Lexus SC300 / Lexus SC400. Manual - part 384

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.

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:

2.440 – 2.490 mm (0.0961 – 0.0980 in.)

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1UZ–FE ENGINE

ENGINE MECHANICAL

EG–159

6.  REMOVE MAIN BEARING CAPS AND CHECK OIL

CLEARANCE

(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:

•

Keep the lower bearing and main bearing cap together.

•

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:

•

Arrange the upper thrust washers in correct order.

•

Keep the upper 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 is damaged, replace the bearings. If
necessary, replace the crankshaft.

EG–160

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1UZ–FE ENGINE

ENGINE MECHANICAL

(h) Install 

the 5 main bearing caps with the 20 nuts and ten bolts.

Do not install the crankshaft.
(See step 4 on page 

EG–180

)

Torque:

Nut

1st

27 N

⋅

m (275 kgf

⋅

cm, 20 ft

⋅

lbf)

2nd Turn 90

°

Bolt

49 N

⋅

m (500 kgf

⋅

cm, 36 ft

⋅

lbf)

(i) 

Using a cylinder gauge, measure the inside diameter of the
the main bearing.

Bearing inside diameter:

67.026 – 67.033 mm (2.6388 – 2.6391 in.)

(j) Using 

a, 

micrometer 

measure 

the 

diameter 

of 

the 

main

journal

Main journal diameter:

66.988 – 67.000 mm (2.6373 – 2.6378 in.)

(k)  Subtract the main journal diameter measurement from the

main bearing inside diameter measurement.

Standard 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.

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1UZ–FE ENGINE

ENGINE MECHANICAL

EG–161

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

EXAMPLE: 

Cylinder block “06” (A)
+ Crankshaft “08” (B)
= Total number 14 (Use bearing “3”)

V01565

Reference:

Cylinder block main journal bore diameter (A):

Mark “00”

72.000 mm (2.8346 in.)

Mark “01”

72.001 mm (2.8347 in.)

Mark “02”

72.002 mm (2.8347 in.)

Mark “03”

72.003 mm (2.8348 in.)

Mark “04”

72.004 mm (2.8348 in.)

Mark “05”

72.005 mm (2.8348 in.)

Mark “06”

72.006 mm (2.8349 in.)

Mark “07”

72.007 mm (2.8349 in.)

Mark “08”

72.008 mm (2.8350 in.)

Mark “09”

72.009 mm (2.8350 in.)

Mark “10”

72.010 mm (2.8350 in.)

Mark “11”

72.011 mm (2.8351 in.)

Mark “12”

72.012 mm (2.8351 in.)

Mark “13”

72.013 mm (2.8352 in.)

EG–162

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1UZ–FE ENGINE

ENGINE MECHANICAL