1998 MITSUBISHI LANCER EVOLUTION IV Workshop Manual

REAR AXLE – Troubleshooting 27-23
INSPECTION PROCEDURE 4
Rear tires are noisy during low-speed cornering.
Probable cause
The hydraulic unit or torque transfer differential is probably defective.
Defective hydraulic unit

Defective torque transfer differential
NOTE
This symptom is limited only when the diagnosis code is correct.
NG
Replace the hydraulic unit.
NG
Replace the torque transfer differential.
Check the trouble symptom.
NG
Replace AYC fluid.
OK
Correct
Check the trouble symptom.NO
Replace the torque transfer differential.
OK
Is foreign matter trapped in the hydrau-
lic line?YES
Repair
Check the AYC for operation.OKCheck the AYC fluid.
NG
Check hydraulic pressure.NGBleed the system of air.

REAR AXLE – Troubleshooting 27-24
7. CHECK AT AYC-ECU TERMINALS
7-1 TERMINAL VOLTAGE LISTING
(1) The voltage is to be measured across each terminal and ground terminal.
(2) Fig. below shows the arrangement of the terminals.
Terminal
No.Check itemCheck requirementNormally
1Lateral acceleration sensorIgnition switch: ON2.4 – 2.6 V
(horizontal position)
2Longitudinal acceleration
sensor ground
Lateral acceleration sensor
groundAt all times0 V
3Longitudinal acceleration
sensorIgnition switch: ON2.4 – 2.6 V
(horizontal position)
4Steer sensor (ST-2)Engine: Idle speed
Turn steering wheel slowly.0 V ↔ approx. 3 V
flashing
5Steer sensor (ST-1)Engine: Idle speed
Turn steering wheel slowly.0 V ↔ approx. 3 V
flashing
6*1FR wheel speedVehicle stationary1 V or less
Forward vehicle slowly.0 – 5 V
7*1FL wheel speedVehicle stationary1 V or less
Forward vehicle slowly.0 – 5 V
8*1RR wheel speedVehicle stationary1 V or less
Forward vehicle slowly.0 – 5 V
9*1FL wheel speedVehicle stationary1 V or less
Forward vehicle slowly.0 – 5 V
10Diagnosis selection inputBattery voltage
11Stop lamp switchIgnition switch:
ON
Stop lamp switch: ONBattery voltage
ON
Stop lamp switch: OFF1 V or less
12*1ABS monitorWhen ABS monitor is activatedBattery voltage
When ABS monitor is deactivated1 V or less
17Steer sensor (ST-N)Engine:
Idle speed
Steering wheel: Neutral position0.5 V or less
Idle speed
Steering wheel: Turned 90 from
neutral position2.5 – 3.5 V

REAR AXLE – Troubleshooting 27-25
Terminal
No.Normally Check requirement Check item
18TPSIgnition switch:
ON
Accelerator pedal: Fully closed0.3 – 1.0 V
ON
Accelerator pedal: Fully open4.5 – 5.0 V
23Diagnosis data input/output1 V or less
24Idle position switchIgnition switch:
ON
Accelerator pedal: Fully closed2 V or less
ON
Accelerator pedal: Fully open4.5 – 5.0 V
25Accumulator pressure
switchIgnition switch:
ONAccumulator internal pressure:
Low2 V or less
Accumulator internal pressure:
HighBattery voltage
26ECU groundAt all times0 V
31AYC-ECU power supplyIgnition switch: ONBattery voltage
Ignition switch: OFF0 V
35AYC motor relayIgnition switch:
ON
When motor is energizedBattery voltage
ON
When motor is deenergized2 V or less
36AYC warning lampIgnition switch:
ON
When lamp is OFFBattery voltage
ON
When lamp is ON2 V or less
37Directional control valve
(right)
Ignition switch:
ON
Right clutch: ONBattery voltage
(right)ON
Right clutch: OFF0 V
38Proportioning valveIgnition switch:
ONAYC-ON0 V to battery volt-
age
AYC-OFF0 V
39ECU backup power supplyAt all timesBattery voltage
45Directional control valve
(left)
Ignition switch:
ON
Left clutch: ONBattery voltage
(left)ON
Left clutch: OFF0 V
46ECU groundAt all times0 V
NOTE
*1: Indicates the vehicles with ABS.

REAR AXLE – Troubleshooting 27-26
7-2 LISTING OF RESISTANCE AND CONTINUITY ACROSS CONNECTOR TERMINALS ON
HARNESS SIDE
(1) Measure the resistance and check for continuity with the ignition switch in the “OFF” position and
AYC-ECU connector disconnected.
(2) Measure the resistance and check for continuity across terminals listed below.
(3) Fig. below shows the arrangement of terminals.
Terminal No.Signal nameNormally
2 – body groundLongitudinal acceleration sensor ground, lateral acceleration sensor groundConducting
26 – body groundECU groundConducting
35 – body groundAYC motor relayConducting
37 – body groundDirectional control valve (right)15.4 – 16.4 Ω
38 – body groundProportioning valve3.4 – 4.0 Ω
45 – body groundDirectional control valve (left)15.4 – 16.4 Ω
46 – body groundECU groundConducting
6 – 19*2Speed sensor (front, RH)1.4 – 1.8 Ω
7 – 20*2Speed sensor (front, LH)1.4 – 1.8 Ω
8 – 21*2Speed sensor (rear, RH)1.4 – 1.8 Ω
9 – 22*2Speed sensor (rear, LH)1.4 – 1.8 Ω
NOTE
*2: Indicates the vehicles without ABS.

REAR AXLE – On-vehicle Service 27-27
ON-VEHICLE SERVICE

1. REAR AXLE TOTAL BACKLASH CHECK
If the drive system roars or the vehicle vibrates, use the
following procedure to measure total backlash in the rear
axle. Based on the measurement taken, determine whether
the differential carrier assembly needs to be removed or not.
(1) Place the shift lever in the neutral position and operate
the parking brake.
(2) Turn the propeller shaft fully clockwise and make an
alignment mark on the companion flange dust cover and
gear carrier.
(3) Turn the propeller shaft fully counterclockwise and
measure the deviation between the alignment marks.
Limit: 5 mm
(4) If the backlash exceeds the limit, replace the differential
carrier assembly.
2. GEAR OIL LEVEL CHECK
2-1 DIFFERENTIAL
(1) Remove the filler plug.
(2) Check that the gear oil level is within the specified range
from the bottom end of the filler plug hole.
Standard value (A): 6 mm
(3) If the gear oil level exceeds the standard value, add the
specified gear oil up to the bottom end of the filler plug
hole.
Specified gear oil:
MITSUBISHI GENUINE DIA QUEEN SUPER
HYPOID GEAR OIL (GL-5)
NOTE
10
C or more: #90, less than 10
C: #80
(4) Fit the filler plug and tighten it to the specified torque.
Alignment marks
Filler plug
49 Nm
{5.0 kgf
m}
Gear oil
Upper
limit
Lower
limit

REAR AXLE – On-vehicle Service 27-28
2-2 TORQUE TRANSFER MECHANISM
(1) Remove the filler plug.
(2) Check that the gear oil level is up to the bottom end
of the filler plug hole.
(3) If the gear oil level is lower than the bottom end of the
filler plug hole, add the specified gear oil up to the bottom
end of the filler plug hole.
Specified gear oil:
MITSUBISHI GENUINE DIA QUEEN SUPER AYC
FLUID
(4) Fit the filler plug and tighten it to the specified torque.
3. GEAR OIL CHANGE
3-1 DIFFERENTIAL
(1) Remove the drain plug to discharge the gear oil.
(2) Fit the drain plug and tighten it to the specified torque.
Tightening torque: 49 Nm {5.0 kgf
m}
(3) Remove the filler plug and add the specified gear oil
up to the bottom end of the filler plug hole.
Specified gear oil:
MITSUBISHI GENUINE DIA QUEEN SUPER
HYPOID GEAR OIL (GL-5)
Quantity used: 0.41 ± 0.02 dm
3 {0.41 ± 0.02 }
NOTE
10
C or more: #90, less than 10
C: #80
(4) Fit the filler plug and tighten it to the specified torque.
Filler plug
49 Nm {5.0 kgf
m}
Gear oil
Filler plug
49 Nm
{5.0 kgf
m}
Gear oil
Drain plug

REAR AXLE – On-vehicle Service 27-29
3-2 TORQUE TRANSFER MECHANISM
(1) Remove the drain plug to discharge the gear oil.
(2) Fit the drain plug and tighten it to the specified torque.
(3) Remove the filler plug and add the specified gear oil
up to the bottom end of the filler plug hole.
Specified gear oil:
MITSUBISHI GENUINE DIA QUEEN SUPER AYC
FLUID
Quantity used: 0.70
0
0.05dm3{0.700
0.05}
(4) Fit the filler plug and tighten it to the specified torque.
4. FLUID LEVEL CHECK
(1) Remove the maintenance lid located in the luggage
compartment.
(2) If the vehicle has been run, leave it for 5 min. or more
in an ordinary temperature (10
C to 30
C) to allow the
accumulator internal pressure to drop.
NOTE
If the ambient temperature is less than 10
C or less,
allow more time to leave the vehicle to stand idle.
(3) Check that the fluid level in the oil reservoir is in the
range between MAX and MIN.
(4) If the fluid level is lower than MIN, add the specified
fluid.
Specified fluid: MITSUBISHI DIA QUEEN ATF-SPII
(5) Reinstall the maintenance lid.
5. BLEEDING
(1) Lift up the vehicle.
(2) Remove the cap of the left bleeder screw on the torque
transfer differential and connect a vinyl hose.
(3) Gradually turn the steering wheel clockwise from the
straight-ahead position. At this time, loosen the left bleeder
screw and check that fluid is discharged with air.
(4) After air has been completely discharged, tighten the
bleeder screw.
Caution
While the system is being bled of air, add fluid as
necessary to ensure that it is left in the oil reservoir
during the entire procedure.
(5) Repeat steps (3) and (4) two to three times until no air
bubbles are recognized in the fluid that comes out. Then,
tighten the bleeder screw to the specified torque.
Tightening torque: 9 Nm {0.9 kgf
m}
(6) Perform steps (2) through (5) for the right bleeder screw.
Note, however, that the steering wheel should be turned
counterclockwise.
Filler plug
49 Nm {5.0 kgf
m}
Gear oil
Drain plug
49 Nm
{5.0 kgf
m}
Bleeder
screws Vinyl hose

REAR AXLE – On-vehicle Service 27-30
(7) After the system has been completely bled of air, check
for the fluid level.
Caution
If the system is not completely bled of air, the hydraulic
unit could generate noise, degrading pump durability.
6. DIFFERENTIAL CARRIER OIL SEAL
REPLACEMENT
6-1 DIFFERENTIAL
(1) Remove the drive shaft. (Refer to p. 27-36.)
(2) Remove the oil seal from the differential carrier.
(3) Using the special tool, drive a new oil seal all the way
into position.
(4) Coat the oil seal lips and the drive shaft surface in contact
with the oil seal with multi-purpose grease.
(5) Replace the drive shaft circlip with a new one and mount
the drive shaft to the differential carrier. (Refer to P.27-36.)
(6) Check for correct wheel alignment. (Refer to GROUP
34 – On-vehicle Service.)
6-2 TORQUE TRANSFER MECHANISM
(1) Remove the drive shaft. (Refer to p. 27-36.)
(2) Remove the oil seal from the differential carrier.
(3) Using the special tool, drive a new oil seal all the way
into position.
(4) Coat the oil seal lips and the drive shaft surface in contact
with the oil seal with the specified grease.
Specified grease: Vaseline
(5) Replace the drive shaft circlip with a new one and mount
the drive shaft to the differential carrier. (Refer to P.27-36.)
(6) Check for correct wheel alignment. (Refer to GROUP
34 – On-vehicle Service.)MB990938
MB991115
MD998829
MD998812
MD998813