1998 MITSUBISHI LANCER EVOLUTION IV service

27-1
REAR AXLE
CONTENTS
SERVICE SPECIFICATIONS 2. . . . . . . . . . . . . .
LUBRICANT 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SEALANT 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOLS 3. . . . . . . . . . . . . . . . . . . . . . . .
TROUBLESHOOTING 5. . . . . . . . . . . . .
ON-VEHICLE SERVICE
27. . . . . . . . . . . . . . .
1. Rear Axle Total Backlash Check 27. . . . . . .
2. Gear Oil Level Check 27. . . . . . . . . . . . . . . .
3. Gear Oil Change 28. . . . . . . . . . . . . . . . . . . . .
4. Fluid Level Check 29. . . . . . . . . . . . . . . . . . . .
5. Bleeding 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6. Differential Carrier Oil Seal
Replacement 30. . . . . . . . . . . . . . . . . . . . . . . . .
7. Speed Sensor Output Voltage
Measurement 31.
8. Action When Battery Runs Out 32. . . . . . . .
REAR HUB ASSEMBLY 33. . . . . . . . . . . . . . . .
KNUCKLE 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DRIVE SHAFT 36. . . . . . . . . . . . . . . . . . . . . . . . .
DIFFERENTIAL CARRIER
39.
DIFFERENTIAL CARRIER
41. . . . . . . . . . . . . . . . . . .
TORQUE TRANSFER DIFFERENTIAL
43. . . . . . . . . . . . . . .
LSD CASE ASSEMBLY
46. . . . . . . . . . .
HYDRAULIC UNIT
50. . . . . . . . . . . . . . .
SENSOR RELAY
52. . . . . . . . . . . . . . .
AYC-ECU 53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

REAR AXLE – Service Specifications / Lubricant / Sealant27-2
SERVICE SPECIFICATIONS

ItemsStandard valueLimit
Rear axle total backlash mm–5
Pressure generated by hydraulic unit MPa {kgf/cm2}0 – 1.6 {10.0 – 16.0}–
Wheel bearing axial play mm–0.05
Wheel bearing rotation starting torque Nm {kgf
cm}–1.0 {10.5} or less

ItemsStandard valueLimit
Right-to-left difference in combined thickness of friction plate and fric-
tion disc mm0 – 0.05–
Clearance between spring plate and differential case mm0.06 – 0.25–
LSD differential torque
Nm {kgf
m}
When new clutch plate is installed5 – 19 {0.5 – 1.9}–
Nm {kgf
m}
When existing clutch plate is installed2 – 19 {0.2 – 1.9}–
Distortion of friction plate and friction disc mm–0.08
Difference in thickness between friction plate, friction disc, and spring
plate mm–0.1
LUBRICANT

ItemsSpecified lubricantCapacity
Gear oilTorque
transfer
differential
DifferentialMITSUBISHI GENUINE DIA QUEEN SUPER
HYPOID GEAR OIL (GL-5)0.41 ± 0.02 dm3
{0.41 ± 0.02 }
differentialTorque transfer
mechanismMITSUBISHI GENUINE DIA QUEEN AYC FLUID0.700
0.05dm3
{0.700
0.05}
Hydraulic piping fluidMITSUBISHI GENUINE DIA QUEEN ATF-SPII1 dm3 {1 }
Torque transfer mechanism oil seal lipsVaselineAs required
SEALANT

ItemsSpecified sealant
Torque transfer differential vent plugSemi-drying sealant: THREEBOND 1281B (460 g)
Torque transfer mechanism cover

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

REAR AXLE – On-vehicle Service 27-31
7. SPEED SENSOR OUTPUT VOLTAGE
MEASUREMENT ABS>
(1) Lift up the vehicle and release the parking brake.
(2) Disconnect the AYC-ECU harness connector and take
measurements on the harness side connector.
Caution
Insert the probe from the harness side with the double
lock of the connector unlocked. Inserting it to the
terminal side could result in poor contact.
(3) Turn the wheel to be tested at about 1/2 to one
revolution/sec. and check for the output voltage using
a circuit tester (AC mV range) or oscilloscope.
Terminal nos.
Front LHFront RHRear LHRear RH
7698
20192221
Output voltage:
When circuit tester is used: 70 mV or more
When oscilloscope is used: 200 mVp-p or more
(4) If the output voltage is lower than the above value, it
is probably attributable to the following faults. Check or
replace the speed sensor as necessary.
Excessive clearance between the pole piece and rotor
of the speed sensor
Defective speed sensor
Waveform Check Using Oscilloscope
Check the harness and connector of the speed sensor for
connection. Then, use an oscilloscope to check for output
voltage waveform of each speed sensor as follows.
Start the engine and monitor the sensor by turning the wheel;
for a driving wheel, let it turn by shifting into the 1st gear
and for a driven wheel turn it manually at a constant speed.
NOTE
(1) Waveform may be observed by actually running the
vehicle.
(2) The output voltage is low when the wheel speed remains
low and builds up as the wheel speed increases.
AYC-ECU connector harness side
When turned manually
At idle (5 to 6 km/h)
1st gear

REAR AXLE – On-vehicle Service 27-32
Waveform Observation Points
SymptomProbable causeAction
Waveform amplitude is too small, or no
waveform.Defective speed sensorReplace sensor.
Waveform amplitude varies greatly. (No
problem ifthe smallest amplitude is 100
Excessive axle hub lateral and radial runoutReplace hub.
problem if the smallest amplitude is 100
mV or more)Poor AYC-ECU groundingRepair.
Noise on waveform or disturbed
waveform
Open-circuited sensorReplace sensor.
waveform
Open-circuited harnessRepair harness.
Improperly mounted speed sensorCorrect sensor installation.
Missing or collapsed rotor toothReplace rotor.
Caution
Since the speed sensor cable follows the movement of the front or rear suspension, it may be
open-circuited only when the vehicle is run on rough roads and not on ordinary road. The speed
sensor output voltage waveform should therefore be checked also by rocking the sensor harness
so that driving on rough roads may be simulated.
8. ACTION WHEN BATTERY RUNS OUT
When the engine is started using a booster cable where the
battery has completely run down and you attempt to start
the vehicle without waiting for the battery to recover a certain
charge, the engine can misfire and you just cannot start to
move it. In such cases, charge the battery sufficiently; or,
remove the AYC fusible link from the engine compartment
relay box to make AYC inactive before attempting to start
the vehicle. When the fusible link is removed, the AYC warning
lamp lights up. After the battery has been recharged, fit the
fusible link back again and start the engine to ensure that
the AYC warning lamp is off.AYC fusible link