Lexus LS400 (2000 year). Service manual — part 90
Z03989
60
°
45
°
1.0 – 1.4 mm
EM6331
EM0988
Deviation
EM0801
EM0281
EM–48
–
ENGINE MECHANICAL
CYLINDER HEAD
1230
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.
12.
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.
(b)
Using vernier calipers, measure the free length of the
valve spring.
Free length: 54.05 – 54.15 mm (2.1279 – 2.1319 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:
204 – 226 N (20.8 – 23.0 kgf, 45.9 – 50.7 lbf)
at 35.0 mm (1.378 in.)
If the installed tension is not as specified, replace the valve
spring.
A03202
EM2011
EM2538
A02880
A03222
A
A
–
ENGINE MECHANICAL
CYLINDER HEAD
EM–49
1231
13.
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: 0.08 mm (0.0031 in.)
If the circle runout is greater than maximum, replace the cam-
shaft.
14.
INSPECT CAM LOBES
Using a micrometer, measure the cam lobe height.
Standard cam lobe height:
Intake
42.610 – 42.710 mm (1.6776 – 1.6815 in.)
Exhaust
42.630 – 42.730 mm (1.6783 – 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.
15.
INSPECT CAMSHAFT JOURNALS
Using a micrometer, measure the journal diameter.
Journal diameter:
Intake camshaft (A)
30.984 – 31.000 mm (1.2198 – 1.2205 in.)
Others
26.954 – 26.970 mm (1.0612 – 1.0618 in.)
If the journal diameter is not as specified, check the oil clear-
ance.
A03217
Knock Pin
Red Painted
Mark
Green
Painted
Mark
A03203
EM3322
A03216
LH Cylinder Head
RH Cylinder Head
Front
Mark
A or B
A03204
Plastigage
EM–50
–
ENGINE MECHANICAL
CYLINDER HEAD
1232
16.
INSPECT CAMSHAFT TIMING TUBE JOURNALS
HINT:
There are 2 size of the camshaft timing tube journal diameter,
green and red painted mark accordingly. The mark is painted
on the face of the camshaft timing tube.
Using a micrometer, measure the journal diameter.
Journal diameter:
Green painted mark
39.958 – 39.964 mm (1.5731 – 1.5734 in.)
Red painted mark
39.964 – 39.970 mm (1.5734 – 1.5736 in.)
If the journal diameter is not as specified, check the oil clear-
ance.
17.
INSPECT CAMSHAFT GEAR SPRING
Using vernier calipers, measure the free distance between the
spring ends.
Free distance: 18.2 – 18.8 mm (0.712 – 0.740 in.)
If the free distance is not as specified, replace the gear spring.
18.
INSPECT CAMSHAFT BEARINGS
Check that bearings for flaking and scoring.
If the bearings are damaged, replace the bearing caps and cyl-
inder head as a set.
19.
INSPECT CAMSHAFT TIMING TUBE AND CAMSHAFT
JOURNAL OIL CLEARANCE
HINT:
There are 2 size of the camshaft timing tube journal oil clear-
ance, Marked ”A” and ”B” accordingly. The mark is stamped on
the top of the cylinder heads.
(a)
Install the camshaft timing tube. (See page
(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.
A03205
A03206
A03207
–
ENGINE MECHANICAL
CYLINDER HEAD
EM–51
1233
(e)
Install the bearing caps. (See page
Torque: 16 N·m (160 kgf·cm, 12 ft·lbf)
NOTICE:
Do not turn the camshaft.
(f)
Remove the bearing caps.
(g)
Measure the Plastigage at its widest point.
Standard Oil clearance:
Camshaft timing tube
Mark ”A”
0.036 – 0.050 mm (0.0014 – 0.0020 in.)
Camshaft timing tube
Mark ”B”
0.038 – 0.052 mm (0.0015 – 0.0021 in.)
Others
0.030 – 0.067 mm (0.0012 – 0.0026 in.)
Maximum oil clearance:
Camshaft timing tube
0.085 mm (0.0033 in.)
Others
0.10 mm (0.0039 in.)
If the oil clearance is greater than maximum, replace the cam-
shaft. 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.
20.
IF NECESSARY REPLACE CAMSHAFT TIMING TUBE
Select a camshaft timing tube according to mark on the cylinder
head.
Cylinder Head
Camshaft timing tube
Mark ”A”
Green painted mark
Mark ”B”
Red painted mark
21.
INSPECT CAMSHAFT THRUST CLEARANCE
(a)
Install the camshaft timing tube. (See page
(b)
Install the camshaft. (See page
(c)
Using a dial indicator, measure the thrust clearance while
moving the camshaft back and forth.
Standard thrust clearance:
Intake
0.060 – 0.100 mm (0.0024 – 0.0039 in.)
Exhaust
0.040 – 0.090 mm (0.0016 – 0.0035 in.)
Maximum thrust clearance:
Intake
0.13 mm (0.0051 in.)
Exhaust
0.12 mm (0.0047 in.)
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст