Lexus SC300 / Lexus SC400. Manual — part 424

(e) If there is noticeable wear on the belt teeth, check the

timing cover for damage, correct gasket installation and
foreign material on the pulley teeth.

If necessary, replace the timing belt.

2.

INSPECT IDLER PULLEY
Check the turning smoothness of the idler pulley.
If necessary, replace the idler pulley.

3.

INSPECT DRIVE BELT TENSIONER
Check the turning smoothness of the tensioner.
If necessary, replace the tensioner.

4.

INSPECT TIMING BELT TENSIONER
(a) Visually check tensioner for oil leakage.
HINT: It is normal for a tensioner to show a small trance of oil
on the pushrod seal.
However, if there is an outright oil leak, the tensioner must be
replaced.

(b) Hold the tensioner with both hands, and push the push

rod firmly against the floor or wall to check that it doesn’t
move.

If the push rod moves, replace the tensioner.

EM–28

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ENGINE MECHANICAL

Timing Belt

(c) Measure the protrusion of the push rod from housing

end.

Protrusion: 7.7–10.5 mm (0.303–0.413 in.)

If the protrusion is not as specified, replace the tensioner.

INSTALLATION OF TIMING BELT

(See Components page EM–23)

1.

INSTALL CRANKSHAFT TIMING PULLEY
(a) Align the pulley set key with the key groove of the pulley.
(b) Slide on the timing pulley facing the flange side inward.

2.

INSTALL IDLER PULLEY
(a) Apply adhesive to two or three threads of the pivot bolt.
Adhesive: Part No. 08833–00080, THREE BOND 1344,

LOCTITE 242 or equivalent

(b) Using a 10 mm hexagon wrench, install the plate washer

and pulley with the pivot bolt.

Torque: 34 N

⋅

m (350 kgf

⋅

cm, 25 ft

⋅

lbf)

(c) Check that the pulley bracket moves smoothly.

3.

TEMPORARILY INSTALL TIMING BELT
NOTICE: The engine should be cold.
(a) Use the crankshaft pulley bolt to turn the crankshaft and

align the timing marks on the crankshaft timing pulley
and on the oil pump body.

(b) Remove any oil or water on the crankshaft timing pulley

and idler pulley, and keep them clean.

(c) Install

the timing belt on the crankshaft timing pulley and

idler pulley.

HINT (When re–using timing belt): Align the matchmarks of
the crankshaft timing pulley and timing belt, and install the
belt with the arrow pointing in the direction of engine revolu-
tion.

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ENGINE MECHANICAL

Timing Belt

EM–29

4. INSTALL

TIMING

BELT

GUIDE

Install the guide, facing the cup side outward.

5.

INSTALL NO. 1 TIMING BELT COVER
(a) Install the two gaskets to the timing belt cover.
(b) Install the timing belt cover with the five bolts.

6.

INSTALL CRANKSHAFT PULLEY
(a) Align the pulley set key with the key groove of the pulley,

and slide on the pulley.

(b) Using SST, install and torque the bolt.
SST 09213–54015 (09651–60855) and 09330–00021

Torque: 324 N

⋅

m (3,300 kgf

⋅

cm, 239 ft

⋅

lbf)

7.

INSTALL CAMSHAFT TIMING PULLEYS
(a) Align the camshaft knock pin with the groove on the

pulley, and slide on the timing pulley.

(b) Using SST to hold the pulley, torque the pulley bolt.
SST 09278–54012

Torque: 79 N

⋅

m (810 kgf

⋅

cm, 59 ft

⋅

lbf)

8. SET NO. 1 CYLINDER TO TDC/COMPRESSION

(a) Turn the crankshaft pulley, and align its groove with

timing mark ”0” of the No. 1 timing belt cover.

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ENGINE MECHANICAL

Timing Belt

(b) Turn the camshaft, and align the timing marks of the

camshaft timing pulleys and No. 4 timing belt cover.

SST 09278–54012

9.

INSTALL TIMING BELT
HINT (When re–using timing belt): Align the matchmarks of
the timing belt and camshaft timing pulleys.

(a) Remove any oil or water on the camshaft timing pulley,

and keep it clean.

(b) Install the timing belt, checking the tension between the

crankshaft timing pulley and exhaust camshaft timing
pulley.

10. SET TIMING BELT TENSIONER

(a) Using a press, slowly press in the push rod using

981–9,807N (100–1,000 kgf, 220–2,205 lbf) of
pressure.

(b) Align

the holes of the push rod and housing, pass a 1.50

mm hexagon wrench through the holes to keep the push
rod retracted.

(c) Release the press.

(d) Install the dust boot onto the tensioner.

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ENGINE MECHANICAL

Timing Belt

EM–31