front axle SUZUKI GRAND VITARA 2003 2.G Service Owner's Guide

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.