2007 INFINITI QX56 oil

TF-2
FRONT OIL SEAL ...........................................116
Removal and Installation .......................................116
REAR OIL SEAL ..............................................118
Removal and Installation .......................................118
SIDE OIL SEAL ...............................................120
Removal and Installation .......................................120
TRANSFER CONTROL DEVICE .....................121
Removal and Installation .......................................121
AIR BREATHER HOSE ...................................122
Removal and Installation .......................................122
TRANSFER MOTOR ........................................125
Removal and Installation .......................................125
TRANSFER OIL FILTER ..................................126
Removal and Installation .......................................126
TRANSFER ASSEMBLY ..................................128
Removal and Installation .......................................128
Disassembly and Assembly ..................................128
SERVICE DATA AND SPECIFICATIONS
(SDS) ................................................................
166
General Specification ............................................166
Inspection and Adjustment ....................................166

TF-6
< SERVICE INFORMATION >
PREPARATION
PREPARATION
Special Service ToolINFOID:0000000003532510
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Tool number
(Kent-Moore No.)
Tool nameDescription
KV40104000
(—)
Flange wrench• Removing self-lock nut
• Installing self-lock nut
a: 85 mm (3.35 in)
b: 65 mm (2.56 in)
KV381054S0
(J-34286)
Puller• Removing front oil seal
• Removing rear oil seal
• Removing metal bushing
KV38100500
(—)
Drift• Installing front oil seal
a: 80 mm (3.15 in) dia.
b: 60 mm (2.36 in) dia.
ST30720000
(J-25405)
Drift• Installing rear oil seal
• Installing mainshaft front bearing and oil
seal
a: 77 mm (3.03 in) dia.
b: 55.5 mm (2.185 in) dia.
KV40105310
(—)
Drift• Installing dust cover
a: 89 mm (3.50 in) dia.
b: 80.7 mm (3.17 in) dia.
ST22360002
(J-25679-01)
Drift• Installing side oil seal
a: 23 mm (0.91 in) dia.
b: 32 mm (1.26 in) dia.
NT659
ZZA0601D
ZZA0811D
ZZA0811D
ZZA1003D
ZZA1091D

PREPARATION
TF-7
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
ST35300000
(—)
Drift• Removing sun gear assembly and planetary
carrier assembly
• Removing carrier bearing
• Installing metal bushing
a: 59 mm (2.32 in) dia.
b: 45 mm (1.77 in) dia.
ST33200000
(J-26082)
Drift• Removing mainshaft front bearing
• Installing sun gear assembly and planetary
carrier assembly
• Installing mainshaft front bearing and oil
seal
a: 74.5 mm (2.933 in) dia.
b: 62.5 mm (2.461 in) dia.
ST30031000
(—)
Puller• Removing carrier bearing
• Removing front drive shaft front bearing
• Removing front drive shaft rear bearing
a: 90 mm (3.54 in) dia.
b: 50 mm (1.97 in) dia.
ST33710000
(—)
Drift• Removing needle bearing
• Removing metal bushing
a: 24 mm (0.94 in) dia.
b: 89 mm (3.5 in)
c: 30 mm (1.18 in) dia.
ST35325000
(—)
Drift bar• Removing metal bushing
a: 215 mm (8.46 in)
b: 25 mm (0.98 in) dia.
c: M12 × 1.5P
ST33052000
(—)
Adapter• Removing front drive shaft front bearing
• Removing front drive shaft rear bearing
• Installing mainshaft
a: 28 mm (1.10 in) dia.
b: 22 mm (0.87 in) dia.
ST22452000
(J-34335)
Drift• Removing press flange snap ring
• Installing press flange snap ring
a: 45 mm (1.77 in) dia.
b: 36 mm (1.42 in) dia.
c: 400 mm (15.76 in) dia. Tool number
(Kent-Moore No.)
Tool nameDescription
NT073
NT661
NT411
ZZA1057D
NT663
NT431
NT117

TF-10
< SERVICE INFORMATION >
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
NVH Troubleshooting ChartINFOID:0000000003532512
Use the chart below to help you find the cause of the symptom. The numbers indicate the order of the inspec-
tion. If necessary, repair or replace these parts.
Reference page
TF-11TF-128TF-128TF-128TF-128
SUSPECTED PARTS
(Possible cause)
TRANSFER FLUID (Level low)
TRANSFER FLUID (Wrong)
TRANSFER FLUID (Level too high)
LIQUID GASKET (Damaged)
O-RING (Worn or damaged)
OIL SEAL (Worn or damaged)
SHIFT FORK (Worn or damaged)
GEAR (Worn or damaged)
BEARING (Worn or damaged)
SymptomNoise 1 2 3 3
Transfer fluid leakage 31222
Hard to shift or will not shift 1 1 2

ALL-MODE 4WD SYSTEM
TF-13
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
POWER TRANSFER FLOW
1. Center case 2. Chain 3. Multiple disc clutch
4. Rear case 5. Mainshaft 6. Clutch hub assembly
7. Sub oil pump 8. Transfer motor 9. Control valve
10. Front drive shaft 11. Drain plug 12. 2-4 sleeve
13. Sun gear assembly 14. L-H sleeve 15. Planetary carrier assembly
16. Internal gear 17. Front case
LDIA0053E

TF-16
< SERVICE INFORMATION >
ALL-MODE 4WD SYSTEM
Hydraulic Control Circuits
TRANSFER MOTOR
• The transfer motor drives the sub-oil pump to provide proper lubrication and oil pressure control when the
vehicle is at standstill, during low-speed operations or is being driven in reverse.
• The main oil pump is operated by the driving force of the mainshaft. In other words, sufficient oil pressure
buildup does not occur when the vehicle is at standstill or during low-speed operations. While the vehicle is
being driven in reverse, the main oil pump rotates in the reverse direction. Therefore the main oil pump does
not discharge oil pressure. During any of the above vehicle operations, the transfer motor drives the sub-oil
pump to compensate for insufficient oil pressure.
• The transfer motor operates as follows.
- The motor relay turns OFF in the 2WD mode.
- The motor relay operates as described in the table below in modes other than the 2WD mode.
Transfer Motor Relay Operation
LDIA0055E
WDIA0163E
4WD shift switch A/T selector lever positionVehicle speed
(VSS)Accelerator pedal positionMotor relay drive
command
2WD — — — OFF

ALL-MODE 4WD SYSTEM
TF-17
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
*: After 2.5 seconds have elapsed.
• 4WD shift switch, PNP switch, Neutral-4LO switch, vehicle speed sensor and throttle position sensor are
used in conjunction with the transfer motor.
WAIT DETECTION SWITCH
• The wait detection switch operates when there is “circulating” torque produced in the propeller shaft (L→H)
or when there is a phase difference between 2-4 sleeve and clutch drum (H→L). After the release of the “cir-
culating” torque, the wait detection switch helps provide the 4WD lock gear (clutch drum) shifts. A difference
may occur between the operation of the 4WD shift switch and actual drive mode. At this point, the wait
detection switch senses an actual drive mode.
• The wait detection switch operates as follows.
- 4WD lock gear (clutch drum) locked: ON
- 4WD lock gear (clutch drum) released: OFF
• The wait detection switch senses an actual drive mode and the 4WD shift indicator lamp indicates the vehi-
cle drive mode.
NEUTRAL-4LO SWITCH
The neutral-4LO switch detects that transfer gear is in neutral or 4LO (or shifting from neutral to 4LO) condi-
tion by L-H shift fork position.
AT P S W I T C H
ATP switch detects if transfer gear is in a neutral condition by L-H shift fork position.
NOTE:
Transfer gear may be in a neutral condition in 4H-4LO.
2-4WD SHIFT SOLENOID VALVE
The 2-4WD shift solenoid valve operates to apply oil pressure to the wet-multiplate clutch, depending on the
drive mode. The driving force is transmitted to the front wheels through the clutch so the vehicle is set in the
4WD mode. Setting the vehicle in the 2WD mode requires no pressure buildup. In other words, pressure force
applied to the wet-multiplate clutch becomes zero.
CLUTCH PRESSURE SOLENOID VALVE
The clutch pressure solenoid valve distributes torque (front and rear) in AUTO mode.
4H (LOCK) and 4LO“N” position 0 — ON
“P” position 00 - 0.07/8 OFF*
0.07/8 - 1/8 HOLD
1/8 - MAX ON
Other than “R” position0 < VSS ≤ 50 km/h (31 MPH)
— ON
50 km/h (31 MPH) < VSS < 55
km/h (34 MPH) HOLD
55 km/h (34 MPH) ≤ VSS OFF
“R” position — — ON
“R” position — — ON
AUTO“P” or “N” position00 - 0.07/8 OFF*
0.07/8 - 1/8 HOLD
1/8 - MAX ON
0 < VSS ≤ 50 km/h (31 MPH)
— ON
50 km/h (31 MPH) < VSS < 55
km/h (34 MPH) HOLD
55 km/h (34 MPH) ≤ VSS OFF
Other than “R”, "P" and "N"
position0 < VSS ≤ 50 km/h (31 MPH)
— ON
50 km/h (31 MPH) < VSS < 55
km/h (34 MPH) HOLD
55 km/h (34 MPH) ≤ VSS OFF 4WD shift switch A/T selector lever positionVehicle speed
(VSS)Accelerator pedal positionMotor relay drive
command

TF-18
< SERVICE INFORMATION >
ALL-MODE 4WD SYSTEM
LINE PRESSURE SWITCH
• With the transfer system design, control of the oil pressure provides the transmission of drive torque to the
front wheels. The main pressure to control the oil pressure is referred to as the line pressure.
• The line pressure switch determines whether or not adequate line pressure has built up under different oper-
ating conditions.
• The line pressure switch turns ON when line pressure is produced.
• The line pressure switch senses line pressure abnormalities and turns the 4WD warning lamp ON.
CLUTCH PRESSURE SWITCH
• The clutch pressure switch determines whether or not adequate clutch pressure has built up under different
operating conditions.
• The clutch pressure switch turns ON when clutch pressure is produced.
• The clutch pressure switch senses clutch pressure abnormalities and turns the 4WD warning lamp ON.
TRANSFER FLUID TEMPERATURE SENSOR
The transfer temperature sensor detects the transfer fluid temperature and sends a signal to the transfer con-
trol unit.
TRANSFER CONTROL UNIT
• Transfer control unit controls transfer control device by input signals of each sensor and each switch.
• Self-diagnosis can be done.
TRANSFER CONTROL DEVICE
The transfer control device changes the state of transfer assembly between 2WD, AUTO, 4H⇔4LO with the
2WD, AUTO, 4H and 4LO signals of 4WD shift switch.
NOTE:
• To shift between 4H⇔4LO, stop the vehicle, depress the brake pedal and shift the transmission selector to
the "N" position. Depress and turn the 4WD shift switch. The shift switch will not shift to the desired mode if
the transmission is not in "N" or the vehicle is moving. The 4LO indicator lamp will be lit when the 4LO is
engaged.
• Actuator motor and actuator position switch are integrated.
4WD SHIFT SWITCH AND INDICATOR LAMP
4WD Shift Switch
The 4WD shift switch allows selection from 2WD, AUTO, 4H or 4LO.
4WD Shift Indicator Lamp
• Displays driving conditions selected by 4WD shift switch with 2WD, AUTO and 4H indicators while engine is
running. (When 4WD warning lamp is turned on, all 4WD shift indicator lamps are turned off.)
• Turns ON for approximately 1 second when ignition switch is turned ON, for purpose of lamp check.
4LO Indicator Lamp
• Displays 4LO condition while engine is running. 4LO indicator lamp flashes if transfer gear does not shift
completely under 2WD, AUTO, 4H⇔4LO. (When 4WD warning lamp is turned on, 4LO indicator lamp is
turned off.)
• Turns ON for approximately 1 second when ignition switch is turned ON, for purpose of lamp check.
4WD WARNING LAMP
Turns ON or FLASH when there is a malfunction in 4WD system.
Also turns ON when ignition switch is turned ON, for purpose of lamp check. Turns OFF for approximately 1
second after the engine starts if system is normal.
4WD Warning Lamp Indication
Condition Content 4WD warning lamp
During self-diagnosis Indicates the malfunction position by number of flickers. Flickers at malfunction mode.
Lamp check*Checks the lamp by turning ON during engine starting. After
engine starts, it turns OFF if there are no malfunctions.ON
Malfunction in 4WD system*Turns ON to indicate malfunction. When ignition switch is
turned to “OFF” or the malfunction is corrected, it turns OFF.ON
When vehicle is driven with different
diameters of front and rear tiresFlickers once every 2 seconds.
Turns OFF when ignition switch is “OFF”.Flickers once every 2 sec-
onds.