Lexus SC300 / Lexus SC400. Manual - part 568

(c)  Set the timing mark (one dot mark) of the camshaft

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

(d) Alternately 

loosen and remove the two bearing cap bolts

holding the intake camshaft side of the oil feed pipe to
the cylinder head.

(e)  Uniformly loosen and remove the eight bearing cap

bolts in several passes in the sequence shown.

(f)  Remove the oil feed pipe, four bearing caps and

exhaust camshaft.

B.

Remove intake camshaft from RH cylinder head
(a)  Remove the rear bearing cap.
(b)  Set the timing mark (one dot mark) of the camshaft drive

gear at approx. 455 angle by turning the hexagon
wrench head portion of the intake camshaft with a
wrench.

(c)  Uniformly loosen and remove the eight bearing cap

bolts in several passes in the sequence shown.

(d)  Remove the four bearing caps, oil seal and intake

camshaft.

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ENGINE MECHANICAL

Cylinder Heads

EM–71

C.

Remove exhaust camshaft from LH cylinder head
(a)  Bring the service bolt hole of the driven sub–gear

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

(b)  Secure the exhaust camshaft sub–gear to the driven

gear with a service bolt.

Recommended service bolt:

Thread diameter 6 mm
Thread pitch 1.0 mm
Bolt length 16–20 mm (0.63–0.79 in.)

HINT: When removing the camshaft, make certain that the
torsional spring force of the sub–gear has been eliminated by
the above operation.
(c)  Set the timing mark (two dot marks) of the camshaft

driven gear at approx. 155 angle by turning the hexagon
wrench head portion of the exhaust camshaft with a
wrench.

(d) Alternately 

loosen and remove the two bearing cap bolts

holding the intake camshaft side of the oil feed pipe to
the cylinder head.

(e)  Uniformly loosen and remove the eight bearing cap

bolts in several passes in the sequence shown.

(f)  Remove the oil feed pipe, four bearing caps and

exhaust camshaft.

D.

Remove intake camshaft from LH cylinder head
(a)  Remove the front bearing cap.
(b)  Set the timing mark (one dot mark) of the camshaft drive

gear at approx. 605 angle by turning the hexagon
wrench head portion of the intake camshaft with a
wrench.

EM–72

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ENGINE MECHANICAL

Cylinder Heads

(c)  Uniformly loosen and remove the eight bearing cap

bolts in several passes in the sequence shown.

(d)  Remove the four bearing caps, oil seal and intake

camshaft.

HINT: Arrange the bearing caps in correct order.

42.  DISASSEMBLE EXHAUST CAMSHAFTS

(a) Mount the hexagon wrench head portion  of the

camshaft in a vise.

NOTICE: Be careful not to damage the camshaft.

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

camshaft sub–gear.

(c)  Using a screwdriver, turn the sub–gear clockwise, and

remove the service bolt (B).

NOTICE: Be careful not to damage the camshaft.

(d)  Using snap ring pliers, remove the snap ring.

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ENGINE MECHANICAL

Cylinder Heads

EM–73

(e)  Remove the following parts:

(1)

Wave washer

(2)

Camshaft sub–gear

(3)

Camshaft gear spring

HINT: Arrange the camshaft sub–gears and gear springs (RH
side and LH side).

43.  REMOVE CIRCULAR PLUGS

Remove the two bolts, seal washers, bearing cap and circular
plug. Remove the two circular plugs.

HINT: Arrange the bearing caps (RH side and LH side).

44.  DISCONNECT MAIN OXYGEN SENSOR CONNECTORS

Disconnect the RH and LH oxygen sensor connector.

EM–74

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ENGINE MECHANICAL

Cylinder Heads