YH4
GRAND
VITARA
1. Speed sensor assembly
2. Transfer
7D-4 TRANSFER
SPEEDOMETER DRIVEN GEAR
REMOVAL
1) Lift up vehicle horizontally or rear up.
2) Disconnect speed sensor coupler at transfer case.
3) Remove bolt and take off speed sensor from transfer.
INSTALLATION
1) Make sure that O-ring and speed sensor have not been dam-
aged.
2) Inspect speedometer driven gear for abnormal wear of gear
teeth or bend of shaft portion and replace it if necessary.
3) Make sure its smooth rotation.
4) Install speed sensor assembly to transfer and connect coupler
as it was.
Tightening Torque
(a): 6 N
.m (0.6 kg-m, 4.5 lb-ft)
ENGINE REAR MOUNTING
Refer to ªON-VEHICLE SERVICEº of Section 7A.
YH4
GRAND
VITARA
TRANSFER 7D-7
09940-53111
Bearing installer
UNIT REPAIR
Refer to the same section of UNIT REPAIR MANUAL mentioned in FOREWORD of this manual.
TIGHTENING TORQUE SPECIFICATIONS
FasteningportionTightening torqueFastening ortionN.mkg-mlb-ft
Oil filler / level and drain plugs232.317.0
Engine rear mounting bolts505.036.5
Universal joint flange bolts505.036.5
Speed sensor bolt60.64.5
REQUIRED SERVICE MATERIALS
MATERIALRECOMMENDED
SUZUKI PRODUCTUSE
Lithium greaseSUZUKI SUPER GREASE A
(99000-25010)
Oil seal lips and O-rings.
Splines of propeller shaft.
Select return system.
Shift control lever.
SPECIAL TOOL
YH4
GRAND
VITARA
7E
DIFFERENTIAL (FRONT) 7E-1
The differential assembly using a hypoid bevel pinion
and gear is installed to the front axle.
4WD control system controls drive force to be trans-
mitted to front axles or not. The reduction ratio varies
depending on transmission or engine type.The differential assembly is decisive in that the drive
power is concentrated there. Therefore, use of genu-
ine parts and specified torque is compulsory. Further,
because of sliding tooth meshing with high pressure
between bevel pinion and gear, it is mandatory to lu-
bricate them by hypoid gear oil.
SECTION 7E
DIFFERENTIAL (FRONT)
CONTENTS
GENERAL DESCRIPTION7E- 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4WD CONTROL SYSTEM7E- 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DIAGNOSIS7E- 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DIAGNOSIS TABLE7E- 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Differential Assembly7E- 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4WD Control System Diagnostic Flow Table 7E- 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4WD CONTROL CIRCUIT INSPECTION 7E- 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ON-VEHICLE SERVICE7E- 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MAINTENANCE SERVICE7E- 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gear Oil Change7E- 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INSPECTION7E-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4WD Control System7E-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Actuator7E-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air Pump Assembly7E-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REMOVAL AND INSTALLATION 7E-13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Differential Mountings7E-13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DISMOUNTING7E-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REMOUNTING7E-16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
UNIT REPAIR7E-17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TIGHTENING TORQUE SPECIFICATIONS7E-17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REQUIRED SERVICE MATERIAL7E-17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIAL TOOLS7E-17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION
YH4
GRAND
VITARA
1. 4WD switch
2. Transfer
3. Blank
4. Blank
5. ECM or PCM
6. Glove box7. Air pump assembly
8. Actuator
9. Axle lock clutch
10. Free axle hub
11. 4WD indicator lamp
7E-2 DIFFERENTIAL (FRONT)
4WD CONTROL SYSTEM
When the 4WD switch is turned ON by shifting the transfer shift lever, ECM (PCM) (G16 and J20 engine models)
or 4WD controller (H25 engine model) actuates (energizes) the air pump assembly. Then positive pressure is sent
from the air pump assembly to the actuator installed to the differential case and causes the axle lock clutch and
the free axle hub in the differential case to be engaged, resulting in the 4WD mode. Only when running in the 4WD
mode, front axles are joined to differential case, and they become free when 2WD mode is used (or when transfer
shift lever is shifted to N position), thereby reducing the power loss.
YH4
GRAND
VITARA
7E-4 DIFFERENTIAL (FRONT)
Components and Functions
ComponentFunction
4WD switch
When the transfer shift lever is shifted to 4L or 4H position, this switch turns ON
and causes the 4WD control system to turn ON, unless it is shifted to N or 2H
within 1 second.
ECM or PCM
When the 4WD switch turns ON [unless it turns OFF within 1 second], this com-
ponent actuates the pump assembly. If the pressure in the air pump assembly
fails to increase higher than the set level even after the pump motor has run more
than 10 seconds, this component stops the motor to protect it.
Air pump assembly
Pump motor
Release valve
Pressure switchThe air pump assembly consists of a pump motor, release valve and a pressure
switch.
Pump motor:
Produces positive pressure which actuates the actuator.
Release valve:
Closes when transfer shift lever is shifted to 4H or 4L so that the positive pressure
is applied to the actuator, and opens when N or 2H to release the pressure to the
atmosphere.
Pressure switch:
Turns ON and OFF depending on the pressure level in the pump assembly
(whether higher or lower than the set pressure level). ECM or PCM detects the
pressure level through this switch.
Differential case assembly
Free axle hub
Axle lock clutch
ActuatorThe free axle hub, axle lock clutch and actuator are installed in the differential
left case. The positive pressure produced in the air pump assembly is applied
to the actuator which then pushes the axle lock clutch to be engaged with the free
axle hub. In this state, the drive force is transmitted to the front axle, resulting in
the 4WD mode.
When the actuator is free from the positive pressure [when it is under the atmo-
spheric pressure], the axle lock clutch is pushed back by the return spring force
and cannot be engaged with the free axle hub, resulting in the 2WD mode.
ª4WDº indicator lampIt lights up when 4WD control system is in the 4WD mode.
YH4
GRAND
VITARA
7E-10 DIFFERENTIAL (FRONT)
1. Plugged hose
2. Adjusting screw
3. Pipe (to air pump assembly)
4. Hose (to differential carrier)
5. Differential housing
4 5
INSPECTION
4WD Control System
1) Install special tool to air hose connecting between air pump as-
sembly and differential (actuator) as shown in figure. Tighten ad-
justing screw of special tool as far as it stops. Close air check
side opening by using fuel hose as blind plug.
Special Tool
(A): 09918-18110
(B): 09367-04002
NOTE:
Use care not to bend any part of hose.
2) Turn ON ignition switch and shift transfer lever from 2H to 4H
range.
3) Check that motor starts running (a sound can be heard) within
1 second and it stops when gauge of special tool indicates speci-
fied pressure value.
Check also for air leakage.
Pressure specification:
30.0 ± 45.0 kPa (0.30 ± 0.45 kg / cm
2, 4.25 ± 6.40 psi)
4) Check that pressure value indicated on gauge of special tool
drops as soon as transfer lever is shifted to 2H position.
5) Start motor by shifting transfer lever to 4H position again. Loos-
en adjusting screw to lower pressure value on gauge. Motor
should start to run again and stop in about 4 seconds.
6) With the adjusting screw of special tool loosened, shift transfer
shift lever to N or 2H position and then 4L or 4H position.
Pump motor should stop about 10 seconds after motor starts to
run.
YH4
GRAND
VITARA
DIFFERENTIAL (FRONT) 7E-11
1. Differential housing
2. Adjusting screw
3. To air compressor
Actuator
1) Disconnect air hose from pump assembly and install special tool
to air hose as shown in figure. Loosen adjusting screw of special
tool.
Special Tool
(A): 09918-18110
2) Connect compressor air hose to special tool.
Blow air and turn adjusting screw to obtain specified pressure.
Specified pressure: 30.0 kPa (0.3 kg / cm
2, 4.25 psi)
CAUTION:
Do not apply a pressure exceeding 200 kPa (2.0 kg / cm
2,
28.4 psi) which may cause damage to diaphragm.
3) With the vehicle lifted so that both of the front wheels are off the
ground, turn one of the front wheels by hand and check the other
wheel, which should act as described below.
When the pressure from compressor is applied to actuator:
The other front wheel should turn in the direction opposite to
the wheel being turned by hand.
When the pressure from compressor is not applied to actuator:
The other front wheel should remain stationary while the wheel
pushed by hand is turning.
If the result is not satisfactory, inspect differential assembly. Re-
fer to ªINSPECTIONº of SECTION 7E in UNIT REPAIR MANU-
AL.
YH4
GRAND
VITARA
7E-12 DIFFERENTIAL (FRONT)
1. Pump assembly
Air Pump Assembly
Removal / Installation
1) Disconnect air hoses and coupler from air pump assembly.
2) Remove pump assembly by removing bolts.
3) Reverse removal procedure for installation.
Tightening Torque
(a): 13 N
.m (1.3 kg-m, 9.5 lb-ft)
Inspection
1) Install special tool, voltmeter and battery to pump assembly as
shown in figure.
2) Tighten adjusting screw of special tool as far as it stops and
close its air check side opening by using fuel hose as blind plug.
Special Tool
(A): 09918-18110
3) Check that motor starts to run (a sound can be heard) when bat-
tery is connected and it stops when specified pressure is ob-
tained.
Check also for air leakage.
Specified pressure: 30.0 ± 45.0 kPa
(0.30 ± 0.45 kg / cm
2, 4.25 ± 6.40 psi)
4) Check that value indicated on voltmeter is within specification
shown below.
When motor is running: 0 ± 1 V
When motor has stopped running: 10 ± 14 V
CAUTION:
Do not run motor more than 10 seconds continuously to
prevent motor breakage.