Page 961 of 1449

REAR AXLE -Troubleshooting 27B-15
INSPECTION PROCEDURE 6
Rear tires are noisy during low-speed cornering.
Vehicle skews.
Probable cause
The hydraulic unit or torque transfer differential is probably defective.DDefective hydraulic unit
DDefective torque transfer differential
NOTE
This symptom is limited only when the diagnosis code is correct.
NG
Replace the hydraulic unit. (Refer to
P.27B-61.)
NG
Add fluid. (Refer to P.27B-19.)
OKRepair
Check the trouble symptom.NO
Replace the torque transfer differential.
OK
Is foreign matter trapped in the hydrau-
lic line?YES
Repair
Check the fluid level.
(Refer to P.27B-19.)Check the hydraulic pressure line for
leak.
OK
Check hydraulic pressure.
(Refer to P.27-21.)NGBleed the system of air.
(Refer to P.27-19.)
Check the AYC for operation.
(Refer to P.27B-20.)Check the trouble symptom. OK
NG
NGNG
INSPECTION PROCEDURE 7
Noise is produced from the torque transfer differential
during turning
Probable cause
The torque transfer differential is probably defective.DDefective torque transfer differential
NOTE
This symptom is limited only when the diagnosis code is correct.
NG
Replace the gear oil of the torque transfer differential. (Refer to
P.27B-17.)
Replace the gear oil of the torque transfer differential. (Refer to
P.27B-17.)Normal
Replace the gear oil of the torque transfer differential. (Refer to
P.27B-17.)
Replace the torque transfer differential.
Check the trouble symptom.
OKNG
NG
MUT-IIActuator test
DNo. 06 Clutch operation check (left side) 5 times
DNo. 07 Clutch operation check (right side) 5 times
DSteering wheel on neutral position
DDrive straight in 20 km/h or less
MUT-IIActuator test
DNo. 06 Clutch operation check (left side) 5 times
DNo. 07 Clutch operation check (right side) 5 times
DSteering wheel on neutral position
DDrive straight in 20 km/h or less
Check the trouble symptom.
Normal
Page 962 of 1449

REAR AXLE -On-vehicle Service27B-16
DATA LIST REFERENCE TABLE
For check, refer to GROUP 22.
ACTUATOR TEST REFERENCE TABLE
For check, refer to GROUP 22.
CHECK AT 4WD-ECU TERMINALS
For check, refer to GROUP 22.
ON-VEHICLE SERVICE
REAR AXLE TOTAL BACKLASH CHECK
1. Park the vehicle on a flat, level surface.
2. Move the transmission control lever to the neutral position.
Apply the parking brake. Raise the vehicle on a jack.
3. Turn the companion flange clockwise as far as it will go.
Make the mating mark on the dust cover of the companion
flange and on the differential carrier.
4. Turn the companion flange anti-clockwise as far as it
will go, and measure the amount of distance the mating
marks moved.
Limit: 6 mm
5. If the backlash exceeds the limit value, replace the
differential carrier assembly.
GEAR OIL LEVEL CHECK
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.
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:
Hypoid gear oil
MITSUBISHI Genuine Gear Oil Part No. 8149630
EX, CASTROL HYPOY LS (GL-5, SAE 90),
SHELL-LSD (GL-5, SAE 80W - 90) or equivalent
4. Fit the filler plug and tighten it to the specified torque.
Tightening torque: 49±9 N·m
Mating marks
Upper
limit
Lower
limit
Gear oil
8mm
Page 963 of 1449

REAR AXLE -On-vehicle Service27B-17
Differential part
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.
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:
Hypoid gear oil API classification GL-5 or higher
SAE viscosity Number 90, 80W
NOTE
10_C or more: SAE90, less than 10_C: SAE80W
4. Fit the filler plug and tighten it to the specified torque.
Tightening torque: 49±9 N·m
Torque transfer mechanism part
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.
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: ATF-SP III
4. Fit the filler plug and tighten it to the specified torque.
Tightening torque: 49±9 N·m
GEAR OIL CHANGE
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±9 N·m
3. Remove the filler plug and add the specified gear oil
up to the bottom end of the filler plug hole.
Filler plug
Upper limit
Lower limitGear oil
6mm
Filler plug
Upper limit
Lower limitGear oil
6mm
Page 964 of 1449

REAR AXLE -On-vehicle ServiceREAR AXLE -On-vehicle Service27B-18
Specified gear oil:
Hypoid gear oil
MITSUBISHI Genuine Gear Oil Part No. 8149630
EX, CASTROL HYPOY LS (GL-5, SAE 90),
SHELL-LSD (GL-5, SAE 80W - 90) or equivalent
Quantity: 0.55 L
4. Fit the filler plug and tighten it to the specified torque.
Tightening torque: 49±9 N·m
Differential part
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±9 N·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:
Hypoid gear oil API classification GL-5 or higher
SAE viscosity Number 90, 80W
Quantity: 0.55±0.02 L
NOTE
10_C or more: SAE90, less than 10_C: SAE80W
4. Fit the filler plug and tighten it to the specified torque.
Tightening torque: 49±9 N·m
Torque transfer mechanism part
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±9 N·m
3. Remove the filler plug.
4. Using the oil suction gun (general service tool), between
the body and differential support arm, apply the specified
gear oil up to the under of the filler plug hall.
Specified gear oil: ATF-SP III
Quantity: 0.65 - 0.7 L
5. Fit the filler plug and tighten it to the specified torque.
Tightening torque: 49±9 N·m
Gear oil
Filler plug
Drain plug
Upper limit
Lower limitGear oil
6mm
Filler plug
Drain plug
Oil suction gun
(general service tool)
Page 965 of 1449

REAR AXLE -On-vehicle Service27B-19
FLUID LEVEL CHECK
1. Remove the maintenance lid located in the luggage
compartment.
2.
If the vehicle has been run, leave it for 90 min. or more
in an ordinary temperature (10_C–30_C) to allow the
accumulator internal pressure to drop.
NOTE
If the ambient temperature is 10_C or less, allow more
time to leave the vehicle to stand idle.
Set MUT-IIto 16 pin diagnostic connector. Turn the ignition
switch to the ON position, operate MUT-II, drive the
hydraulic unit (item No.03) forcibly, release the pressure in
the accumulator.
Caution
Turn the ignition switch to the LOCK (OFF) position
before connecting or disconnecting the MUT-II.
NOTE
(1) To drive (oil level check mode) forcibly, turn the
directional valve of the hydraulic unit 20 turns from
side to side, release the differential automatically.
Drive can also be cleared forcibly using the Clear
key of MUT-II.
(2) If the function has been stopped by fail safe, the
hydraulic unit can not be cleared forcibly.
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: ATF-SP III
5. Reinstall the maintenance lid.
BLEEDING
1. Lift up the vehicle.
2. Set the MUT-IIto the 16-pin diagnosis connector.
Caution
Turn the ignition switch to the LOCK (OFF) position
before connecting or disconnecting the MUT-II.
3. Turn the ignition switch to the ON position.
4. Set the steering wheel in the straight-ahead position.
5. Operating the MUT-II, drive the hydraulic unit (item No.02)
forcibly.
NOTE
(1) Drive the bleeding mode forcibly for 5 minutes, release
the operation automatically. Drive can also be cleared
forcibly using the Clear key of MUT-II.
(2) If the function has been stopped by fail safe, the
hydraulic unit cannot be cleared forcibly.
Page 966 of 1449

REAR AXLE -On-vehicle Service27B-20
6. Remove the cap of the left bleeder screw on the torque
transfer differential and connect a vinyl hose.
7. 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.
8. After air has been completely discharged, tighten bleeder
screw and turn the steering wheel in the straight-ahead
position.
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.
9. Repeat steps 6 and 7 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±1 N·m
10. Perform steps 5 through 8 for the right bleeder screw.
Note, however, that the steering wheel should be turned
conterclockwise.
11. When removing the hydraulic unit, bleed the fluid line
in ACD side. (Refer to GROUP 22 – On-vehicle Service.)
12. After the system has been completely bled of air, check
for the fluid level. (Refer to P. 27B-19.)
Caution
If the system is not completely bled of air, the hydraulic
unit could generate noise, degrading pump durability.
AYC OPERATION CHECK
1. Lift up the vehicles.
2. Set the MUT-IIto the 16-pin diagnosis connector.
Caution
Turn the ignition switch to the LOCK (OFF) position
before connecting or disconnecting the MUT-II.
3. Start the engine.
4. Set the gear to the 2nd gear or above, operate MUT-II,
and check from the service data (Item No.09) that the
wheel speed is within 10 km/h to 20 km/h.
NOTE
(1) Set the steering wheel to the neutral position.
(2) When turning the steering wheel, AYC operates
continually (operation sound from the torque transfer
differential), but it is not system fault. In this case,
set the steering wheel to the neutral position, and
perform the following operations in order to stop the
ACD.
DRelease the clutch.
DSet the gear to ”Neutral”.
DStop the engine.
Bleeder
screw
Vinyl hose
Page 967 of 1449

REAR AXLE -On-vehicle Service27B-21
5. Operate the MUT-II, drive the torque transfer differential
(item No.06 and 07) forcibly.
NOTE
(1) Drive the clutch operating mode forcibly for 1 minutes,
release the operation automatically. Drive can also
be cleared forcibly using the Clear key of MUT-II.
(2) If the hydraulic unit function has been stopped by
fail-safe, the torque transfer differential cannot be
forcibly driven.
6. Operating the MUT-II, by service data (item no.07 and 08),
check the condition of the wheel speed below.
The left rear wheel is faster 2km/h than right rear wheel.
The right rear wheel is faster 2km/h than left rear wheel.
NOTE
If the above are not satisfied, check the oil pressure as
the system may be faulty.
OIL PRESSURE CHECK
1. Lift up the vehicle.
2. Set the MUT-IIto the 16-pin diagnosis connector.
Caution
Turn the ignition switch to the LOCK (OFF) position
before connecting or disconnecting the MUT-II.
3. Turn the ignition switch to ON.
4. Disconnect the hydraulic unit and the hydraulic unit hose
assembly, connect the special tool to L port, put the lid
to R port or connect the hydraulic unit hose assembly
disconnected from L port to R port.
5. Operating the MUT-II, drive the hydraulic unit forcibly
(item No.02).
NOTE
(1) Drive the operation check mode of the clutch left
side for 1 minutes, release the operation automatically.
Drive can also be cleared forcibly using the Clear
key of MUT-II.
(2) If the function has been stopped by fail safe, the
hydraulic unit cannot be cleared forcibly.
6. Check that the generated oil pressure of the hydraulic
unit satisfies the standard value.
Standard value: 0.9 – 1.1 MPa
Caution
While the oil pressure is checked, add fluid as
necessary to ensure that it is left in the oil reservoir
during the entire procedure.
7. Check the oil pressure of the clutch right side following step
4 through 6. Connect the special tool to R port, put the lid
to L port or hydraulic unit hose assembly disconnected
from R port to L port, use the MUT-IIdrive item No.07
(operation check mode of clutch right side) forcibly.
MD998330
MB991705
Page 968 of 1449

REAR AXLE -On-vehicle Service27B-22
8. If the measured value exceeds the standard value, replace
the hydraulic unit.
9. Connect the hydraulic unit and the hydraulic unit hose
assembly, and connect the torque transfer differential and
hydraulic unit hose assembly, tighten the flare nut in
specified torque.
Tightening torque: 34±5 N·m (Thread is not lubricated)
26±4 N·m (Thread is lubricated)
10. Supply the specified fluid up to the MAX level of the
oil reservoir, and bleed.
Specified fluid: ATF-SP III
Quantity: 1 L
WHEEL BEARING AXIAL PLAY CHECK
1. Remove the brake caliper and brake disc.
2. Check the bearing’s axial play.
Place a dial gauge against the hub surface; then move
the hub in the axial direction and check whether or not
there is axial play.
Limit: 0.05 mm
3. If the axial play exceeds the limit, the castle nut should
be tightened to the specified torque 225±25 N·m and
check the axial play again.
4. Replace the rear hub assembly if an adjustment cannot
be made to within the limit.
WHEEL BEARING ROTARY-SLIDING
RESISTANCE CHECK
1. Remove the brake caliper and brake disc.
2. After turning the hub a few times to seat the bearing,
wind a rope around the hub bolt and turn the hub by
pulling at a 90_angle with a spring balance. Measure
to determine whether or not the rotary-sliding resistance
of the rear hub is at the limit value.
Limit: 22 N or less