low oil pressure INFINITI QX4 2001 Factory Workshop Manual

SLC324B
SLC932A
SLC933A
SLC934AB
OIL PUMP INSPECTIONNBLC0007IInstall oil pump with the groove of the inner rotor facing
the oil pump cover.
Using a feeler gauge, straightedge and micrometers, check the
following clearances:
Unit: mm (in)
Body to outer rotor radial clearance 1 0.114 - 0.200 (0.0045 - 0.0079)
Inner rotor to outer gear tip clearance
2Below 0.18 (0.0071)
Body to inner rotor axial clearance 3 0.030 - 0.070 (0.0012 - 0.0028)
Body to outer rotor axial clearance 4 0.050 - 0.110 (0.0020 - 0.0043)
Inner rotor to brazed portion of hous-
ing clearance 50.045 - 0.091 (0.0018 - 0.0036)
IIf the tip clearance (2) exceeds the limit, replace rotor set.
IIf body to rotor clearances (1, 3, 4, 5) exceed the limit,
replace oil pump body assembly.
SLC251B
REGULATOR VALVE INSPECTIONNBLC00081. Visually inspect components for wear and damage.
2. Check oil pressure regulator valve sliding surface and valve
spring.
3. Coat regulator valve with engine oil. Check that it falls
smoothly into the valve hole by its own weight.
If damaged, replace regulator valve set or oil pump body.
ENGINE LUBRICATION SYSTEM
Oil Pump (Cont'd)
LC-6

IInspect the oil cooler after removing it.
SLC333B
3. Installation is in reverse order of removal.
IWhen installing the oil cooler, align the oil cooler stopper
with the stopper of the oil cooler bracket.
INSPECTIONNBLC0037Oil CoolerNBLC0037S011. Check oil cooler for cracks.
2. Check oil cooler for clogging by blowing through coolant inlet.
If necessary, replace oil cooler assembly.
Oil Pressure Relief ValveNBLC0037S02Inspect oil pressure relief valve for movement, cracks and breaks
by pushing the ball. If replacement is necessary, remove valve by
prying it out with a suitable tool. Install a new valve in place by
tapping it.
Service Data and Specifications (SDS)
OIL PRESSURENBLC0010
Engine speed
rpmApproximate discharge pressure
kPa (kg/cm2, psi)
Idle speed
2,000More than 98 (1.0, 14)
294 (3.0, 43)
REGULATOR VALVENBLC0011Unit: mm (in)
Regulator valve to oil pump cover clearance 0.040 - 0.097 (0.0016 - 0.0038)
OIL PUMPNBLC0012Unit: mm (in)
Body to outer rotor radial clearance 0.114 - 0.200 (0.0045 - 0.0079)
Inner rotor to outer rotor tip clearance Below 0.18 (0.0071)
Body to inner rotor axial clearance 0.030 - 0.070 (0.0012 - 0.0028)
Body to outer rotor axial clearance 0.050 - 0.110 (0.0020 - 0.0043)
Inner rotor to brazed portion of housing clearance 0.045 - 0.091 (0.0018 - 0.0036)
ENGINE LUBRICATION SYSTEM
Oil Cooler (Cont'd)
LC-8

SEM164F
AEM080
Precautions
LIQUID GASKET APPLICATION PROCEDURENBLC00131. Use a scraper to remove all traces of old liquid gasket from
mating surfaces and grooves. Also, completely clean any oil
from these areas.
2. Apply a continuous bead of liquid gasket to mating surfaces.
(Use Genuine RTV silicone sealant Part No. 999MP-A7007
or equivalent.)
IFor oil pan, be sure liquid gasket diameter is 4.0 to 5.0 mm
(0.157 to 0.197 in).
IFor areas except oil pan, be sure liquid gasket diameter is 2.0
to 3.0 mm (0.079 to 0.118 in).
3. Apply liquid gasket around the inner side of bolt holes (unless
otherwise specified).
4. Assembly should be done within 5 minutes after coating.
5. Wait at least 30 minutes before refilling engine oil and engine
coolant.
Preparation
SPECIAL SERVICE TOOLSNBLC0014The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Tool number
(Kent-Moore No.)
Tool nameDescription
WS39930000
(Ð)
Tube pressure
NT052
Pressing the tube of liquid gasket
EG17650301
(J33984-A)
Radiator cap tester
adapter
NT564
Adapting radiator cap tester to radiator filler neck
a: 28 (1.10) dia.
b: 31.4 (1.236) dia.
c: 41.3 (1.626) dia.
Unit: mm (in)
KV99103510
(Ð)
Radiator plate pliers A
NT224
Installing radiator upper and lower tanks
KV99103520
(Ð)
Radiator plate pliers B
NT225
Removing radiator upper and lower tanks
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ENGINE COOLING SYSTEM
Precautions
LC-9

SLC031B
2. Install water pump.
IDo not allow cylinder block to nip O-rings when installing
water pump.
SLC944A
3. Before installing, remove all traces of liquid gasket from mat-
ing surface of water pump cover and chain tensioner cover
using a scraper.
Also remove traces of liquid gasket from mating surface of
front cover.
SLC945AA
4. Apply a continuous bead of liquid gasket to mating surface of
chain tensioner cover and water pump cover.
SLC156B
5. Return the crankshaft pulley to its original position by turning
it 20É forward.
SLC961A
6. Install timing chain tensioner, then remove the stopper pin.
IWhen installing the timing chain tensioner, engine oil
should be applied to the oil hole and tensioner.
IAfter starting engine, let idle for three minutes, then rev
engine up to 3,000 rpm under no load to purge air from the
high-pressure chamber of the chain tensioners. The
engine may produce a rattling noise. This indicates that
air still remains in the chamber and is not a matter of
concern.
7. Reinstall any parts removed in reverse order of removal.
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ENGINE COOLING SYSTEM
Water Pump (Cont'd)
LC-15

SMA632C
SMA631C
Changing Differential Gear OilNBMA00271. Drain oil from drain plug and refill with new gear oil.
2. Check oil level.
Oil grade and viscosity:
See ªRECOMMENDED FLUIDS AND LUBRICATNSº,
MA-11, 12.
Oil capacity:
Front
1.85(3-7/8 US pt, 3-1/4 Imp pt)
Rear
2.8(5-7/8 US pt, 4-7/8 Imp pt)
Filler plug:
Front
: 39 - 59 N´m (4 - 6 kg-m, 29 - 43 ft-lb)
Rear
: 59 - 118 N´m (6 - 12 kg-m, 43 - 87 ft-lb)
Drain plug:
Front
: 59 - 98 N´m (6 - 10 kg-m, 43 - 72 ft-lb)
Rear
: 59 - 118 N´m (6 - 12 kg-m, 43 - 87 ft-lb)
LIMITED-SLIP DIFFERENTIAL GEARNBMA0027S01IUse only approved limited-slip differential gear oil.
ILimited-slip differential identification.
1. Lift both rear wheels off the ground.
2. Turn one rear wheel by hand.
3. If both rear wheels turn in the same direction simultaneously,
vehicle is equipped with limited-slip differential.
Balancing WheelsNBMA0028Adjust wheel balance using the road wheel center.
Wheel balance (Maximum allowable unbalance):
Refer to SDS, MA-29.
SGI991
Tire RotationNBMA0029IAfter rotating the tires, adjust the tire pressure.
IRetighten the wheel nuts after the vehicle has been driven
for 1,000 km (600 miles). (also in cases of a flat tire, etc.)
Wheel nuts:
: 118 - 147 N´m (12 - 15 kg-m, 87 - 108 ft-lb)
CHASSIS AND BODY MAINTENANCE
Changing Differential Gear Oil
MA-24

CAUTION:
Do not hold the steering wheel in a locked position for more
than 15 seconds.
4. If fluid leakage at connectors is noticed, loosen flare nut and
then retighten.
Do not overtighten connector as this can damage O-ring,
washer and connector.
5. Check rack boots for accumulation of power steering fluid.
Bleeding Hydraulic SystemNBST00131. Raise front end of vehicle until wheels are clear of the ground.
2. Add fluid into oil tank to specified level. Then, quickly turn
steering wheel fully to right and left and lightly touch steering
stoppers.
Repeat steering wheel operation until fluid level no longer
decreases.
3. Start engine.
Repeat step 2 above.
IIncomplete air bleeding will cause the following to occur. When
this happens, bleed air again.
a) Air bubbles in reservoir tank
b) Clicking noise in oil pump
c) Excessive buzzing in oil pump
Fluid noise may occur in the valve or oil pump. This is common
when the vehicle is stationary or while turning steering wheel
slowly. This does not affect performance or durability of the system.
SST491B
SST090B
Checking Steering Wheel Turning ForceNBST00141. Park vehicle on a level, dry surface and set parking brake.
2. Start engine.
3. Bring power steering fluid up to adequate operating tempera-
ture. [Make sure temperature of fluid is approximately 60 to
80ÉC (140 to 176ÉF).]
Tires need to be inflated to normal pressure.
4. Check steering wheel turning force when steering wheel has
been turned 360É from the neutral position.
Steering wheel turning force:
39 N (4 kg, 9 lb) or less
5. If steering wheel turning force is out of specification, check
rack sliding force.
a. Disconnect steering column lower joint and knuckle arms from
the gear.
b. Start and run engine at idle to make sure steering fluid has
reached normal operating temperature.
c. Pull tie-rod slowly to move it from neutral position to±11.5 mm
(±0.453 in) at speed of 3.5 mm (0.138 in)/s. Check that rack
sliding force is within specification.
Rack sliding force:
137 - 255 N (14 - 26 kg, 31 - 57 lb)
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ON-VEHICLE SERVICE
Checking Fluid Leakage (Cont'd)
ST-9

LINE PRESSURE SWITCH...........................................83
Diagnostic Procedure ................................................83
ABS OPERATION SIGNAL...........................................86
Diagnostic Procedure ................................................86
DATA ERASE/DISPLAY...............................................88
Diagnostic Procedure ................................................88
SHIFT ACTUATOR........................................................89
Diagnostic Procedure ................................................89
SHIFT ACTUATOR POSITION SWITCH......................92
Diagnostic Procedure ................................................92
SHIFT ACTUATOR CIRCUIT........................................94
Diagnostic Procedure ................................................94
TROUBLE DIAGNOSES FOR SYMPTOMS.................98
Symptom 1. 4WD Shift Indicator Lamp Does Not
Turn ON .....................................................................98
Symptom 2. 4WD Warning Lamp Does Not Turn
ON............................................................................100
Symptom 3. 4WD Shift Indicator Lamp Does Not
Turn OFF .................................................................102
Symptom 4. ATP Warning Lamp Does Not Turn
ON............................................................................102
Symptom 5. 4LO Indicator Lamp Does Not Turn
ON............................................................................104
Symptom 6. 4WD Shift Indicator Lamp Does Not
Indicate²4H²............................................................106
Symptom 7. 4WD Shift Indicator Lamp Repeats
Flickering..................................................................107
Symptom 8. Tight Corner Braking Symptom...........108
Symptom 9. 4WD System Does Not Operate.........109
COMPONENT INSPECTION....................................... 111
4WD Shift Switch ..................................................... 111
2-4WD Shift Solenoid Valve and Transfer Fluid
Temperature Sensor ................................................ 111
4WD Solenoid Valve, Clutch Pressure Switch
and Line Pressure Switch........................................ 111
Front Revolution Sensor .......................................... 112
Transfer Dropping Resistor...................................... 112
ATP Switch, Neutral-4LO Switch and Wait
Detection Switch ...................................................... 112
Transfer Motor ......................................................... 113
Transfer Motor Relay ............................................... 113
Transfer Sub-harness .............................................. 113
FRONT REVOLUTION SENSOR SUB-HARNESS
CONNECTOR
........................................................ 113
TRANSFER SWITCH ASSEMBLY SUB-HARNESS
CONNECTOR
........................................................ 114
TRANSFER TERMINAL CORD ASSEMBLY SUB-
HARNESS CONNECTOR
....................................... 114
Transfer Shift Relay (High & low) ............................ 114
Actuator & Actuator Position Switch ........................ 115
ACTUATOR........................................................... 115
ACTUATOR POSITION SWITCH............................ 115
ON-VEHICLE SERVICE.............................................. 116
Replacing Oil Seal ................................................... 116
FRONT CASE OIL SEAL........................................ 116
SHIFT SHAFT OIL SEAL........................................ 117
REAR OIL SEAL.................................................... 117
Transfer Motor ......................................................... 117
REMOVAL............................................................. 117
INSTALLATION...................................................... 117
Transfer Oil Filter ..................................................... 118
REMOVAL............................................................. 118
INSTALLATION...................................................... 118
REMOVAL AND INSTALLATION............................... 119
Removal ................................................................... 119
Installation ................................................................ 119
OVERHAUL.................................................................120
Transfer Gear Control ..............................................120
Transfer Components ..............................................121
DISASSEMBLY............................................................123
Rear Case................................................................123
DISASSEMBLY......................................................123
Center Case.............................................................123
DISASSEMBLY......................................................123
Front Case ...............................................................133
DISASSEMBLY......................................................133
REPAIR FOR COMPONENT PARTS.........................137
Front Case ...............................................................137
INSPECTION.........................................................137
Center Case.............................................................138
INSPECTION.........................................................138
ASSEMBLY..................................................................141
Front Case ...............................................................141
ASSEMBLY...........................................................141
Center Case.............................................................145
ASSEMBLY...........................................................145
Final Assembly.........................................................153
SERVICE DATA AND SPECIFICATIONS (SDS).......157
General Specifications .............................................157
Inner Gear and Outer Gear .....................................157
SUB-OIL PUMP.....................................................157
MAIN OIL PUMP....................................................157
Control Valve ...........................................................157
VALVE..................................................................157
SPRING................................................................157
Clutch .......................................................................158
DRIVE PLATE.......................................................158
DRIVEN PLATE.....................................................158
RETURN SPRING..................................................158
RETAINING PLATE................................................158
Seal Ring (Mainshaft side) ......................................159
Bearing Race (Thrust needle bearing side) ............159
Snap Ring (Sun gear side) ......................................159
CONTENTS(Cont'd)
TF-2

Description of Electrical PartsNBTF0067TRANSFER MOTORNBTF0067S011. 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.
2. 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.
3. The transfer motor operates as follows:
1) The motor relay turns OFF in the 2WD mode.
2) The motor relay operates as described in the table below in modes other than the 2WD mode.
Table 1
PNP switch ªRº position VFF (Vehicle speed) A/T position Motor relay drive command
ON Ð R ON
OFF0 km/hPositions other than the ªPº or
ªNº positionsON
ЪPº or ªNº position (See Table
2.)Ð
0 < VFF%30 km/h Ð ON
30 < VFF < 35 km/h Ð HOLD
35 km/h%VFF Ð OFF
Table 2
A/T position N-4L SW 4WD modeThrottle position
0 - 0.07/8 0.07/8 - 1/8 1/8 - MAX
NOFFLOCK (4H) ON ON ON
Positions other than
the LOCK position
(2WD or AUTO)See NOTE. HOLD ON
ON Ð See NOTE. HOLD ON
P Ð Ð See NOTE. HOLD ON
NOTE:
OFF (after 2.5 seconds have elapsed.)
4. 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 SWITCHNBTF0067S021. The wait detection switch releases the ªboomingº torque produced in the propeller shaft. After the release
of the ªboomingº torque, the wait detection switch helps provide the 4WD lock gear (clutch drum) shifts.
A difference may occur between the operation (ª4LOº to ª4Hº shift only) of the 4WD shift switch and actual
drive mode. At this point, the wait detection switch senses an actual drive mode.
2. The wait detection switch operates as follows:
4WD lock gear (clutch drum) locked: ON
4WD lock gear (clutch drum) released: OFF
3. The wait detection switch senses an actual drive mode and the 4WD shift indicator lamp indicates the
vehicle drive mode.
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ALL-MODE 4WD SYSTEM
Description of Electrical Parts
TF-15

Symptom 9. 4WD System Does Not Operate=NBTF0037SYMPTOM: The vehicle cannot be put into 4WD mode.
(Hydraulic system failure)
1 CHECK INPUT SIGNAL
With CONSULT-II
1. Select ªECU INPUT SIGNALSº in Data Monitor.
2. Read out the ON/OFF status of ªCLUTCH PRES SWº.
SMT977D
Without CONSULT-II
Check voltage between transfer control unit harness connector terminal 34 and body ground.
Refer to ªTRANSFER CONTROL UNIT INSPECTION TABLEº, ªTROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONº,
TF-55.
OK or NG
OK©1. Check transfer fluid level.
2. Disassemble transfer unit and check the following.
ITransfer motor
IMain oil pump assembly
ISub-oil pump assembly
IOil strainer
IControl valve assembly
I2-4WD shift solenoid valve
IOil filter element
ILip seal
IStrainer O-ring
IMain oil pump drive gear
ISeal ring
ID-ring
IClutch piston
IClutch assembly
NG©GO TO 2.
2 CHECK CLUTCH PRESSURE CIRCUIT
Check clutch pressure switch circuit.
Refer to ªDiagnostic Procedureº, ªCLUTCH PRESSURE SWITCHº, TF-80.
OK or NG
OK©GO TO 3.
NG©Check, repair or replace faulty parts.
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TROUBLE DIAGNOSES FOR SYMPTOMS
Symptom 9. 4WD System Does Not Operate
TF-109