1999 SUZUKI GRAND VITARA Transfer

YH4
GRAND
VITARA
1. Wood block
2. Dash panel
t: 45 mm / 1.8 in.
H: 200 mm / 8 in.
W: 100 ± 150 mm / 4 ± 6 in.
1. Transmission jack
2. Engine rear mounting member
3. Gear shift lever case
4. Bolt
TRANSFER 7D-5
TRANSFER ASSEMBLY
Dismounting and remounting of transfer and transmission together
as a unit is described in Section 7A for Manual Transmission or 7B1
for Automatic Transmission, but it is also possible to dismount and
remount transfer assembly by itself as described below.
DISMOUNTING
IN ENGINE ROOM
1) Disconnect negative (±) cable from battery.
2) Remove distributor assembly (if equipped).
3) Place wood block between engine and dash panel so that it
serves as stopper when engine, transmission and transfer unit
hangs down as rear mounting member is removed.
CAUTION:
Make sure to use wood block to prevent contact which
may occur between dash panel and CMP sensor case
(G16), CMP sensor (J20) or intake manifold (H25), and fan
and shroud.
IN CABIN
1) Remove console box.
2) Remove shift lever of transmission and transfer.
ON LIFT
1) Drain transfer oil.
2) Remove rear propeller shaft.
3) Remove front propeller shaft.
4) Disconnect exhaust center pipe.
5) Disconnect speed sensor coupler.
6) Place transmission jack and remove mounting member.
7) Lower transmission jack gradually and check to ensure that
wood block serves as stopper between engine and dash panel.
8) Remove bolts for gear shift lever case.
9) Pull off breather hose.

YH4
GRAND
VITARA
1. Bolt
2. Transfer assembly
1. Bolt
2. Engine rear mounting3. Transfer assembly
1. Bolt
2. Transfer assembly
3. Transmission jack
7D-6 TRANSFER
IN CABIN
Remove gear shift lever case and then remove transfer center case
bolt.
ON LIFT
1) Remove transfer mounting (engine rear mounting) by removing
bolts.
2) Apply transmission jack to transfer to support it.
3) Remove couplers for 4WD / 4WD-LOW switches lead.
4) Remove transfer front case bolts.
5) With transfer assembly supported with transmission jack, slide
it rearward and when it is apart from transmission, lower it.
REMOUNTING
For remounting, reverse dismounting procedure described above,
noting following.

Be sure to use specified torque for tightening.

Clamp wiring and breather hose securely.

Clamp shift lever boot securely.

Fill specified gear oil by specified amount.

Connect battery and check for function.

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
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
1. 4WD switch
2. Air pump assembly
3. Pump motor
4. Release valve
5. Pressure switch6. Transfer
7. Front differential
8. Air hose and pipe
9. 4WD indicator lamp
10. To ignition switch
11. ECM or PCM
Operation
(refer to ªComponents and Functionsº)
Power supply
(from ECM or PCM)
DIFFERENTIAL (FRONT) 7E-3
System Circuit and Operation

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
DIFFERENTIAL (FRONT) 7E-5
DIAGNOSIS
DIAGNOSIS TABLE
Differential Assembly
ConditionPossible CauseCorrection
Gear noise
Deteriorated or water mixed lubricant

Inadequate or insufficient lubricant

Maladjusted backlash between bevel
pinion and gear

Improper tooth contact in the mesh between
bevel pinion and gear

Loose bevel gear securing bolts

Damaged side gear(s) or side pinion(s)Repair and replenish
Repair and replenish
Adjust
Adjust or replace
Replace or retighten
Replace
Bearing noise
(Constant noise) Deteriorated or water
mixed lubricant

(Constant noise) Inadequate or insufficient
lubricant

(Noise while coasting) Damaged bearing(s)
of bevel pinion

(Noise while turning) Damaged diff. side
bearing(s) or axle bearing(s)Repair and replenish
Repair and replenish
Replace
Replace
Oil leakage
Worn or damaged oil seal

Excessive oil

Loose differential carrier boltsReplace
Adjust oil level
Replace or retighten
2WD / 4WD
switching error
Defective actuator

Abnormality in 4WD control systemReplace
Inspect referring to ª4WD
CONTROL SYSTEM DIAG-
NOSTIC FLOW TABLEº.
4WD Control System Diagnostic Flow Table
Before performing the trouble diagnosis, check that the transfer and front differential are in good condition and
there is no air leakage from air hoses and the actuator. Refer to ªON-VEHICLE SERVICEº in this section for air
leakage.
[NOTES ON SYSTEM CIRCUIT INSPECTION]

Be sure to read ªPrecautions for Electrical Circuit Serviceº in Section 0A before circuit inspection and observe
what is written there.

For system circuit, refer to the figure of ªGENERAL DESCRIPTIONº in this section.

For terminal arrangement, refer to ª4WD Control Circuit Inspectionº in this section.

YH4
GRAND
VITARA
7E-6 DIFFERENTIAL (FRONT)
STEPACTIONYESNO
1Turn ON ignition switch (but engine at stop) and
check malfunction indicator lamp.
Does lamp light up?Go to step 2.A trouble has
occurred at some
place. Repair it
referring to
MALFUNCTION
INDICATOR LAMP
(ªCHECK ENGINEº
LAMP) CHECK in
DIAGNOSIS of
SECTION 6.
2Check 4WD switch circuit.
Turn ignition switch ON and check that voltage
between terminal C51-2-18 and terminal C51-3-17
(ground) for G16 / J20 (terminal C51-1-11 and terminal
C51-3-26 (ground) for H25) is as follows.

When transfer shift lever is in N or 2H: 10 ± 14 V

When transfer shift lever is in 4L or 4H: 0 ± 1 V
Is the check result satisfactory?Go to step 3.Check 4WD switch
(refer to SECTION
7A), ªB / Orº and ªBº
circuits of 4WD
switch.
If OK, substitute a
known-good ECM
(PCM) and recheck.
3Check power supply.
1) Turn ignition switch ON.
2) Check voltage between C51-2-7 and C51-3-17
(ground) for G16 / J20 (C51-1-15 and C51-3-26
(ground) for H25). The check results should be as
follows.

When transfer shift lever is in N or 2H: 0 ± 1 V

When transfer shift lever is in 4L or 4H: 10 ± 14 V
Is the check result satisfactory?Go to step 4.Check ªRº circuit. If
it is OK, substitute a
known-good ECM
(PCM) and recheck.
4Check air pump assembly circuit.
1) Check for proper connection to air pump
assembly at all terminals.
2) Turn ignition switch ON.
3) Check voltage between C51-2-27 and C51-3-17
(ground) for G16 / J20 (C51-1-18 and C51-3-26
(ground) for H25). The check result should be as
follows.

When transfer shift lever is in 2H or N: 0 ± 1 V

When transfer shift lever is in 4L or 4H
(more than 4 seconds after shifted to 4L or 4H):
10 ± 14 V
Is the check result satisfactory?Go to step 5.Check air pump
assembly referring
to ªON-VEHICLE
SERVICEº, and then
ªPº circuit.
If OK, substitute a
known-good ECM
(PCM) and recheck.
5Check 4WD indicator lamp circuit.
1) Turn ignition switch ON.
2) Check voltage between E61-19 and C51-3-17
(ground) for G16 / J20 (C51-1-7 and C51-3-26
(ground) for H25). The check result should be as
follows.

When transfer shift lever is in 2H or N: 10 ± 14 V

When transfer shift lever is in 4L or 4H: 0 ± 1 V
Is the check result satisfactory?4WD control system
is in good condition.Check ªOr / Bº circuit
(including indicator
lamp and
combination meter).
If OK, substitute a
known-good ECM
(PCM) and recheck.