Lexus SC300 / Lexus SC400. Manual — part 459

HINT:

•

Keep the bearings, connecting rod and cap together.

•

Arrange the piston and connecting rod assemblies in
correct order.

5.

CHECK CRANKSHAFT THRUST CLEARANCE
Using a dial indicator, 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:

1.940–1.990 mm (0.0764–0.0783 in.)

6. REMOVE MAIN BEARING CAPS AND CHECK OIL

CLEARANCE
(a) Remove the main bearing cap bolts.

(b) Using

the removed main bearing cap bolts, pry the main

bearing cap back and forth, and remove the main
bearing caps, lower bearings and lower thrust washers
(No. 4 main bearing cap only).

HINT:

•

Keep the lower bearing and main bearing cap together.

•

Arrange the main bearing caps and lower thrust
washers in correct order.

(c) Lift out the crankshaft.
HINT: Keep the upper bearing and upper thrust washer to-
gether with the cylinder block.

EM–80

–

ENGINE MECHANICAL

Cylinder Block

(d) Clean each main journal and bearing.
(e) Check each main journal and bearing for pitting and

scratches.

If the journal or bearing is damaged, replace the bearings.
If necessary, grind or replace the crankshaft.

(f) Place the crankshaft on the cylinder block.
(g) Lay a strip of Plastigage across each journal.

(h) Install the main bearing caps.

(See step 4 on pages EM–97 and 98)

Torque: 1st 44

N

⋅

m (450 kgf

⋅

cm, 33 ft

⋅

lbf)

2nd turn

90

°

HINT: Do not turn the crankshaft.

(i)

Remove the main bearing caps.

(See procedures (a) and (b) above)

(j)

Measure the Plastigage at its widest point.

Standard clearance:

STD size

0.026–0.040 mm
(0.0010–0.0016 in.)

U/S 0.25

0.025–0.061 mm

(0.0010–0.0024 in.)

Maximum clearance:

STD size

0.06 mm (0.0024 in.)

U/S 0.25

0.08 mm (0.0031 in.)

If the oil clearance is greater than maximum, replace the bearings.
If necessary, replace the crankshaft.

–

ENGINE MECHANICAL

Cylinder Block

EM–81

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 ”1”, ”2”, ”3”,
”4” and ”5” accordingly.

ÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑ

ÑÑÑÑÑÑ

Total number

ÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑ

””: Number mark

ÑÑÑÑÑÑÑÑ

Cylinder block (A)

ÑÑÑ

ÑÑÑÑ

ÑÑÑ

ÑÑÑ

ÑÑÑÑ

ÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑ

+

0–2

3–5

6–8

9–11

12–14

ÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑ

Crankshaft (B) =

ÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑ

Use bearing

ÑÑÑ

ÑÑÑ

”1”

ÑÑÑÑ

ÑÑÑÑ

”2”

ÑÑÑ

ÑÑÑ

”3”

ÑÑÑ

ÑÑÑ

”4”

ÑÑÑÑ

ÑÑÑÑ

”5”

EXAMPLE: Cylinder block ”3” (A)

+ Crankshaft ”4” (B)

= Total number 7 (Use bearing ”3”)

(Reference)

Cylinder block main journal bore diameter (A):

Mark ”0”

66.020–66.022 mm

(2.59921–2.59929 in.)

Mark ”1”

66.022–66.024 mm

(2.59929–2.59937 in.)

Mark ”2”

66.024–66.026 mm

(2.59937–2.59945 in.)

Mark ”3”

66.026–66.028 mm

(2.59945–2.59953 in.)

Mark ”4”

66.028–66.030 mm

(2.59953–2.59961 in.)

Mark ”5”

66.030–66.032 mm

(2.59961–2.59969 in.)

Mark ”6”

66.032–66.034 mm

(2.59969–2.59976 in.)

Mark ”7”

66.034–66.036 mm

(2.59976–2.59984 in.)

U/S 0.25

66.020–66.036 mm

(2.59921–2.59984 in.)

Crankshaft main journal diameter (B):

Mark ”0”

61.998–62.000 mm

(2.44087–2.44095 in.)

Mark ”1”

61.996–61.998 mm

(2.44079–2.44087 in.)

Mark ”2”

61.994–61.996 mm

(2.44071–2.44079 in.)

Mark ”3”

61.992–61.994 mm

(2.44063–2.44071 in.)

Mark ”4”

61.990–61.992 mm

(2.44055–2.44063 in.)

Mark ”5”

61.988–61.990 mm

(2.44047–2.44055 in.)

Mark ”6”

61.986–61.988 mm

(2.44039–2.44047 in.)

Mark ”7”

61.984–61.986 mm

(2.44031–2.44039 in.)

U/S 0.25

61.745–61.755 mm

(2.43091–2.43130 in.)

EM–82

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ENGINE MECHANICAL

Cylinder Block

Bearing center wall thickness:

Mark ”1”

1.994–1.997 mm

(0.0785–0.0786 in.)

Mark ”2”

1.997–2.000 mm

(0.0786–0.0787 in.)

Mark ”3”

2.000–2.003 mm

(0.0787–0.0789 in.)

Mark ”4”

2.003–2.006 mm

(0.0789–0.0790 in.)

Mark ”5”

2.006–2.009 mm

(0.0790–0.0791 in.)

U/S 0.25

2.114–2.120 mm

(0.0832–0.0835 in.)

Standard sized Bearing Selection Chart

ÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑ

Crankshaft number mark

ÑÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑÑ

Cylinder block number mark

ÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑ

Crankshaft number mark

0

1

2

3

4

5

6

7

ÑÑÑÑÑÑÑÑÑÑ

0

ÑÑÑ

1

ÑÑ

1

ÑÑ

1

ÑÑ

2

ÑÑ

2

ÑÑ

2

ÑÑÑ

3

ÑÑ

3

ÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑ

1

ÑÑÑ

ÑÑÑ

1

ÑÑ

ÑÑ

1

ÑÑ

ÑÑ

2

ÑÑ

ÑÑ

2

ÑÑ

ÑÑ

2

ÑÑ

ÑÑ

3

ÑÑÑ

ÑÑÑ

3

ÑÑ

ÑÑ

3

ÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑ

2

ÑÑÑ

ÑÑÑ

1

ÑÑ

ÑÑ

2

ÑÑ

ÑÑ

2

ÑÑ

ÑÑ

2

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

3

ÑÑÑ

ÑÑÑ

3

ÑÑ

ÑÑ

4

ÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑ

3

ÑÑÑ

ÑÑÑ

2

ÑÑ

ÑÑ

2

ÑÑ

ÑÑ

2

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

3

ÑÑÑ

ÑÑÑ

4

ÑÑ

ÑÑ

4

ÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑ

4

ÑÑÑ

ÑÑÑ

2

ÑÑ

ÑÑ

2

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

4

ÑÑÑ

ÑÑÑ

4

ÑÑ

ÑÑ

4

ÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑ

5

ÑÑÑ

ÑÑÑ

2

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

4

ÑÑ

ÑÑ

4

ÑÑÑ

ÑÑÑ

5

ÑÑ

ÑÑ

5

ÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑ

6

ÑÑÑ

ÑÑÑ

3

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

4

ÑÑ

ÑÑ

4

ÑÑ

ÑÑ

5

ÑÑÑ

ÑÑÑ

5

ÑÑ

ÑÑ

5

ÑÑÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑÑÑ

7

ÑÑÑ

ÑÑÑ

3

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

4

ÑÑ

ÑÑ

4

ÑÑ

ÑÑ

5

ÑÑ

ÑÑ

5

ÑÑÑ

ÑÑÑ

5

ÑÑ

ÑÑ

5

EXAMPLE: Cylinder block ”3”, Crankshaft ”4”

= Use bearing ”3”

(k) Completely remove the Plastigage.

7. REMOVE

CRANKSHAFT

(a) Lift out the crankshaft
(b) Remove the upper bearings and upper thrust washers

from the cylinder block.

HINT: Arrange the main bearing caps, bearings and thrust
washers in correct order.

–

ENGINE MECHANICAL

Cylinder Block

EM–83