990993-01Power steering oilpressure gauge
Measurement of fluid flow volumeTSB Revision

4-WHEEL STEERING SYSTEM (4WS) - Troubleshooting
TROUBLESHOOTING
37B-3
M37EMKBefore inspecting, check the following items:
l Oil pump drive belt tension
lEnsure that the suspension has not been mod-@Power steering fluid level, and air in the system
ified
l Engine
Idle soeed and even idle
lTire and wheel size, specifications, air pressure,
l Oil leakage
balance and amount of wear
l Steering wheel type
l Wheel alignment
Malfunction symptom
4WS does not operateMalfunctioning system
Power cylinderInspection item
Tie rod swing torque
Power cylinder slide resistance
Rear oil pump
Flow volume check
Control valve
-
Poor steering feelingSteering gears and linkage
Rack cracks or deformationFeeling of friction in steering
Poor steering return
Steering wheel efforts
excessive
Control valve
Oil leakage from control valve jornt
Rear wheels cannot be
steered
Poor rear wheels return
Hydraulic pressure for rear
wheel is constantly high
Long rear wheel steering
delayPoor steering response
Poor steering returnPower cylinder
Oil lineOil reservoir
Control valve
Power cylinder
Rear oil pump
Power cylinder
Oil leakage from piston rod
Pressure hose breakage
Oil reservoir deformation or oil leakage
Stuck control valve spool
Stuck power cylinder
Relief valve remains open
Excessive power cylinder friction-
Looseness in power cylinder tie rod ball jo.int
Ball joint dust cover cracks
Poor rear wheel steeringresponsePoor rear wheel steeringrange
Poor steerability (extremetire wear)Control valve
Power cylinder
Rear oil pump
Power cylinder
Oil leakage from control valve spool
Oil leakage from power cylinder
Extreme oil pump internal wear
Tie rod length improperly adjusted after toe-inadjustment
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