Lexus SC300 / Lexus SC400. Service manual — part 589

2. INSTALL

PISTON

RINGS

(a) Install the oil ring expander and two side rails by hand.

(b) Using a piston ring expander, install the two

compression rings with the code mark facing upward.

Code mark: No.1 1R or T

No.2 2R or 2T

(c) Position the piston rings so that the ring ends are as

shown.

NOTICE: Do not align the piston ring ends.

3. INSTALL

BEARINGS

(a) Align the bearing claw with the groove of the connecting

rod or connecting cap.

(b) Install the bearings in the connecting rod and

connecting rod cap.

–

ENGINE MECHANICAL

Cylinder Block

EM–155

ASSEMBLY OF CYLINDER BLOCK

(See Components on page

EM–131

)

HINT:

•

Thoroughly clean all parts to be assembled.

•

Before installing the parts, apply new engine oil to all
sliding and rotating surfaces.

•

Replace all gaskets, O–rings and oil seals with new
parts.

1.

INSTALL MAIN BEARINGS
HINT:

•

Main bearings come in widths of 19.5 mm (0.768 in.) and
22.5 mm (0.886 in.). Install the 22.5 mm (0.886 in.)
bearings in the No.1 and No.5 cylinder block journal
positions with the main bearing caps. Install the 19.5
mm (0.768 in.) bearings in the other positions.

•

Upper bearings have an oil groove and oil holes; lower
bearings do not.

(a) Align

the

bearing

claw

with

the

claw

groove of

the

cylinder block, and push in the five upper bearings.

(b) Align the bearing claw with the claw groove of the main

bearing cap, and push in the five lower bearings.

HINT: A number is marked on each main bearing cap indicat-
ing the installation position.

2.

INSTALL UPPER THRUST WASHERS
Install the two thrust washers under the No.3 journal position
of the block with the oil grooves facing outward.

EM–156

–

ENGINE MECHANICAL

Cylinder Block

3.

PLACE CRANKSHAFT ON CYLINDER BLOCK

4. INSTALL MAIN BEARING CAP AND LOWER THRUST

WASHERS

A.

Place main bearing cap and lower thrust washers on cyl-
inder block
(a) Install the two thrust washers on the No.3 main bearing

cap with the grooves facing outward.

(b) Install the main bearing caps in their proper location.

(c) Place the five bearing caps in position on cylinder block.
HINT: Place the bearing caps level and let them return to their
original position by their own weight.
NOTICE: Do not install the main bearing cap by tapping
it.

B.

Install main bearing cap nuts
HINT:

•

The main bearing cap nuts are tightened in two
progressive steps (steps (b) and (d)).

•

If any one of the main bearing cap stud bolts is broken
or deformed, replace it.

(a) Apply

a

light coat of engine oil on the threads and under

the nuts of the main bearing caps.

(b) Install

and uniformly tighten the twenty main bearing cap

nuts in several passes in the sequence shown.

Torque: 27 N

⋅

m (275 kgf

⋅

cm, 20 ft

⋅

lbf)

If any one of the main bearing cap nuts does not meet the
torque specification, replace the main bearing cap stud bolt.

–

ENGINE MECHANICAL

Cylinder Block

EM–157

(c) Mark the front of the main bearing cap nut with paint.

(d) Retighten the main bearing cap nuts 905 in the

numerical order shown.

(e) Check

that the painted mark is now at a 905 angle to the

front.

(f) Check that the crankshaft turns smoothly.
(g) Check the crankshaft thrust clearance.

(See step 5 on page

EM–138

)

C.

Install main bearing cap bolts
(a) Install a new seal washer to the main bearing cap bolt.
(b) Install the ten main bearing cap bolts.

Torque: 49 N

⋅

m (500 kgf

⋅

cm, 36 ft

⋅

lbf)

5.

INSTALL PISTON AND CONNECTING ROD ASSEMBLIES
Using a piston ring compressor, push the correctly numbered
piston and connecting rod assemblies into each cylinder with
the front mark of the piston facing forward.
NOTICE: The shape of the piston varies for the RH and LH
banks. The RH piston is marked with ”R”, the LH piston
with ”L”.

EM–158

–

ENGINE MECHANICAL

Cylinder Block