Lexus SC300 / Lexus SC400. Manual - part 574

(d)  Insert a service bolt (A) into the service hole of the

camshaft sub–gear.

(e)  Using a screwdriver, align the service holes and teeth of

the camshaft driven gear and sub–gear by turning
camshaft sub–gear clockwise, and install a service bolt
(B).

NOTICE: Be careful not to damage the camshaft.
(f)  Remove the service bolt (A).

7. INSTALL 

CAMSHAFTS

NOTICE: Since the thrust clearance of the camshaft is
small, the camshaft must be held level while it is being
installed. If the camshaft is not kept level, the portion of
the cylinder head receiving the shaft thrust may crack or
be damaged causing the camshaft to seize or break. To
avoid this, the following steps should be carried out.

A.

Install intake camshaft to RH cylinder head
(a)  Apply MP grease to the thrust portion of the camshaft.
(b)  Place the intake camshaft at 45

°

 angle of the timing

mark (one dot mark) on the cylinder head.

(c)  Remove any old packing (FIPG) material.
(d)  Apply seal packing to the bearing cap (mark ”I6”) as

shown.

Seal packing: Part No. 08826–00080 or equivalent

(e)  Install the front bearing cap (mark ”I6”) with the arrow

mark facing rearward.

HINT:

•

Installing the front bearing cap will determine the thrust
position of the camshaft.

•

Align the arrow marks at front and rear of the cylinder
head with the mark on the bearing cap.

–

ENGINE MECHANICAL

Cylinder Heads

EM–95

(f)  Install the other bearing caps in the sequence shown

with the arrow mark facing rearward.

HINT: Align the arrow marks at front and rear of the cylinder
head with the mark on the bearing cap.

(g) Apply 

a 

light coat of engine oil on the threads and under

the heads (A only) of the bearing cap bolts.

HINT: Do not apply engine oil under the heads of the bearing
cap bolts (B).
(h)  Install a new seal washer to the bearing cap bolt (B).

Install the eight bearing cap bolts as shown.

HINT:

•

Use bearing cap bolts 38 mm (1.50 in.) in length. The
bolts are black (A) or silver (B) in color. Install the two
silver bolts to the front bearing cap. Install the six black
bolts to the other positions.

•

After installing the oil feed pipe, install the two bolts to
the rear bearing cap as directed in step B (i).

(i) 

Uniformly tighten the eight bearing cap bolts in several
passes in the sequence shown.

Torque: 16 N

⋅

m (160 kgf

⋅

cm, 12 ft

⋅

lbf)

B.

Install exhaust camshaft to RH cylinder head
(a)  Set the timing mark (one dot mark) of the camshaft drive

gear at 105 angle by turning the hexagon wrench head
portion of the intake camshaft with a wrench.

(b)  Apply MP grease to the thrust portion of the exhaust

camshaft.

(c)  Align the timing marks (one dot mark) of the camshaft

drive and driven gears.

(d)  Place the exhaust camshaft on the cylinder head.

EM–96

–

ENGINE MECHANICAL

Cylinder Heads

(e) Check 

that the exhaust camshaft moves smoothly in the

thrust direction.

(f)  Install the rear bearing cap with the arrow mark facing

rearward.

HINT:

•

Installing the rear bearing cap will determine the thrust
position of the camshaft.

•

Align the arrow marks at front and rear of the cylinder
head with the mark on the bearing cap.

(g)  Install the other bearing caps in the sequence shown

with the arrow mark facing rearward.

HINT: Align the arrow marks at front and rear of the cylinder
head with the mark on the bearing cap.

(h) Apply 

a 

light coat of engine oil on the threads and under

the heads of the bearing cap bolts.

(i) 

Install the oil feed pipe and ten bolts.

HINT: Use bearing cap bolts 38 mm (1.50 in.) and 52 mm
(2.05 in.) in length. Use black colored 38 mm (1.50 in.) bolts.
Install the two 52 mm (2.05 in.) bolts in outside positions of
the oil pipe. Install the eight 38 mm (1.50 in.) bolts in the other
positions.

(j)  Uniformly tighten the eight bearing cap bolts on the

bearing caps of the exhaust camshaft in several passes
in the sequence shown.

Torque: 16 N

⋅

m (160 kgf

⋅

cm, 12 ft

⋅

lbf)

–

ENGINE MECHANICAL

Cylinder Heads

EM–97

(k)  Alternately tighten the two bearing cap bolts on the rear

bearing cap of the intake camshaft in several passes.

Torque: 16 N

⋅

m (160 kgf

⋅

cm, 12 ft

⋅

lbf)

(l)  Bring the service bolt installed in the driven subgear

upward by turning the hexagon wrench head portion of
the camshaft with a wrench.

(m)  Remove the service bolt.

C.

Install intake camshaft to LH cylinder head
(a)  Apply MP grease to the thrust portion of the camshaft.
(b)  Place the intake camshaft at 60

°

 angle of the timing

mark (one dot mark) on the cylinder head.

(c)  Remove any old packing (FIPG) material.
(d)  Apply seal packing to the bearing cap (mark ”I1”) as

shown.

Seal packing: Part No. 08826–00080 or equivalent

(e)  Install the front bearing cap (mark ”I1”) with the arrow

mark facing forward.

HINT:

•

Installing the front bearing cap will determine the thrust
position of the camshaft.

•

Align the arrow marks at front and rear of the cylinder
head with the mark on the bearing cap.

EM–98

–

ENGINE MECHANICAL

Cylinder Heads