1991 LEXUS SC400 engine

2. REPLACE CRANKSHAFT REAR OIL SEAL
A. If rear oil seal retainer is removed from cylinder block:
(a) Using a screwdriver and hammer, tap out the oil seal.
(b) Using SST and a hammer, tap in a new oil seal until its surface
is flush with the rear oil seal retainer edge.
SST 09223±56010
(c) Apply MP grease to the oil seal lip.
B. If rear oil seal retainer is installed to cylinder block:
(a) Using a knife, cut off the oil seal lip.
(b) Using a screwdriver, pry out the oil seal. NOTICE: Be careful not to damage the crankshaft. Tape
the screwdriver tip.
(c) Apply MP grease to a new oil seal lip.
(d) Using SST and a hammer, tap in the oil seal until its surface is flush with the rear oil seal retainer edge.
SST 09223±56010
EG±176
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PISTON AND CONNECTING ROD
ASSEMBLY
EG0C1±07
1. ASSEMBLE PISTON AND CONNECTING ROD
(a) Using a small screwdriver, install a new snap ring on one side
of the piston pin hole.
(b) Gradually heat the piston to about 60
C (140
F).
(c) Coat the piston pin with engine oil.
(d) Position the piston front mark with respect to the outside mark
on the connecting rod as shown in the diagram.
NOTICE: The installation direction of the piston and con-
necting rod are different for the RH and LH banks. The RH
piston is marked with ªRº, the LH piston with ªLº.
(e) Align the piston pin holes of the piston and connecting rod,
and push in the piston pin with your thumb.
(f) Using a small screwdriver, install a new snap ring on the other
side of the piston pin hole.
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2. INSTALL PISTON RINGS
(a) Install the oil ring expander and 2 side rails by hand.
(b) Using a piston ring expander, install the 2 compression ringswith the code mark facing upward.
Code mark:
No.11R or T
No.2 2R or 2T
(c) Position the piston rings so that the ring ends are as shown. NOTICE: Do not align the ring ends.
3. INSTALL BEARINGS
(a) Align the bearing claw with the groove of the connecting rod or connecting cap.
(b) Install the bearings in the connecting rod and connecting rod cap.
EG±178
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CYLINDER BLOCK ASSEMBLY
EG1KW±01
(See Components for Cylinder block Disassembly and As-sembly)
HINT:
wThoroughly clean all parts to be assembled.
w Before installing the parts, apply new engine oil to all
sliding and and rotating surfaces.
w Replace all gaskets. O±rings and oil seals with new
parts.
1. INSTALL MAIN BEARINGS HINT:
wMain bearings come in widths of 19.5 mm (0.768 in.) and
22.5 mm (0.886 in.). Install the 22.5 mm (0.886 in.)
bearings in the No.1 and No.5 cylinder block journal
positions with the main bearing cap. Install the 19.5 mm
(0.768 in.) bearings in the other positions.
w Upper bearings have an oil groove and oil holes lower
bearings do not.
(a) Align the bearing law with the claw groove of the cylinder block, and push in the 5 upper bearings.
(b) Align the bearing claw with the claw groove of the main bearing cap, and push in the 5 lower bearings.
HINT: A number is marked on each main bearing cap to indi-
cate the installation position.
2. INSTALL UPPER THRUST WASHERS Install the 2 thrust washers under the No.3 journal position of
the cylinder block with the oil grooves facing outward.
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3. PLACE CRANKSHAFT ON CYLINDER BLOCK
4. INSTALL MAIN BEARING CAPS AND LOWER THRUSTWASHERS
A. Place main bearing caps and lower thrust washers on
cylinder block
(a) Install the 2 thrust washers on the No.3 bearing cap with the grooves facing outward.
(b) Install the 5 main bearing caps in their proper locations.
HINT: Place the bearing caps level and let them return to their
original position by their own weight.
NOTICE: Do not install the main bearing cap by tapping
it.
B. Install main bearing cap nuts HINT:
wThe main bearing cap nuts are tightened in 2
progressive steps (steps (b) and (d)).
w If any one of the main bearing cap stud nuts is broken
or deformed, replace it.
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(a) Apply a light coat of engine oil on the threads and under themain bearing cap nuts.
(b) Install and uniformly tighten the 20 main bearing cap nuts in
several passes, in the sequence shown.
Torque: 27 N Vm (275 kgf Vcm, 20 ft Vlbf)
If any one of the main bearing cap nuts does not meet the
torque specification, replace the main bearing cap stud bolt.
(c) Mark the front of the main bearing cap nut with paint.
(d) Retighten the main bearing cap bolts 90
in the numerical
order shown.
(e) Check that the painted mark is now at a 90
angle to the front.
C. Install main bearing cap bolts
(a) Install a new seal washer to the main bearing cap bolt.
(b) Install and uniformly tighten the 10 main bearing cap bolts.
Torque: 49 N Vm (500 kgf Vcm, 36 ft Vlbf)
(c) Check that the crankshaft turns smoothly.
5. CHECK CRANKSHAFT THRUST CLEARANCE
Using a dial indi cator, measure the thrust clearance while pry-
ing the crankshaft back and forth with a screwdriver.
Standard thrust clearance:
0.020 ± 0.220 mm (0.0008 ± 0.0087 in.)
Maximum thrust clearance: 0.30 mm (0.0118 in.)
If the thrust clearance is greater than maximum, replace the
thrust washers as a set.
Thrust washer thickness:2.440 ± 2.490 mm (0.0961 ± 0.0980 in.)
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6. INSTALL PISTON AND CONNECTING ROD ASSEMBLESUsing a piston ring compressor, push the correctly numbered
piston and connecting rod assemblies into each cylinder with
the front mark of the piston facing forward.
NOTICE: The shape of the piston varies for the RH and LH
banks. The RH piston is marked with ªRº, the LH piston
with ªLº.
7. INSTALL CONNECTING ROD CAPS
A. Place connecting rod cap on connecting rod
(a) Match the numbered connecting rod cap with the connecting rod.
(b) Align the pin groove of the connecting rod cap with the pins of the connecting rod, and install the connecting rod.
(c) Check that the outside mark of the connecting rod cap is facing in correct direction.
EG±182
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B. Install connecting rod cap boltsHINT:
wThe connecting rod cap bolts are tightened in 2
progressive steps (steps (b) and (d)).
w If any one of the connecting rod cap bolts is broken or
deformed, replace it.
(a) Apply a light coat of engine oil on the threads and under the heads of the connecting rod cap bolts.
(b) Install and alternately tighten the 2 connecting rod cap bolts
in several passes.
Torque: 25 N Vm (250 kgf Vcm, 18 ft Vlbf)
If any one of the connecting rod cap bolts does not meet the
torque specification, replace the connecting rod cap bolts.
(c) Mark the front of the connecting cap bolt with paint.
(d) Retighten the cap nuts 90
as shown.
(e) Check that the painted mark is now at a 90
angle to the front.
(f) Check that the crankshaft turns smoothly.
8. CHECK CONNECTING ROD OIL CLEARANCE
Using a dial indicator, measure the thrust clearance while
moving the connecting rod back and forth.
Standard thrust clearance:
0.160 ± 0.290 mm (0.0063 ± 0.0138 in.)
Maximum thrust clearance: 0.35 mm (0.0138 in.)
If the thrust clearance is greater than maximum, replace the
connecting rod assembly(s). If necessary, replace the crank-
shaft.
Connecting rod thickness:22.880 ± 22.920 mm (0.9008 ± 0.9024 in.)
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