light LEXUS SC400 1991 Service Repair Manual
[x] Cancel search | Manufacturer: LEXUS, Model Year: 1991, Model line: SC400, Model: LEXUS SC400 1991Pages: 4087, PDF Size: 75.75 MB
Page 1243 of 4087

1. Before temporarily installing the new parts,apply body seater to the wheel arch.
HINT:
1) Apply body sealer about 5 mm (0.20 in.) from the flange, avoiding any oozing.
2) Apply sealer evenly, about 3 - 4 mm (0.12 - 0.16 in.) in diameter.
3) For other sealing points, refer to section AR.
RE 42 BODY PANEL REPLACEMENT-Rear Body Components
INSTALLATION
Butt Weld
Body Sealer
Butt Weld
Body Sealer
about 5 mm
2. Temporarily install the new parts and check thefit of the front door, luggage compartment door
and rear combination light.
3. Apply foamed material to the pillar section.
HINT: For the foamed material application areas, refer to page AP-00.
INSTALLATION DIAGRAM
Describes in detail installation of the new parts involving repair by we\
lding and/or cutting,
but excluding painting.
INSTALLATION GUIDE
Provides additional information to more efficiently help you perform the installation.
SYMBOLS
See page IN-4.
ILLUSTRATION OF WELD POINTS
Weld method and panel position symbols.
See page IN-5.
INTRODUCTIONIN-3
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Page 1246 of 4087

Steering Wheel Pad (Airbag and Inflator)
Junction Block No. 1 Center Airbag
Front Airbag Sensor
Front Airbag Sensor
Warning Light Spiral Cable (in Combination Switch)
HANDLING PRECAUTIONS ON RELATED COMPONENTS
1. SRS AIRBAG
Locations of Airbag Components
This vehicle has an SRS AIRBAG (referred to as the airbag in the remain\
der of this manual).
When handling airbag components (removal, installation or inspection, e\
tc.), always follow the directions
given in the repair manual for the relevant model year to prevent the oc\
currence of accidents and airbag
malfunction.
Also take the following precautions when repairing the body:
Work must be started after 20 seconds or longer from the time the ignitio\
n switch is set to the LOCK
position and the negative (-) terminal cable is disconnected from the \
battery.
(The airbag system is equipped with a back-up power source so that if w\
ork is started within 20 seconds
of disconnecting the negative (-) terminal cable of the battery, the airbag may be deployed.)
When the negative (-) terminal cable is disconnected from the battery, memory of the clock and audio
systems will be cancelled. So before starting work, make a record of the\
contents memorized by each
memory system. Then when work is finished, reset the clock and audio sys\
tems as before.
When the vehicle has tilt and telescopic steering, power seat, and outsi\
de rear view mirror, which are all
equipped with memory function, it is not possible to make a record of th\
e memory contents.
So when the operation is finished, it will be necessary to explain this \
fact to the customer, and request
the customer to adjust the features and reset the memory.
To avoid erasing the memory of each memory system, never use back-up powe\
r supply from outside
the vehicle.
When using electric welding, first disconnect the airbag connector (yel\
low color and 2 pins) under the
steering column near the combination switch connector before starting wo\
rk.
Sensor Assembly
INTRODUCTIONIN-6
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Page 1279 of 4087

(b) Slightly lift the radiator, and disconnect the two oil cooler
hoses (for cooling fan) from the hose clamp on the
radiator fan shrould.
(c) Remove the radiator.
(d) Remove the two lower radiator supports.
10. REMOVE FAN SHROULD FROM RADIATOR Remove the four bolts and fan shrould.
INSTALLATION OF RADIATOR
(See Components on page CO±15)
1. INSTALL FAN SHROULD TO RADIATOR Install the fan shrould with the four bolts.
Torque: 4.9 N Vm (50 kgf Vcm, 43 in. Vlbf)
2. INSTALL RADIATOR
(a) Install the two lower radiator supports to the radiator.
(b) Place the radiator on the body bracket.
(c) Slightly lift the radiator, and connect the two oil coolerhoses (for cooling fan) to the hose clamp on the radiator
fan shrould.
CO±18
±
COOLIING SYSTEM Radiator
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Page 1302 of 4087

9. INSTALL FRONT HOUSING(a) Install a new O±ring to the casing groove.
(b) Align the pin holes of the front housing with the straightpin.
(c) Apply a light coat of fluid on the threads and under the heads of the mounting bolts.
(d) Install the front housing with the five bolts.
Torque: 21 N Vm (210 kgf Vcm, 15 ft Vlbf)
10. INSTALL DRIVE SHAFT PRELOAD
(a) Check that the drive shaft rotates smoothly withoutabnormal noise.
(b) Temporarily install the pulley nut, and check the rotating torque.
Rotating torque:
0.3 N Vm (3.0 kgf Vcm, 2.6 in. Vlbf)
11. INSTALL PUMP PULLEY
(a) Slide the pulley onto the drive shaft.
(b) Measure the clearance between the pulley end anddrive shaft end.
Standard: 1.3±1.7 mm (0.051±0.067 in.)
Minimum: 1.0 mm (0.039 in.)
If the clearance is less than minimum, replace the pulley.
CO±40
±
COOLIING SYSTEM Electronically Controlled Hydraulic
Cooling Fan (Hydraulic Pump)
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Page 1311 of 4087

6. DISCONNECT COOLING FAN INLET PIPE FROM FANSHROULD
Remove the two bolts, brackets and bushings, and discon-
nect the inlet pipe.
7. DISCONNECT COOLING FAN RESERVOIR TANK FROM FAN SHROULD
(a) Disconnect the suction hose from the clamp on the fanshrould.
(b) Remove the four bolts, and disconnect the reservoir tank.
8. REMOVE RADIATOR FAN SHROULD (a) Disconnect the wire clamp (for temperature sensor)from the radiator fan shrould.
(b) Remove the four bolts, and disconnect the fan shrould from the radiator.
(c) Slightly lift the fan shrould, and disconnect the two oil cooler hoses (for cooling fan) from the hose clamp on
the fan shrould.
(d) Remove the fan shrould.
±
COOLIING SYSTEM Electronically Controlled Hydraulic Cooling Fan
(Hydraulic Motor)CO±49
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Page 1313 of 4087

DISASSEMBLY OF HYDRAULIC MOTOR
(See Components on page CO±50)
1. MOUNT MOTOR HOUSING Slightly mount the motor housing in a vise.
NOTICE: Be careful not to damage the motor housing.
2. REMOVE MOTOR COVER (a) Remove the four bolts and motor cover.
(b) Remove the O±ring from the motor housing.
3. REMOVE REAR THRUST WASHER AND DRIVE SHAFT
4. REMOVE DRIVE AND DRIVEN ROTORS
5. REMOVE FRONT THRUST WASHER
INSPECTION OF HYDRAULIC MOTOR
1. INSPECT DRIVE AND DRIVEN ROTORS (a) Install the drive and driven rotor to the motor housingwith the dot mark facing upward.
(b) Using a feeler g auge and precision straight edge,
measure the side clearance between the rotor and
precision straight edge.
Standard side clearance: 0.01±0.04 mm
(0.0004±0.0016 in.)
Maximum side clearance: 0.05 mm (0.0020 in.)
If the clearance is greater than maximum, replace the rotors
as a set. If necessary, replace the motor assembly.
±
COOLIING SYSTEM Electronically Controlled Hydraulic Cooling Fan
(Hydraulic Motor)CO±51
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Page 1316 of 4087

ASSEMBLY OF HYDRAULIC MOTOR
(See Components on page CO±50)
HINT:
w Thoroughly clean all parts to be assembled.
w Before installing the parts, apply new fluid to all sliding
and rotating surfaces.
1. MOUNT MOTOR HOUSING Slightly mount the motor housing in a vise.
NOTICE: Be careful not to damage the motor housing.
2. INSTALL FRONT THRUST WASHER
3. INSTALL DRIVEN AND DRIVE ROTORS Install the d rive and driven rotors with the dot mark facing up-
ward.
4. INSTALL DRIVE SHAFT
5. INSTALL REAR THRUST WASHER
6. INSTALL MOTOR COVER (a) Install a new O±ring to the motor housing groove.
(b) Install the motor cover with the four bolts.
Torque: 28 N Vm (290 kgf Vcm, 21 ft Vlbf)
CO±54±
COOLIING SYSTEM Electronically Controlled Hydraulic Cooling Fan
(Hydraulic Motor)
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Page 1317 of 4087

7. INSTALL DRIVE SHAFT PRELOAD(a) Check that the drive shaft rotates smoothly withoutabnormal noise.
(b) Temporarily install the pulley nut, and check the rotating
torque.
Rotating torque:
0.3 N Vm (3.0 kgf Vcm, 2.6 in. Vlbf)
INSTALLATION OF HYDRAULIC MOTOR
(See Components on page CO±47)
1. INSTALL HYDRAULIC MOTOR TO FAN SHROULD Install the hydraulic motor with the three bolts.
Torque: 4.9 N Vm (50 kgf Vcm, 43 in. Vlbf)
2. INSTALL COOLING FAN TO HYDRAULIC MOTOR
Install the fan with the plate washer bolt.
Tighten the nut by turning it counterclockwise.
Torque: 15 N Vm (150 kgf Vcm, 11 ft Vlbf)
3. INSTALL RADIATOR FAN SHROULD
(a) Place the fan shrould on the radiator.
(b) Slightly lift the fan shrould, and connect the two oil cooler
hoses (for cooling fan) to the hose clamp on the fan
shrould.
(c) Install the fan shrould with the four bolts.
Torque: 4.9 N Vm (50 kgf Vcm, 43 in. Vlbf)
±
COOLIING SYSTEM Electronically Controlled Hydraulic Cooling Fan
(Hydraulic Motor)CO±55
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Page 1380 of 4087

The 1 UZ±FE engine has 8±cylinders in a V±arrangement at a bank an\
gle of 905. From the front of the RH
bank cylinders are numbered 2 ± 4 ± 6 ± 8, and from the front of t\
he LH bank cylinders are 1 ± 3 ± 5 ± 7.
The crankshaft is supported by 5 bearings inside the crankcase. These beari\
ngs are made of a copper and
lead alloy.
The crankshaft is integrated with 8 weights for balance. Oil holes are plac\
ed in the center of the crankshaft
to supply oil to the connecting rods, bearing, pistons and other component\
s.
The ignition order is 1 ± 8 ± 4 ± 3 ± 6 ± 5 ± 7 ± 2. T\
he cylinder head is made of alminum alloy, with a cross
flow type intake and exhaust layout and with pent±roof type combustion chambers. The spark plugs are
located in the center of the combustion chambers.
At the front and rear of the intake manifold, a water passage has been p\
rovided which connects the RH
and LH cylinder heads.
Exhaust and intake valves are equipped with irregular pitch springs made\
of special valve spring carbon
steel which are capable of functioning at all engine speeds.
The RH and LH intake camshaft are driven by a timing belt, and a gear on\
the intake camshaft engages
with a gear on the exhaust camshaft to drive it. The cam journal is supp\
orted at 5 (intake) or 4 (exhaust)
places between the valve lifters of each cylinder and on the front end o\
f the cylinder head. Lubrication of
the cam journals and gears is accomplished by oil being supplied through th\
e oiler port in the center of the
camshaft.
Adjustment of the valve clearance is done by means of an outer shim type\
system, in which valve adjusting
shims are located above the valve lifters. This permits replacement of the sh\
ims without removal of the
camshafts.
Pistons are made of high temperature±resistant aluminum alloy, and a depression is built into the piston
head to prevent interference with the valves.
Piston pins are the full±floating type, with the pins fastened to neither the piston boss nor the connecting
rods. Instead, snap rings are fitted on both ends of the pins, preventing the\
pins from falling out.
The No.1 compression ring is made of steel and the No.2 compression ring\
is made of cast iron. The oil
ring is made of a combination of steel and stainless steel. The outer diamet\
er of each piston ring is slightly
larger than the diameter of the piston and the flexibility of the rings allows them to hug the cylinder walls
when they are mounted on the piston. Compression rings No.1 and No.2 work to\
prevent gas leakage from
the cylinder and the oil ring works to scrape oil off the cylinder walls to prevent it from entering the combus-
tion chambers.
The cylinder block is made of aluminum alloy with a bank of 90 5. Cast iron cylinders are installed inside
the cylinder block. It has 8 cylinders which are approximately twice the le\
ngth of the piston stroke. The top
of each cylinder is closed off by the cylinder head and the lower end of the cylinders becomes the crank-
case, in which the crankshaft is installed. In addition, the cylinder block c\
ontains a water jacket, through
which coolant is pumped to cool the cylinders.
The No.1 and No.2 oil pans are bolted onto the bottom of the cylinder bl\
ock. The No.1 oil pan is made of
aluminum alloy. The No.2 oil pan is an oil reservoir made of pressed steel sheet. An o\
il level sensor is
installed in the No.1 oil pan (If oil level drops below a set level, a warning light\
s up.). And oil pan baffle plate
keeps sufficient oil in the bottom of the No.2 oil pan even when the vehicle is t\
ilted. This dividing plate also
prevents the oil from marking waves when the vehicle is stopped suddenly\
and the oil shifts away from the
oil pump suction pipe.
Plastic region tighten bolts are used for the cylinder head, main bearin\
g cap and connecting rod.
EG±4
±
1UZ±FE ENGINE ENGINE MECHANICAL
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Page 1386 of 4087

EG0B4±0K
ENGINE OIL INSPECTION
1. CHECK OIL QUALITYCheck the oil for deterioration, entry of water, discoloring or
thinning.
If oil quality is visibly poor, replace the oil.
Oil grade:
API grade SG or SH, Energy±Conserving II or ILSAC
multigrade engine oil. Recommended viscosity is as
shown in the illustration, with SAE 5W±30 being the
preferred engine oil.
Drain and refill capacity: w/ Oil filter change
4.8 liters (5.1 US qts, 4.2 lmp. qts)
w/o Oil filter change
4.5 liters (4.8 US qts, 4.0 lmp. qts)
2. CHECK ENGINE OIL LEVELThe oil level should be between the ªLº and ªFº marks on the
dipstick.
If low, check for leakage and add oil up to the ªFº mark.
EG3E2±01
BATTERY INSPECTION
1. CHECK BATTERY ELECTROYTE LEVEL AND VOLTAGE
(a) Check the electrolyte quantity of each cell.If under the lower level, replace the battery (or add distilled
water if possible.). Need to check the charging system.
(b) Measure the battery voltage between the terminals negative (±) and positive (+) of the battery.
Standard voltage:
12.7±12.9 V at 20 5C (68 5F)
HINT:
w Before measuring the voltage, turn the ignition switch
OFF and turn off the electrical systems (headlight,
blower motor, rear defogger etc.) for 60 seconds to
remove the surface charge.
EG±10
±
1UZ±FE ENGINE ENGINE MECHANICAL
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