LEXUS SC400 1991 Service Repair Manual

COMPONENTS FOR DISASSEMBLY AND ASSEMBLY OF CYLINDER BLOCK
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ENGINE MECHANICAL Cylinder BlockEM±131
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PREPARATION FOR DISASSEMBLY
(See Components on page EM±131)
1. REMOVE DRIVE PLATE Remove the eight bolts, two spacers and drive plate.
2. INSTALL ENGINE TO ENGINE STAND FOR DISASSEMBLY
3. REMOVE TIMING BELT AND PULLEYS (See pages EM±36 to 44)
4. REMOVE Cylinder Block (See pages EM±61 to 75)
5. REMOVE RH ENGINE MOUNTING BRACKET Remove the four bolts and mounting bracket.
6. REMOVE LH ENGINE MOUNTING BRACKET (a) Remove the clamp bolt, and disconnect the engine wirefrom the engine mounting bracket.
(b) Remove the four bolts and mounting bracket.
7. REMOVE STARTER (a) Remove the two bolts, and disconnect the starter fromthe cylinder block.
EM±132
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(b) Disconnect the wire clamp from the bracket on thestarter.
(c) Remove the nut, and disconnect the wire.
(d) Disconnect the connector, and remove the starter.
8. REMOVE KNOCK SENSORS (a) Disconnect the two knock sensor connectors.
(b) Using SST, remove the two knock sensors.
SST 09816±30010
9. REMOVE WATER BY±PASS PIPE (a) Remove the two bolts.
(b) Pull out the by±pass pipe from the water pump.
(c) Remove the O±ring from the by±pass pipe.
10. REMOVE ENGINE WIRE (a) Disconnect the following connectors:(1) Oil level sensor connector
(2) Oil pressure switch connector
(b) Remove the three bolts and wire cover from the LH side
of the cylinder block.
(c) Remove the two bolts and engine wire.
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ENGINE MECHANICAL Cylinder BlockEM±133
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11. REMOVE WATER PUMP(a) Remove the five mounting bolt, two mounting stud boltsand mounting nut.
(b) Remove the water pump by prying the portions between
the water pump and cylinder block with a screwdriver.
12. REMOVE NO.2 AND NO.1 OIL PANS (See steps 7 to 12 on pages LU±9 to 11)
13. REMOVE OIL PUMP (a) Remove the eight mounting bolts.
(b) Remove the oil pump by prying the portions between the
oil pump and cylinder block with a screwdriver.
(c) Remove the O±ring from the cylinder block.
14. REMOVE ALTERNATOR BRACKET Remove the bolt and bracket.
15. REMOVE WATER SEAL PLATE
Remove the two nuts and seal plate.
EM±134
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DISASSEMBLY OF CYLINDER BLOCK
(See Components on page EM±131)
1. REMOVE REAR OIL SEAL RETAINER (a) Remove the seven bolts.
(b) Remove the oil seal retainer by prying the portions
between the oil seal retainer and main bearing cap with
a screwdriver.
(c) Remove the O±ring.
2. CHECK CONNECTING ROD THRUST CLEARANCE Using a dial indicator, measure the thrust clearance while
moving the two connecting rods back and forth.
Standard thrust clearance: 0.160±0.290 mm
(0.0063±0.0114 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.)
3. REMOVE CONNECTING ROD CAPS AND CHECK OILCLEARANCE
(a) Using a punch or numbering stamp, place thematchmarks on the connecting rod and cap to ensure
correct reassembly.
(b) Using SST, remove the two connecting rod bolts.
SST 09011±38121
(c) Using the two removed connecting rod bolts, remove the connecting rod cap and lower bearing by wiggling
the connecting rod cap right and left.
HINT: Keep the lower bearing inserted with the connecting rod cap.
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ENGINE MECHANICAL Cylinder BlockEM±135
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(d) Clean the crank pin and bearings.
(e) C h e c k t h e c r a n k p i n a n d b e a r i n g f o r p i t t i n g a n dscratches.
If the crank pin or bearing are damaged, replace the bear-
ings. If necessary, replace the crankshaft.
(f) Lay a strip of Plastigage across the crank pin.
(g) Install the connecting rod cap with the two bolts.
(See step 6 on pages EM±159 and 160)
Torque: 1st 25 N Vm (250 kgf Vcm, 18 ft Vlbf)
2nd Turn 90 5
NOTICE: Do not turn the crankshaft.
(h) Remove the two bolts, connecting rod cap and lower
bearing. (See procedure (b) and (c) above)
(i) Measure the Plastigage at widest point.
Standard oil clearance: 0.027±0.053 mm (0.0011±0.0021 in.)
Maximum oil clearance: 0.065 mm (0.0026 in.)
If the oil clearance is greater than maximum, replace the
bearings. If necessary, replace the crankshaft.
EM±136
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HINT: If using a standard bearing, replace with one having
the same number. If the number of the bearing cannot be de-
termined, select the correct bearing by adding together the
numbers imprinted on the connecting rod cap and crank-
shaft, then selecting the bearing with the same number as the
total. There are six sizes of standard bearings, marked º2º,
º3º, º4º, º5º, º6º and º7º accordingly.
  Number mark 
Connecting rod cap 1 1 2 1 2 3 2 3 4 3 4 4 

Crakshaft
 

1
 

2
 

1
 

3
 

2
 

1
 

3
 

2
 

1
 

3
 

2
 

3
 Use bearing 2 3 4 5 6 7
EXAMPLE: Connecting rod cap º3º + Crankshaft º1º
= Total number 4 (Use bearing º4º)
(Reference)
Connecting rod big end inside diameter:
Mark º1º 55.000±55.006 mm (2.1654±2.1656 in.)
Mark º2º 55.006±55.012 mm (2.1656±2.1658 in.)
Mark º3º 55.012±55.018 mm (2.1658±2.1661 in.)
Mark º4º 55.018±55.024 mm (2.1661±2.1663 in.)
Crankshaft crank pin diameter: Mark º1º 51.994±52.000 mm (2.0470±2.0472 in.)
Mark º2º 51.988±51.994 mm (2.0468±2.0470 in.)
Mark º3º 51.982±51.988 mm (2.0465±2.0468 in.)
Standard sized bearing center wall thickness: Mark º2º 1.484±1.487 mm (0.0584±0.0585 in.)
Mark º3º 1.487±1.490 mm (0.0585±0.0587 in.)
Mark º4º 1.490±1.493 mm (0.0587±0.0588 in.)
Mark º5º 1.493±1.496 mm (0.0588±0.0589 in.)
Mark º6º 1.496±1.499 mm (0.0589±0.0590 in.)
Mark º7º 1.499±1.502 mm (0.0590±0.0591 in.)
(j) Completely remove the Plastigage.
4. REMOVE PISTON AND CONNECTING ROD ASSEMBLIES
(a) Using a ridge reamer, remove all the carbon from the top
of the cylinder.
(b) Push the piston, connecting rod assembly and upper bearing through the top of the cylinder block.
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ENGINE MECHANICAL Cylinder BlockEM±137
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HINT:
wKeep the bearings, connecting rod and cap together.
w Arrange the piston and connecting rod assemblies in
correct order.
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.)
6. REMOVE MAIN BEARING CAP AND CHECK OILCLEARANCE
(a) Remove the ten main bearing cap bolts.
(b) Uniformly loosen and remove the twenty main bearingcap nuts in several passes in the sequence shown.
EM±138
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(c) Using two screwdrivers, pry out the main bearing cap,and remove the five main bearing cap, lower main
bearings and two lower thrust washers (No.3 main
bearing cap only).
NOTICE: Be careful not to damage the cylinder block.
HINT:
w Keep the lower main bearing and main bearing cap
together.
w Arrange the main bearing caps and lower thrust
washers in correct order.
(d) Lift out the crankshaft.
(e) Remove the two upper thrust washers.
HINT:
w Arrange the upper thrust washers in correct order.
w Keep the upper main bearings together with the cylinder
block.
(f) Clean each main journal and bearing.
(g) Check each main journal and bearing for pitting and scratches.
If the journal or bearing are damaged, replace the bearings.
If necessary, replace the crankshaft.
(h) Install the five main bearing caps with the twenty nuts and ten bolts. Do not install the crankshaft.
(See step 4 on pages EM±157 and 158)
Torque:
Nut 1st 27 N Vm (275 kgf Vcm, 20 ft Vlbf)
2nd Turn 90 5
Bolt 49 N Vm (500 kgf Vcm, 36 ft Vlbf)
(i) Using a cylinder gauge, measure the inside diameter of
the main bearing.
Bearing inside diameter: 67.026±67.033 mm
(2.6388±2.6391 in.)
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ENGINE MECHANICAL Cylinder BlockEM±139
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(j) Using a micrometer, measure the diameter of the mainjournal.
Main journal diameter: 66.988±67.000 mm
(2.6373±2.6378 in.)
(k) Subtract the main journal diameter measurement fromthe main bearing inside diameter measurement.
Standard oil clearance: 0.026±0.045 mm
(0.0010±0.0018 in.)
Maximum clearance: 0.055 mm (0.0022 in.)
If the oil clearance is greater than maximum, replace the
bearings. If necessary, replace the crankshaft.
HINT: If using a standard bearing, replace with one having
the same number. If the number of the bearing cannot be de-
termined, select the correct bearing by adding together the
numbers imprinted on the cylinder block and crankshaft, then
refer to the table below for the appropriate bearing number.
There are five sizes of standard bearings, marked º1º, º2º, º3º\
,
º4º and º5º accordingly.
 


 

Total number º º: Number mark
 Cylinder block (A)     
+0±56±1112±1718±2324±28 Crankshaft (B) =     
 Use bearing º1º º2º º3º º4º º5º
EXAMPLE: Cylinder block º06º (A)
+ Crankshaft º08º (B)
= Total number 14 (Use bearing º3º)
(Reference)
Cylinder block main journal bore diameter (A):
Mark º00º 72.000 mm (2.8346 in.)
Mark º01º 72.001 mm (2.8347 in.)
Mark º02º 72.002 mm (2.8347 in.)
Mark º03º 72.003 mm (2.8348 in.)
Mark º04º 72.004 mm (2.8348 in.)
Mark º05º 72.005 mm (2.8348 in.)
Mark º06º 72.006 mm (2.8349 in.)
Mark º07º 72.007 mm (2.8349 in.)
Mark º08º 72.008 mm (2.8350 in.)
Mark º09º 72.009 mm (2.8350 in.)
Mark º10º 72.010 mm (2.8350 in.)
Mark º11º 72.011 mm (2.8351 in.)
Mark º12º 72.012 mm (2.8351 in.)
Mark º13º 72.013 mm (2.8352 in.)
Mark º14º 72.014 mm (2.8352 in.)
Mark º15º 72.015 mm (2.8352 in.)
Mark º16º 72.016 mm (2.8353 in.)
EM±140±
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