LEXUS SC400 1991 Service Repair Manual

INSPECTION OF CRANKSHAFT
1. INSPECT CRANKSHAFT FOR RUNOUT(a) Place the crankshaft on V±blocks.
(b) Using a dial indicator, measure the circle runout at thecenter journal.
Maximum circle runout: 0.08 mm (0.0031 in.)
If the circle runout is greater than maximum, replace the
crankshaft.
2. INSPECT MAIN JOURNALS AND CRANK PINS (a) Using a micr ometer, measure the diameter of each main
journal and crank pin.
Main journal diameter: 66.988±67.000 mm
(2.6373±2.6378 in.)
Crank pin diameter: 51.982±52.000 mm (2.0465±2.0472 in.)
If the diameter is not as specified, check the oil clearance
(See page EM±136 or 139).
(b) Check each main journal and crank pin for taper and out±of±round as shown.
Maximum taper and out±of±round: 0.02 mm
(0.0008 in.)
If the taper or out±of±round is greater than maximum, re-
place the crankshaft.
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REPLACEMENT OF CRANKSHAFT OIL
SEALS
HINT: There are two methods (A and B) to replace the oil seal
which are as follows:
1. REPLACE CRANKSHAFT FRONT OIL SEAL
A. If oil pump is removed from cylinder block: (a) Using a screwdriver, pry out the oil seal.
(b) Using SST and a hammer, tap in a new oil seal until its
surface is flush with the oil pump body edge.
SST 09316±60010 (09316±00010)
(c) Apply MP grease to the oil seal lip.
B. If oil pump is installed to the 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 itssurface is flush with the oil pump body edge.
SST 09316±60010 (09316±00010)
EM±152
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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 itssurface 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 itssurface is flush with the rear oil seal retainer edge.
SST 09223±56010
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ASSEMBLY OF PISTON AND
CONNECTING ROD ASSEMBLIES
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) 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 ºRº, the LH piston with ºLº.
(d) Align the piston pin holes of the piston and connecting rod, and push in the piston pin with your thumb.
(e) Using a small screwdriver, install a new snap ring on the
other side of the piston pin hole.
EM±154
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2. INSTALL PISTON RINGS(a) Install the oil ring expander and two side rails by hand.
(b) U s i n g a p i s t o n r i n g e x pander, install the two
compression rings with the code mark facing upward.
Code mark: No.1 1R or T
No.2 2R or 2T
(c) Position the piston rings so that the ring ends are asshown.
NOTICE: Do not align the piston ring ends.
3. INSTALL BEARINGS (a) Align the bearing claw with the groove of the connectingrod or connecting cap.
(b) I n s t a l l t h e b e a r i n g s i n t h e c onnecting rod and
connecting rod cap.
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ASSEMBLY OF CYLINDER BLOCK
(See Components on page EM±131)
HINT:
w Thoroughly clean all parts to be assembled.
w Before installing the parts, apply new engine oil to all
sliding 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 caps. 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 claw with the claw groove of the cylinder block, and push in the five upper bearings.
(b) Align the bearing claw with the claw groove of the main bearing cap, and push in the five lower bearings.
HINT: A number is marked on each main bearing cap indicat-
ing the installation position.
2. INSTALL UPPER THRUST WASHERS Install the two thrust washers under the No.3 journal position
of the block with the oil grooves facing outward.
EM±156
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3. PLACE CRANKSHAFT ON CYLINDER BLOCK
4. INSTALL MAIN BEARING CAP AND LOWER THRUSTWASHERS
A. Place main bearing cap and lower thrust washers on cyl-
inder block
(a) Install the two thrust washers on the No.3 main bearing cap with the grooves facing outward.
(b) Install the main bearing caps in their proper location.
(c) Place the five bearing caps in position on cylinder block.
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 two
progressive steps (steps (b) and (d)).
w If any one of the main bearing cap stud bolts is broken
or deformed, replace it.
(a) Apply a light coat of engine oil on the threads and under
the nuts of the main bearing caps.
(b) Install and uniformly tighten the twenty 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.
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(c) Mark the front of the main bearing cap nut with paint.
(d) R e t i g h t e n t h e m a i n b e a r i n g c a p n u t s 9 0 5 i n t h enumerical order shown.
(e) Check that the painted mark is now at a 905 angle to the
front.
(f) Check that the crankshaft turns smoothly.
(g) Check the crankshaft thrust clearance. (See step 5 on page EM±138)
C. Install main bearing cap bolts (a) Install a new seal washer to the main bearing cap bolt.
(b) Install the ten main bearing cap bolts.
Torque: 49 N Vm (500 kgf Vcm, 36 ft Vlbf)
5. INSTALL PISTON AND CONNECTING ROD ASSEMBLIES
Using 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 ºRº, the LH piston
with ºLº.
EM±158
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6. INSTALL CONNECTING ROD CAPS
A. Place connecting rod cap on connecting rod(a) Match the numbered c onnecting 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
cap.
(c) Check that the outside mark on the connecting rod cap is facing in correct direction.
B. Install connecting rod cap bolts HINT:
wThe connecting rod cap bolts are tightened in two
progressive steps (steps (b) and (d)).
w If any one of the connecting rod bolts is broken or
deformed, replace it.
(a) Apply a light of engine oil on the threads and under the
heads of the connecting rod cap bolts.
(b) Usin g SS T, in sta ll an d alte rn a te ly tig h te n th e two connecting rod cap bolts in several passes.
SST 09011±38121
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 bolt.
(c) Mark the front of the connecting rod cap bolt with paint.
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(d) Retighten the connecting rod cap bolts 905 in thenumerical order shown.
(e) Check that the painted mark is now at a 905 angle to the
front.
(f) Check that the crankshaft turns smoothly.
(g) Check the connecting rod thrust clearance. (See step 2 on page EM±135)
7. INSTALL REAR OIL SEAL RETAINER (a) Remove any old packing (FIPG) material and be carefulnot to drop any oil on the contact surfaces of the retainer
and cylinder block.
w Using a razor blade and gasket scraper, remove all the
old packing (FIPG) material from the gasket surfaces
and sealing groove.
w Thoroughly clean all components to remove all the
loose material.
w Using a non±residue solvent, clean both sealing
surfaces.
(b) Apply seal packing to the retainer as shown in the illustration.
Seal packing: Part No.08826±00080 or equivalent
wInstall a nozzle that has been cut to a 2±3 mm
(0.08±0.12 in.) opening.
w Parts must be assembled within 3 minutes of
application. Otherwise the material must be removed
and reapplied.
w Immediately remove nozzle from the tube and reinstall
cap.
(c) Place a new O±ring in position on the cylinder block.
(d) Install the retainer with the seven bolts.
Torque: 7.8 N Vm (80 kgf Vcm, 69 in. Vlbf)
EM±160±
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