Toyota Sequoia (2005). Manual - part 660

Z03988

45

°

30

°

1.0 – 1.4 mm

Z03989

60

°

45

°

1.0 – 1.4 mm

EM6331

EM0988

Deviation

EM–50

–

ENGINE MECHANICAL

CYLINDER HEAD

2629

(c)

Check the valve face and seat for the following:

If blue appears 360

°

 around the face, the valve is

concentric. If not, replace the valve.

If blue appears 360

°

 around the valve seat, the

guide and face are concentric. If not, resurface the
seat.

Check that the seat contact is in the middle of the
valve face with the following width:

1.0 to 1.4 mm (0.039 to 0.055 in.)

If not, correct the valve seats as follows:

If the seating is too high on the valve face, use 30

°

and 45

°

 cutters to correct the seat.

If the seating is too low on the valve face, use 60

°

and 45

°

 cutters to correct the seat.

(d)

Hand–lap the valve and valve seat with an abrasive com-
pound.

(e)

After hand–lapping, clean the valve and valve seat.

13.

INSPECT VALVE SPRINGS

(a)

Using a steel square, measure the deviation of the valve
spring.
Maximum deviation: 2.0 mm (0.079 in.)

If the deviation is greater than maximum, replace the valve
spring.

EM0801

EM0281

A05912

EM2011

–

ENGINE MECHANICAL

CYLINDER HEAD

EM–51

2630

(b)

Using vernier calipers, measure the free length of the
valve spring.
Free length: 54.1 mm (2.130 in.)

If the free length is not as specified, replace the valve spring.

(c)

Using a spring tester, measure the tension of the valve
spring at the specified installed length.
Installed tension:
210 to 226 N (21.4 to 23.0 kgf, 47.2 to 50.7 lbf)
at 35.0 mm (1.378 in.)

If the installed tension is not as specified, replace the valve
spring.

14.

INSPECT CAMSHAFT FOR RUNOUT

(a)

Place the camshaft on V–blocks.

(b)

Using a dial indicator, measure the circle runout at the
center journal.
Maximum circle runout: 0.03 mm (0.0012 in.)

If the circle runout is greater than maximum, replace the cam-
shaft.

15.

INSPECT CAM LOBES

Using a micrometer, measure the cam lobe height.

Standard cam lobe height:

Intake

42.61 to 42.71 mm (1.6776 to 1.6815 in.)

Exhaust

42.63 to 42.73 mm (1.6783 to 1.6823 in.)

Minimum cam lobe height:

Intake

42.46 mm (1.6717 in.)

Exhaust

42.48 mm (1.6724 in.)

If the cam lobe height is less than minimum, replace the cam-
shaft.

A04022

A23346

A23347

Turn

EM3322

A04083

Plastigage

EM–52

–

ENGINE MECHANICAL

CYLINDER HEAD

2631

16.

INSPECT CAMSHAFT JOURNALS

Using a micrometer, measure the journal diameter.

Journal diameter:
26.954 to 26.970 mm (1.0612 to 1.0618 in.)

If the journal diameter is not as specified, check the oil clear-
ance (see step 20).

17.

INSPECT CAMSHAFT TIMING TUBE

(a)

Using a micrometer, measure the journal diameter.
Journal diameter:
39.955 to 39.964 mm (1.5730 to 1.5734 in.)

If the journal diameter is not as specified, check the oil clear-
ance.

(b)

Install the timing tube to the intake camshaft, and check
the timing tube turns smoothly.

If necessary, replace the timing tube and intake camshaft.

18.

INSPECT CAMSHAFT GEAR SPRING

Using vernier calipers, measure the free distance between the
spring ends.

Free distance: 18.2 to 18.8 mm (0.717 to 0.740 in.)

If the free distance is not as specified, replace the gear spring.
19.

INSPECT CAMSHAFT BEARINGS

Check the bearings for flaking and scoring.
If the bearings are damaged, replace the bearing caps and cyl-
inder head as a set.

20.

INSPECT CAMSHAFT JOURNAL OIL CLEARANCE

(a)

Install the camshaft timing tube to the intake camshaft
(see page 

EM–58

).

(b)

Clean the bearing caps and camshaft journals.

(c)

Place the camshafts on the cylinder head.

(d)

Lay a strip of Plastigage across each of the camshaft jour-
nals.

A04099

A

A

A04084

A23348

–

ENGINE MECHANICAL

CYLINDER HEAD

EM–53

2632

(e)

Install the bearing caps (see page 

EM–60

).

Torque: 
7.5 N·m (76 kgf·cm, 66 in.·lbf) for bolt A
16 N·m (160 kgf·cm, 12 ft·lbf) for others

NOTICE:
Do not turn the camshaft.
(f)

Remove the bearing caps.

(g)

Measure the Plastigage at its widest point.
Standard oil clearance:

Camshaft journal

0.030 to 0.071 mm (0.0012 to 0.0028 in.)

Camshaft timing tube

journal

0.036 to 0.057 mm (0.0014 to 0.0022 in.)

Maximum oil clearance:

Camshaft journal

0.100 mm (0.0039 in.)

Camshaft timing tube

journal

0.075 mm (0.0030 in.)

If the oil clearance is greater than the maximum, replace the
camshaft. If necessary, replace the bearing caps and cylinder
head as a set.
(h)

Completely remove the Plastigage.

(i)

Remove the camshafts.

(j)

Remove the camshaft timing tube from the intake cam-
shaft.

21.

INSPECT CAMSHAFT THRUST CLEARANCE

(a)

Install the camshaft timing tube to the intake camshaft
(see page 

EM–58

).

(b)

Install the camshaft (see page 

EM–58

).

(c)

Using a dial indicator, measure the thrust clearance while
moving the camshaft back and forth.
Standard thrust clearance:

Intake

0 to 0.040 mm (0 to 0.0016 in.)

Exhaust

0.030 to 0.070 mm (0.0012 to 0.0028 in.)

Maximum thrust clearance:

Intake

0.12 mm (0.0047 in.)

Exhaust

0.10 mm (0.0039 in.)

If the thrust clearance is greater than the maximum, replace the
camshaft. If necessary, replace the bearing caps and cylinder
head as a set.
(d)

Remove the camshafts.

(e)

Remove the camshaft timing tube from the intake cam-
shaft.