Lexus SC300 / Lexus SC400. Manual — part 458

PREPARATION FOR DISASSEMBLY

(See Components on pages EM–74 and 75)

1. (M/T)

REMOVE FLYWHEEL

2. (A/T)

REMOVE DRIVE PLATE
Remove the eight bolts, two spacers and drive plate.

3. INSTALL ENGINE TO ENGINE STAND FOR

DISASSEMBLY

4. REMOVE

GENERATOR

5. REMOVE THROTTLE BODY WITH INTAKE AIR

CONNECTOR (See pages EM–10 to 11)

6.

REMOVE TIMING BELT AND PULLEYS
(See pages EM–24 to 26)

7.

REMOVE WATER PUMP AND BY–PASS HOSE

8.

REMOVE FUEL PRESSURE PULSATION DAMPER

9. REMOVE

CYLINDER

HEAD

(See pages EM–36 to 40)

10. REMOVE FUEL PIPE SUPPORT

11. REMOVE OIL PRESSURE SWITCH AND KNOCK

SENSORS
SST 09816–30010

12. REMOVE LH ENGINE MOUNTING BRACKET
13. REMOVE RH ENGINE MOUNTING BRACKET

14. REMOVE OIL FILTER BRACKET

(a) Remove the union bolt and oil filter bracket.
(b) Remove the gasket from the union bolt.
(c) Remove the O–ring from the oil filter bracket.

15. REMOVE OIL PUMP (See page LU–10)

EM–76

–

ENGINE MECHANICAL

Cylinder Block

DISASSEMBLY OF CYLINDER BLOCK

(See Components on page EM–75)

1.

REMOVE REAR OIL SEAL RETAINER
(a) Remove the six bolts.
(b) Remove

the

oil

seal retainer by prying the area between

the oil seal retainer and main bearing cap with a
screwdriver.

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: 0.250–0.402 mm

(0.0098–0.0158 in.)

Maximum thrust clearance: 0.50 mm (0.0197 in.)

If the thrust clearance is greater than maximum, replace the
connecting rod assembly(s). If necessary, replace the crank-
shaft.

Connecting rod thickness: 25.898–25.950 mm

(1.0196–1.0217 in.)

3. REMOVE CONNECTING ROD CAPS AND CHECK OIL

CLEARANCE
(a) Check the matchmarks on the connecting rod and cap.

(b) Remove the connecting rod cap bolts.

(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.

–

ENGINE MECHANICAL

Cylinder Block

EM–77

(d) Clean the crank pin and bearings.
(e) Check the crank pin and bearing for pitting and

scratches.

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–98 and 99)

Torque:

1st

29 N

⋅

m (300 kgf

⋅

cm, 22 ft

⋅

lbf)

2nd turn

90

°

HINT: Do not turn the crankshaft.

(h) Remove the two bolts, connecting rod cap and lower

bearing. (See procedures (b) and (c) above)

(i)

Measure the Plastigage at widest point.

Standard oil clearance:

STD size

0.035–0.053 mm

(0.0014–0.0021 in.)

U/S 0.25

0.040–0.078 mm

(0.0016–0.0031 in.)

Maximum oil clearance:

STD size

0.08 mm (0.0031 in.)

U/S 0.25

0.09 mm (0.0035 in.)

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

EM–78

–

ENGINE MECHANICAL

Cylinder Block

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 select the bearing with the same number as the
total. There are five sizes of standard bearings, marked ”1”,
”2”, ”3”, ”4” and ”5” accordingly.

ÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑ

Number mark

ÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑ

Connecting rod cap

1

2

3

ÑÑÑÑÑÑÑÑ

Crankshaft

ÑÑ

0

ÑÑ

1

ÑÑ

2

ÑÑ

0

ÑÑ

1

ÑÑ

2

ÑÑ

0

ÑÑ

1

ÑÑ

2

ÑÑÑÑÑÑÑÑ

ÑÑÑÑÑÑÑÑ

Use bearing

ÑÑ

ÑÑ

1

ÑÑ

ÑÑ

2

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

2

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

4

ÑÑ

ÑÑ

3

ÑÑ

ÑÑ

4

ÑÑ

ÑÑ

5

EXAMPLE: Connecting rod cap ”3” + Crankshaft ”1” = Total
number 4 (Use bearing ”4”)
(Reference)
Connecting rod big end inside diameter:

Mark ”1”

55.025–55.031 mm

(2.1663–2.1666 in.)

Mark ”2”

55.031–55.037 mm

(2.1666–2.1668 in.)

Mark ”3”

55.037–55.043 mm

(2.1668–2.1670 in.)

U/S 0.25

55.025–55.043 mm

(2.1663–2.1670 in.)

Crankshaft crank pin diameter:

Mark ”0”

51.994–52.000 mm

(2.0470–2.0472 in.)

Mark ”1”

51.988–51.994 mm

(2.0468–2.0470 in.)

Mark ”2”

51.982–51.988 mm

(2.0465–2.0468 in.)

U/S 0.25

51.745–51.755 in.)

(2.0364–2.0376 in.)

Bearing center wall thickness:

Mark ”1”

1.492–1.495 mm

(0.0587–0.0589 in.)

Mark ”2”

1.495–1.498 mm

(0.0589–0.0590 in.)

Mark ”3”

1.498–1.501 mm

(0.0590–1.501 in.)

Mark ”4”

1.501–1.504 mm

(0.0591–0.0592 in.)

Mark ”5”

1.504–1.507 mm

(0.0592–0.0593 in.)

U/S 0.25

1.610–1.615 mm

(0.0634–0.0636 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 Block

EM–79