1998 MITSUBISHI LANCER EVOLUTION IV check oil

REAR AXLE – Troubleshooting 27-18
Code No. 81: AYC relay systemProbable cause
This code is output when the coil circuit of the AYC relay is open- or short-circuited.
Defective AYC relay

Defective harness or connector

Defective AYC-ECU
NG
Check and repair the harness between
AYC relay and body ground.
OK
Check the trouble symptom.
OK
Replace AYC-ECU.
NG
Check the harness between AYC relay
and AYC-ECU.NG
Repair
NG
Check the trouble symptom.
OK
Check the following connectors:
B-96, B-126NG
Repair
OK
Measure at A-126 AYC relay connec-
tor.

Disconnect the connector and
measure at the harness side.

Continuity across 1 and body
ground
OK:ConductingNGCheck the following connector:
A-126NG
Repair
Check the AYC relay.
(Refer to P.27-52.)NGReplace the AYC relay.

REAR AXLE – Troubleshooting 27-19
Code No. 82: Electric pump systemProbable cause
This code is output if the pressure switch is not set to high-pressure position despite
the AYC-ECU’s command to drive the AYC relay for a given period of time.
Low hydraulic oil level

Oil leak

Defective fusible link

Defective AYC relay

Defective harness or connector

Defective AYC motor

Defective accumulator pressure switch

Defective AYC-ECU
OK
Replace AYC-ECU.
Check the harness
between AYC relay and
AYC motor, and between
AYC motor and body
ground.NG
Replace
NG
OK
Check the trouble symptom.
OK
Check the following
connectors:
A-126, B-94, B-27, F-32NG
Repair
OK
Replace AYC-ECU.
NG
Check the harness
between AYC-ECU and
accumulator pressure
switch.NG
Repair
NG
Check and repair the har-
ness between fusible link
no. 10 and AYC relay.
OK
Check the trouble symp-
tom.
OK
Replace the hydraulic unit
for a defective accumula-
tor pressure switch.
NO
Repair the leak.
OK
Check the trouble symptom.
NG
Check the following
connector: A-126NG
Repair
YES
Add hydraulic oil.
Is the hydraulic oil level correct in the reservoir tank?
(Refer to P.27-29.)NOIs there a hydraulic oil leak?
Measure at A-126 AYC relay connector.

Disconnect the connector and measure at the harness side.

Voltage across 5 and body ground
OK: Battery voltage
NG
NO
Can pump be operated?YESMeasure at F-31 accumulator pressure switch connector.

Disconnect the connector and measure at the harness side.

Ignition switch: ON

Voltage across 2 and body ground
OK:Battery voltage
YES
Is diagnosis code no. 81 output?YESCheck the AYC relay system. (Refer to P.27-18.)
NG
Check the following
connectors: B-95, B-94,
D-06, F-30, F-31NG
Repair
OK

Check AYC relay for
continuity.
(Refer to P.27-52.)

Check AYC motor for
operation.NG
Repair

REAR AXLE – Troubleshooting 27-22
INSPECTION PROCEDURE 2
AYC warning lamp remains lit up after the engine has
started.
Probable cause
The AYC warning lamp ON circuit is probably short-circuited.
Defective combination meter

Defective harness (short-circuit)

Defective AYC-ECU
NOTE
This symptom is limited only when AYC-ECU power supply is in normal condition and the diagnosis
code is correct.
OK
Replace combination meter.
NO
Check the harness between AYC
warning lamp and AYC-ECU.NG
Repair
Does the AYC warning lamp goes out
when the B-96 AYC-ECU connector
is disconnected?YESReplace AYC-ECU.
INSPECTION PROCEDURE 3
AYC is inoperative.
Unable to start or accelerate on slippery road surfaces.
Probable cause
The hydraulic oil level is probably low, there is an oil leak, the hydraulic unit is defective,
or the torque transfer differential is defective.
Low hydraulic oil level

Oil leak

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
OK
Check the AYC for operation.OKCheck the AYC fluid.
NG
Add hydraulic oil.
NG
Check hydraulic pressure.NGBleed the system of air.
Check the hydraulic oil level.NGCheck for oil leak.OK
Repair

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 – Drive Shaft27-36
DRIVE SHAFT
REMOVAL AND INSTALLATION
Pre-removal Operation
(1) Gear Oil Draining (Refer to P.27-28.)
(2) Center Exhaust Pipe Removal
(Refer to GROUP 15.)Post-installation Operation
(1) Checking Each Ball Joint Dust Cover for Cracks
and Damages by Pressing Dust Cover with Finger
(2) Center Exhaust Pipe Installation
(Refer to GROUP 15.)
(3) Gear Oil Filling (Refer to P.27-28.)
(4) Parking Brake Lever Stroke Check and Adjustment
(Refer to GROUP 36 – On-vehicle Service.)
(5) Wheel Alignment Check and Adjustment
(Refer to GROUP 34 – On-vehicle Service.)
1
2 3
4
56 7
89 10 11
Unit: Nm {kgf
m}
25 {2.6}
74 – 87 {7.5 – 8.9}
74 – 87
{7.5 – 8.9}*88 {9.0}* 49 – 59 {5.0 – 6.0}
196 – 255 {20.0 – 26.0}
Removal steps
1. Caliper assembly
(Refer to P.27-33.)
2. Brake disc
3. Shoe & lining assembly (Refer to
GROUP 36 – Parking Brake.)
4. Clip
5. Parking brake cable connection
AB6. Drive shaft nut
7. Rear speed sensor coupling

8. Trailing arm coupling
9. Lower arm coupling
10. Toe control arm coupling
BA11. Drive shaftCaution
(1) With the part marked with *, first temporarily
tighten it, then ground the vehicle and tighten
it to specification in unloaded condition.
(2) When removing the drive shaft from, and
reinstalling it to, a vehicle with AYC, use care
not to damage the rotor mounted on the BJ outer
race.