LEXUS SC400 1991 Service Repair Manual

Proper and Efficient Work ProceduresREMOVAL
NUMBER OF SPOT WELDS AND PANEL POSITIONS
The number of spot welds and the panel positions to be
removed are shown for your reference.
HINT: See ºSymbols º on page IN-4,5 .
PRE-REMOV AL MEASURING
Before removal or cutting
operations, take measurements
in accordance with the dimen-
sion diagram. Always use a
puller to straighten a damaged
body or frame.
REMOVAL of ADJACENT COMPONENTS
When removing adjacent components, ap-
ply protective tape to the surrounding body
and your tools to prevent damage.
HINT: See ºHandling Precautions on Related Components º on page IN-9.
PRECAUTIONS FOR DRILLING OR
CUTTING
Check behind any area to be drilled or
cut to insure that there are no hoses,
wires, etc., that may be damaged.
HINT: See ºHandling Precautions on
Related Components º on page IN-9.
CUTTING AREA
Always cut in a straight
line and avoid reinforced
areas.
Cutting Okay
Corners
Reinforcement
WRONG
INTRODUCTIONIN-11
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Thickness of
welded portionSize of plug hole
1.0 (0.04) under 5 (0.20)
f over
1.0 (0.04) - 1.5 (0.06) 6.5 (0.26)
f over
1.5 (0.06) over 8 (0.31)
f over
REFERENCE:
mm (in.)
PREPARATION FOR INSTALLATION
SPOT WELD POINTS
APPLICATION OF WELD-THROUGH PRIMER
(SPOT SEALER)
Less than
3 mm
Remove the paint from
the portion of the new
parts and body to be
welded, and apply
weld-through primer.
HINT: See ºANTI-
RUST TREATMENT ºon page AR-9.
When welding panels with a
combined thickness of over
3 mm (0.12 in.), use a MIG
(Metal Inert Gas) welder for
plug welding.
HINT: Spot welding will not
provide sufficient durabilityfor panels over 3 mm (0.12
in.) thick.
Air Saw
WRONG
Puncher
20 - 30 mm
Overlap
ROUGH CUTTING OF JOINT
For joint areas, rough
cut the new parts, leaving
20 - 30 mm (0.79 - 1.18 in.)
overlap. MAKING HOLES FOR PLUG WELDING
For areas where a spot welder cannot
be used, use a puncher or drill to make
holes for plug welding.
INTRODUCTIONIN-12
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INSTALLATION
PRE-WELDING MEASUREMENTS
Always take measurements
before installing underbody
or engine components
to insure correct assembly.
After installation, confirm
proper fit.POST-WELDING REFINISH-
ING
1. Always check the welded
spots to insure they are
secure.
2. When smoothing out the weld spots with a disc
grinder, be careful not to
grind off too much as this
would weaken the weld.
WELDING PRECAUTIONS
1. The number of welding spots
should be as follows.
Spot weld: 1.3 x No. of
manufacturer's spots.
Plug weld: More than No. of
manufacturer's plugs.
WRONG
OKAYWRONG
2. Plug welding should be done
with a MIG (Metal Inert Gas)
welder. Do not gas weld or
braze panels at areas other
than specified.
Safety Glass
Body
Measurement
Diagrams
SPOT WELDING PRECAUTIONS
SPOT WELD LOCATIONS
Try to avoid welding over
previous spots. 1. The shape of the welding
tip point has an effect on
the strength of the weld.
2. Always insure that the seams and welding tip are
free of paint.
Old
Spot
Locations New Spot
Locations
Tip Cutter
INTRODUCTIONIN-13
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ANTI-RUST TREATMENT
When replacing body panels, always apply body sealer, anti-rust agent or undercoat according to the re-
quirements of your country.
HINT: For further details, see the description given in Section AR of this m\
anual.
ANTI-RUST AGENT (WAX)Apply anti-rust agent to
following sections.

Inside of the hems of the
doors and hood.

Around the hinges of the
doors and hood.

Inside of the welded parts
with boxed cross-section.
BODY SEALER
Apply body sealer to the
required areas.
Cartridge
Type
Tube
Type
UNDERCOAT
Apply undercoat to the underbody and
wheel housings.
Spray Gun
Undercoating
(Water base)
Undercoating
(Oil base)
INTRODUCTIONIN-14
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N01093
N01094
SUPPORT POSITION PANTOGRAPH JACK POSITION
Front Center of suspension crossmember. . . . . . . .
Rear Jack up support of differential carrier . . . . . . . . .
JACK POSITION
Jack
or Suspension Crossmember
Front
Safety stand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VEHICLE LIFT AND SUPPORT LOCATIONS
INTRODUCTIONIN-15
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SERVICE SPECIFICATIONS
SERVICE DATA
ThermostatValve opening temperature80±845C176±183 5F
Valve liftat 95 5C (203 5F) 10 mm0.39 in.
Radiator capRelief valve opening pressureSTD74±103 kPa
(0.75±1.05 kgf/cm, 10.7±14.9 psi)
Limit 59 kPa 0.6 kgf/cm 8.5 psi
On±vehicle
itifh
Oil pressure1,177±2,452 kPa
inspection for hy-
draulic cooling(12±25 kgf/cm, 171±356 psi)draulic cooling
fan
fan
Hydraulic pumpSpool valve45.8 mm1.803 in.
Rotor side clearanceSTD Drive rotor 0.02 mm0.0008 in.
Driven rotor 0.03 mm0.0012 in.
Limit Drive rotor 0.03 mm0.0012 in.
Driven rotor 0.04 mm0.0016 in.
Rotor body clearanceSTD 0.05±0.09 mm0.0020±0.0035 in.
Limit 0.10 mm0.0039 in.
Rotor tip clearanceSTD 0.02 mm0.0008 in.
Limit 0.03 mm0.0012 in.
Drive shaft bushing inside diameter17.00±17.05 mm0.6693±0.6713 in.
Drive shaft diameter16.97±16.98 mm0.6681±0.6685 in.
Drive shaft oil clearanceSTD 0.02±0.08 mm0.0008±0.0031 in.
Limit 0.08 mm0.0031 in.
Drive shaft preload (rotating torque)0.3 N Vm 3.0 kgf Vcm 2.6 in. Vlbf
Solenoid valve resistanceat cold 7.5±8.5

Hydraulic motorRotor side clearanceSTD0.01±0.04 mm0.0004±0.0016 in.
Limit 0.05 mm0.0020 mm
Drive shaft hole inside diameter14.000±14.011 mm0.5512±0.5516 in.
Drive shaft diameter13.973±13.984 mm0.5501±0.5506 in.
Drive shaft oil clearanceSTD 0.016±0.038 mm0.0006±0.0015 in.
Limit 0.04 mm0.0031 in.
Drive shaft preload (rotating torque)0.3 NVm 3.0 kgf Vcm 2.6 in. Vlbf
Water temp. Resistanceat 80 5C (176 5F)1.48±1.58 k

sensor
CO±64±
COOLIING SYSTEM Service Specifications
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TORQUE SPECIFICATIONS
Part tightenedNVmkgf Vcmft Vlbf
Engine drain plug X Cylinder block1818013
Coolant filler plug X Water inlet housing44450 33
Water pump X Cylinder block18185 13
Water inlet housing X Water pump18185 13
Water inlet X Water inlet housing18185 13
Radiator fan shroud X Radiator4.950 43 in. Vlbf
Radiator X Body12120 9
Cooling fan reservoir tank X Radiator fan shroud4.950 43 in. Vlbf
Cooling fan inlet pipe X Radiator fan shroud4.950 43 in. Vlbf
Cooling fan pressure hose X Hydraulic motor64650 47
Radiator reservoir tank X Upper radiator support4.950 43 in. Vlbf
Radiator reservoir tank X Radiator reservoir tank support4.950 43 in. Vlbf
Hydraulic pump rear housing X End plug (for spool valve)19200 14
Hydraulic pump front housing X Rear housing21210 15
Hydraulic pump pulley X Drive shaft59600 43
Solenoid valve X Hydraulic pump rear housing39400 28
Hydraulic pump suction port union X Rear housing13135 10
 Hydraulic pump X Cylinder block 12 mm head 16 160 12
  14 mm head 20 310 22
\
 \
Cooling fan pressure hose X Hydraulic pump 64 650 47
\
 \
RH No.2 timing belt cover X Cylinder block 16 160 12
\
 \
Drive belt idler pulley X Hydraulic pump 37 380 27
\
 \
A/C compressor X Hydraulic pump 49 500 36
\
 \
A/C compressor X Cylinder block 49 500 36\
 \
A/C compressor stay X Oil filter bracket 29 300 22\
 \
Hydraulic motor cover X Motor housing 28 290 21\
 
\

\
Hydraulic motor X Radiator fan shroud
 

4.9
 

50
 

43 in.
Vlbf
\
 \
Cooling fan X Hydraulic motor 15 150 11
\
 \
Cooling fan oil cooler X Body 18 180 13
\
 \
Water temperature sensor X Radiator 7.4 75 65 in. Vlbf
±
COOLIING SYSTEM Service SpecificationsCO±65
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COOLING SYSTEM
CO±1±
COOLIING SYSTEM Description
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DESCRIPTION
This engine utilizes a pressurized forced circulation cooling system which i\
ncludes a hermostat equipped
with a by±pass valve mounted on the inlet side. The cooling system is composed of the water jacket (inside the cylinder bl\
ock and cylinderhead), radiator,
water pump, thermostat, cooling fan, hoses and other components.
OPERATION
CO±2±
COOLIING SYSTEM Description
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DESCRIPTION
This engine utilizes a pressurized forced circulation cooling system whi\
ch includes a hermostat equipped
with a by±pass valve mounted on the inlet side. The cooling system is composed of the water jacket (inside the cylinder bl\
ock and cylinderhead), radiator,
water pump, thermostat, cooling fan, hoses and other components.
OPERATION
CO±2±
COOLIING SYSTEM Description
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