Lexus RX300 (MCU15). Manual — part 452

P12695

P13329

P12707

P12696

P12728

Plastigage

EM–92

–

ENGINE MECHANICAL

CYLINDER BLOCK

LEXUS RX300 (RM785E)

23.

CHECK CONNECTING ROD THRUST CLEARANCE

Using a dial indicator, measure the thrust clearance while mov-
ing the connecting rod back and forth.

Standard thrust clearance:
0.15 – 0.30 mm (0.0059 – 0.0118 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:
20.80 – 20.85 mm (0.8189 – 0.8209 in.)

24.

REMOVE CONNECTING ROD CAPS AND CHECK
OIL CLEARANCE

(a)

Check the matchmarks on the connecting rod and cap are
aligned to ensure correct reassembly.

(b)

Remove the 2 connecting rod cap bolts.

(c)

Using the 2 removed connecting rod cap 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.

(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.

P12697

P12698

P14127

Number Mark

Number
Mark

A05258

–

ENGINE MECHANICAL

CYLINDER BLOCK

EM–93

LEXUS RX300 (RM785E)

(g)

Install the connecting rod cap with the 2 bolts.
(See page EM–108)
Torque:
1st: 24.5 N·m (250 kgf·cm, 18 ft·lbf)
2nd: Turn extra 90°

NOTICE:
Do not turn the crankshaft.
(h)

Remove the 2 bolts, connecting rod cap and lower bear-
ing. (See procedure (b) and (c) above)

(i)

Measure the Plastigage at its widest point.
Standard oil clearance:
0.038 – 0.064 mm (0.0015 – 0.0025 in.)
Maximum oil clearance:
0.08 mm (0.0031 in.)

If the oil clearance is greater than maximum, replace the bear-
ings. If necessary, grind or replace the crankshaft.

HINT:
If replacing a bearing, replace it with one having the same num-
ber as marked on the connecting rod. There are 4 sizes of stan-
dard bearings, marked ”1”, ”2”, ”3” and ”4” accordingly.

Reference:
Standard bearing center wall thickness:

Mark

mm (in.)

”1”

1.484 – 1.487 (0.0584 – 0.0585)

”2”

1.487 – 1.490 (0.0585 – 0.0587)

”3”

1.490 – 1.493 (0.0587 – 0.0588)

”4”

1.493 – 1.496 (0.0588 – 0.0589)

(j)

Completely remove the Plastigage.

25.

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:

S

Keep the bearings, connecting rod and cap together.

S

Arrange the piston and connecting rod assemblies in the
correct order.

P12799

P12585

8

7

6

1

5

2

3

4

P12752

8

7

6

1

5

2

3

4

9

10

13

14

15

16

11

12

P12603

S06200

Joint Surface

EM–94

–

ENGINE MECHANICAL

CYLINDER BLOCK

LEXUS RX300 (RM785E)

26.

CHECK CRANKSHAFT THRUST CLEARANCE

Using a dial indicator, measure the thrust clearance while prying
the crankshaft back and forth with a screwdriver.

Standard thrust clearance:
0.04 – 0.24 mm (0.0016 – 0.0095 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:
1.930 – 1.980 mm (0.0760 – 0.0780 in.)

27.

REMOVE MAIN BEARING CAPS AND CHECK OIL
CLEARANCE

(a)

Uniformly loosen and remove the 8 main bearing cap
bolts and seal washers in the several passes, in the se-
quence shown.

(b)

Uniformly loosen and remove the 16 main bearing cap
bolts in several passes, in the sequence shown.

(c)

Using a screwdriver, pry out main bearing caps. Remove
the 4 main bearing caps, lower bearings and (No.2 main
bearing cap only) 2 lower thrust washers.

NOTICE:
Pull up the main bearing cap little by little to the right and
the left by turns and pay attention not to damage the joint
surface of the cylinder block and the main bearing cap.
HINT:

S

Keep the lower bearing and main bearing cap together.

S

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

P12495

P12980

Plastigage

P12954

P12993

–

ENGINE MECHANICAL

CYLINDER BLOCK

EM–95

LEXUS RX300 (RM785E)

(d)

Lift out the crankshaft.

HINT:
Keep the upper bearings together with the cylinder block.
(e)

Clean each main journal and bearing.

(f)

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.

(g)

Place the crankshaft on the cylinder block.

(h)

Lay a strip of Plastigage across each journal.

(i)

Install the 4 main bearing caps.
(See page EM–108)
Torque:
12 pointed head bolts:
1st: 22 N·m (225 kgf·cm, 16 ft·lbf)
2nd: Turn extra 90°
Hexagon head bolts:
27 N·m (275 kgf·cm, 20 ft·lbf)

NOTICE:
Do not turn the crankshaft.
(j)

Remove the main bearing caps.
(See procedures (a) to (c) above)

(k)

Measure the Plastigage at its widest point.
Standard oil clearance:
No. 1 and No. 4 journals:
0.014 – 0.034 mm (0.0006 – 0.0013 in.)
No. 2 and No. 3 journals:
0.026 – 0.046 mm (0.0010 – 0.0018 in.)
Maximum clearance:
No. 1 and No. 4 journals: 0.05 mm (0.0020 in.)
No. 2 and No. 3 journals: 0.06 mm (0.0024 in.)

If the oil clearance is greater than maximum, replace the bear-
ings. If necessary, replace the crankshaft.