ect LEXUS SC300 1991 Service Repair Manual

(d) Clean the crank pin and bearing.
(e) Check the crank pin and bearing for pitting and scratches.If the crank pin or bearing is damaged, replace the bearings.
If necessary, replace the crankshaft.
(f) Lay a strip of Plastigage across the crank pin.
(g) Install the connecting rod cap with the 2 bolts. (See step 7 on page EG±183)
Torque:
1st 25 N Vm (250 kgf Vcm, 18 ft Vlbf)
2nd Turn 90 5
NOTICE: Do not turn the crankshaft.
(h) Remove the 2 bolts, connecting rod cap and lower bearing. (See procedure (b) and (c) above)
(i) Measure the Plastigage at its 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.
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HINT: If using a standard bearing, replace it 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 6 sizes of standard bearings, marked ª2º, ª3º,
ª4º, ª5º, ª6º and ª7º accordingly.
EXAMPLE: Connecting rod cap ª3º + Crankshaft ª1º = Total
number 4 (Use bearing ª4º)
V01595
Reference:
Connecting rod big end inside diameter:
Mark ª1º55.000 ± 55.006 mm (2.1654 ± 2.1656 in.)
Mark ª2º
55.006 ± 55.012 mm (2.1656 ± 2.1658 in.)
Mark ª3º 55.012 ± 55.018 mm (2.1658 ± 2.1661 in.)
Mark ª4º
55.018 ± 55.024 mm (2.1661 ± 2.1663 in.)
Crankshaft crank pin diameter: Mark ª1º51.994 ± 52.000 mm (2.0470 ± 2.0472 in.)
Mark ª2º
51.988 ± 51.994 mm (2.0468 ± 2.0470 in.)
Mark ª3º 51.982 ± 51.988 mm (2.0465 ± 2.0468 in.)
Standard sized bearing center wall thickness:
Mark ª2º1.484 ± 1.487 mm (0.0584 ± 0.0585 in.)
Mark ª3º 1.487 ± 1.490 mm (0.0585 ± 0.0587 in.)
Mark ª4º
1.490 ± 1.493 mm (0.0587 ± 0.0588 in.)
Mark ª5º 1.493 ± 1.496 mm (0.0588 ± 0.0589 in.)
Mark ª6º
1.496 ± 1.499 mm (0.0589 ± 0.0590 in.)
Mark ª7º 1.499 ± 1.502 mm (0.0590 ± 0.0591 in.)
(j) Completely remove the Plastigage.
EG±158
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4. REMOVE PISTON AND CONNECTING RODASSEMBLIES
(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.
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.)
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6. REMOVE MAIN BEARING CAPS AND CHECK OILCLEARANCE
(a) Remove the 10 main bearing cap bolts.
(b) Uniformly loosen and remove the 20 main bearing cap nuts
in several passes, in the sequence shown.
(c) Using 2 screwdrivers, pry out the main bearing cap, and remove the 5 main bearing caps, lower bearings and lower
thrust washers (No.3 main bearing cap only).
NOTICE: Be careful not to damage the cylinder block.
HINT:
wKeep the lower 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 2 upper thrust washers. HINT:
wArrange the upper thrust washers in correct order.
w Keep the upper bearings together with the cylinder
block.
(f) Clean each main journal and bearing.
(g) Ch e ck ea ch ma in jo u rn a l an d be a rin g fo r pittin g an d scratches.
If the journal or bearing is damaged, replace the bearings. If
necessary, replace the crankshaft.
EG±160
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HINT: If using a standard bearing, replace it 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 5 sizes of the standard bearings, marked ª1º, ª2º,\
ª3º, ª4º and ª5º accordingly.
EXAMPLE: Cylinder block ª06º (A) + Crankshaft ª08º (B)
= Total number 14 (Use bearing ª3º)
V01565
Reference:
Cylinder block main journal bore diameter (A):
Mark ª00º72.000 mm (2.8346 in.)
Mark ª01º 72.001 mm (2.8347 in.)
Mark ª02º 72.002 mm (2.8347 in.)
Mark ª03º 72.003 mm (2.8348 in.)
Mark ª04º 72.004 mm (2.8348 in.)
Mark ª05º 72.005 mm (2.8348 in.)
Mark ª06º
72.006 mm (2.8349 in.)
Mark ª07º 72.007 mm (2.8349 in.)
Mark ª08º
72.008 mm (2.8350 in.)
Mark ª09º 72.009 mm (2.8350 in.)
Mark ª10º 72.010 mm (2.8350 in.)
Mark ª11º 72.011 mm (2.8351 in.)
Mark ª12º 72.012 mm (2.8351 in.)
Mark ª13º 72.013 mm (2.8352 in.)
EG±162±
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Standard sized Bearing Selection Chart
 


Crankshaft
number mark\
 
\

\

Cylinder block number mark
  00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16
 00 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3
 01 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3
 02 1 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3 4
 03 1 1 1 2 2 2 2 2 2 3 3 3 3 3 3 4 4 04 1 1 2 2 2 2 2 2 3 3 3 3 3 3 4 4 4 

05
 

1
 

2
 

2
 

2
 

2
 

2
 

2
 

3
 


3


3
 

3
 

3
 

3
 

4
 

4
 

4
 

4
 06 2 2 2 2 2 2 3 3 3 3 3 3 4 4 4 4 4
 07 2 2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4
 08 2 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 5
 09 2 2 2 3 3 3 3 3 3 4 4 4 4 4 4 5 5
 10 2 2 3 3 3 3 3 3 4 4 4 4 4 4 5 5 5 11 2 3 3 3 3 3 3 4 4 4 4 4 4 5 5 5 5 

12
 

3
 

3
 

3
 

3
 

3
 

3
 

4
 

4
 


4


4
 

4
 

4
 

5
 

5
 

5
 

5
 

5
EXAMPLE: Cylinder block ª06º, Crankshaft ª08º
= Use bearing ª3º
V01566
(l) Remove the 10 bolts, 20 nuts and 5 main bearing caps. (Seeprocedure (a) to (c) above)
(m) Remove the 5 upper main bearings from the cylinder block.
HINT: Arrange the main bearing caps, bearings and thrust
washers in correct order.
EG±164
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CYLINDER BLOCK INSPECTION AND
REPAIR
EG1KU±01
1. CLEAN CYLINDER BLOCK
A. Remove gasket materialUsing a gasket scraper, remove all the gasket material from
the top surface of the cylinder block.
B. Clean cylinder block
Using a soft brush and solvent, thoroughly clean the cylinder
block.
NOTICE: If the cylinder is washed at high temperatures, the
cylinder liner sticks out beyond the cylinder block, so always
wash the cylinder block at temperature of 45
or less.
2. INSPECT TOP SURFACE OF CYLINDER BLOCK FOR
FLATNESS
Using a precision straight edge and feeler gauge, measure
the surface contacting the cylinder head gasket for warpage.
Maximum warpage:
0.07 mm (0.0028 in.)
If warpage is greater than maximum, replace the cylinder
block.
3. INSPECT CYLINDER FOR VERTICAL SCRATCHES Visually check the cylinder for vertical scratches.
If deep scratches are present, replace the cylinder block.
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4. INSPECT CYLINDER BORE DIAMETERHINT: There are 3 sizes of the standard cylinder bore diame-
ter, marked ª1º, ª2º and ª3º accordingly. The mark is stamped
on the top of the cylinder block.
Using a cylinder gauge, measure the cylinder bore diameter
at positions A, B and C in the thrust and axial directions.
Standard diameter:
Mark ª1º87.500 ± 87.510 mm (3.4449 ± 3.4453 in.)
Mark ª2º 87.510 ± 87.520 mm (3.4453 ± 3.4457 in.)
Mark ª3º 87.520 ± 87.530 mm (3.4457 ± 3.4461 in.)
Maximum diameter: 87.73 mm (3.4539 in.)
If the diameter is greater than maximum, replace the cylinder
block.
5. REMOVE CYLINDER RIDGE If the wear is less than 0.2 mm (0.008 in.), using a ridge ream-
er, grind the top of the cylinder.
6. INSPECT MAIN BEARING CAP STUD BOLTS Using a vernier caliper, measure the tension portion diameter
of the stud bolt.
Standard diameter:
7.500 ± 7.600 mm (0.2953 ± 0.2992 in.)
Minimum diameter: 7.40 mm (0.2913 in.)
If the diameter is less than minimum, replace the stud bolt.
EG±166
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7. IF NECESSARY, REPLACE MAIN BEARING CAP STUDBOLTS
(a) Using the 2 main bearing cap nuts, remove the stud bolt.
(b) Apply a light coat of engine oil on the threads and under
flange of new stud bolts.
(c) Using the 2 main bearing cap nuts, install the stud bolt.
Torque: 15 N Vm (150 kgf Vcm, 11 ft Vlbf)
HINT: Stud bolts come in lengths of 90.0 mm (3.543 in.) and
101.5 mm (3.996 in.). Install the 101.5 mm (3.996 in.) bolts
in inside positions. Install the 90.0 mm (3.543 in.) bolts in out-
side positions.
PISTON AND CONNECTING ROD
DISASSEMBLY
EG0BV±06
1. CHECK FIT BETWEEN PISTON AND PISTON PIN
Try to move the piston back and forth on the piston pin.
If any movement is felt, replace the piston and pin as a set.
2. REMOVE PISTON RINGS
(a) Using a piston ring expander, remove the 2 compression rings.
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(b) Remove the 2 side rails and oil ring by hand.HINT: Arrange the piston rings in correct order only.
3. DISCONNECT CONNECTING ROD FROM PISTON
(a) Using a small screwdriver, pry out the 2 snap rings.
(b) Gradually heat the piston to approx. 60
C (140
F).
(c) Using a plastic±faced hammer and brass bar, lightly tap out the piston pin and pin and remove the connecting rod.
EG±168
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