Page 814 of 1399
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ENGINE MECHANICAL CYLINDER HEAD
EM−29
1996 LAND CRUISER (RM451U)
16. DISCONNECT PS RESERVOIR TANK
Remove the 3 bolts and disconnect the reservoir tank.
17. DISCONNECT RADIATOR INLET HOSE
18. DISCONNECT NO. 3 WATER BYPASS HOSE
19. REMOVE GENERATOR (See page CH−8 )
20. REMOVE THROTTLE BODY (See page SF−45)
21. REMOVE OIL DIPSTICKS AND GUIDES FOR ENGINE AND TRANSMISSION
(a) Remove the 2 mounting bolts.
(b) Pull out the dipstick together with dipstick guide.
(c) Remove the O−ring from the dipstick guide.
22. REMOVE INTAKE MANIFOLD STAY
Remove the 2 bolts and intake manifold stay.
23. DISCONNECT FUEL INLET HOSE
Remove the union bolt and 2 gaskets, and disconnect the fuel
inlet hose from the fuel filter.
24. DISCONNECT ENGINE WIRE
(a) Disconnect the connectors. (1) Disconnect the ECT sender gauge connector.
(2) Disconnect the ECT cut switch connector.
(3) Disconnect the ECT sensor connector.
(4) Disconnect the knock sensor connector.
(5) Disconnect the crankshaft position sensor connec-tor.
(6) Remove the bolt and disconnect the engine wire from the cylinder block.
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Page 815 of 1399
EM−30
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ENGINE MECHANICAL CYLINDER HEAD
1996 LAND CRUISER (RM451U)
(b) Disconnect the connectors.
(1) Disconnect the knock sensor connector.
(2) Disconnect the oil level sensor connector.
(3) Disconnect the 2 connectors from the transmission.
(4) Disconnect the starter connector.
(c) Disconnect the 2 heated oxygen sensor connectors.
(d) Disconnect the PNP switch connector.
(e) Remove the 2 bolts and disconnect the engine wire from the intake manifold and cylinder block.
(f) Disconnect the PCV hose from the PCV valve.
(g) Remove the bolt holding the engine wire to the intake manifold.
(h) Disconnect the connectors. (1) Disconnect the connector for the emission controlvalve set assembly.
(2) Disconnect the 3 injector connectors.
(i) Disconnect the engine wire clamp.
(j) Disconnect the engine wire clamp.
(k) Disconnect the connectors.
(1) Disconnect the 3 injector connectors.
(2) Disconnect the EGR gas temp. sensor connector.
(l) Disconnect the clamp of the No. 6 injector wire from the bracket.
(m) Disconnect the engine wire from the cylinder head and in-
take manifold.
25. DISCONNECT NO. 2 WATER BYPASS PIPE
Remove the 3 bolts, and disconnect the bypass pipe from the
cylinder head.
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Page 823 of 1399
EM−38
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ENGINE MECHANICAL CYLINDER HEAD
1996 LAND CRUISER (RM451U)
8. REMOVE NO. 1 AND NO. 2 ENGINE HANGERS
9. REMOVE 2 ENGINE WIRE CLAMP BRACKETS
Remove the 2 bolts and 2 wire clamp brackets.
10. REMOVE ACCELERATOR CABLE BRACKET AND
THROTTLE CABLE BRACKET
Remove the 2 bolts and 2 cable brackets.
11. REMOVE VALVE LIFTERS AND SHIMS
HINT:
Arrange the valve lifters and shims in correct order.
12. REMOVE VALVES
(a) Using SST, compress the valve spring and remove the 2 keepers.
SST 09202−70020 (09202 −00010)
(b) Remove the spring retainer, valve spring and valve.
(c) Using needle −nose pliers, remove the oil seal.
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EM1Q7−01
EM−40
−
ENGINE MECHANICAL CYLINDER HEAD
1996 LAND CRUISER (RM451U)
INSPECTION
1. CLE AN TO P SURFACE S OF PIS TO NS AND CY L- INDER BLOCK
(a) Turn the crankshaft, and bring each piston to top dead center (TDC). Using a gasket scraper, remove all the car-
bon from the piston top surface.
(b) Using a gasket scraper, remove all the gasket material from the cylinder block surface.
(c) Using compressed air, blow carbon and oil from the bolt holes.
CAUTION:
Protect your eyes when using high −compressed air.
2. CLEAN CYLINDER HEAD
(a) Using a gasket scraper, remove all the gasket material from the cylinder block contact surface.
NOTICE:
Be careful not to scratch the cylinder block contact sur-
face.
(b) Using a wire brush, remove all the carbon from the com- bustion chambers.
NOTICE:
Be careful not to scratch the cylinder block contact sur-
face.
(c) Using a valve guide bushing brush and solvent, clean all the guide bushings.
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Page 827 of 1399
Z00054
44.5°
EM0181
Margin Thickness
EM−42
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ENGINE MECHANICAL CYLINDER HEAD
1996 LAND CRUISER (RM451U)
5. INSPECT VALVE STEMS AND GUIDE BUSHINGS
(a) Using a cali per gauge, measure the inside diameter of the
guide bushing.
Bushing inside diameter:
7.010 − 7.030 mm (0.2760 − 0.2768 in.)
(b) Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter:
Intake6.970 − 6.985 mm (0.2744 − 0.2750 in.)
Exhaust6.965 − 6.980 mm (0.2742 − 0.2748 in.)
(c) Subtract the valve stem diameter measurement from the
guide bushing inside diameter measurement.
Standard oil clearance:
Intake0.025 − 0.060 mm (0.0010 − 0.0024 in.)
Exhaust0.030 − 0.065 mm (0.0012 − 0.0026 in.)
Maximum oil clearance:
Intake0.08 mm (0.0031 in.)
Exhaust0.10 mm (0.0039 in.)
If the clearance is greater than maximum, replace the valve and
guide bushing (See page EM−49).
6. INSPECT AND GRIND VALVES
(a) Grind the valve enough to remove pits and carbon.
(b) Check that the valve is ground to the correct valve face angle.
Valve face angle: 44.5°
(c) Check the valve head margin thickness. Margin thickness:
Standard1.2 mm (0.047 in.)
Minimum1.0 mm (0.039 in.)
If the margin thickness is less than minimum, replace the valve.
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EM0281
P03976
P03977
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ENGINE MECHANICAL CYLINDER HEAD
EM−45
1996 LAND CRUISER (RM451U)
(c) Using a spring tester, measure the tension of the valve
spring at the specified installed length.
Installed tension:
214 − 238 N (21.8 − 24.2 kgf, 48.1 − 53.4 lbf)
at 36.5 mm (1.437 in.)
If the installed tension is not as specified, replace the valve
spring.
9. INSPECT CAMSHAFTS
(a) Inspect for runout. (1) Place the camshaft on V−blocks.
(2) Using a dial indicator, measure the circle runout atthe center journal.
Maximum circle runout: 0.06 mm (0.0024 in.)
If the circle runout is greater than maximum, replace the cam-
shaft.
(b) Inspect the cam lobes. Using a micrometer, measure the cam lobe height.
Standard cam lobe height:
50.61 − 50.71 mm (1.9925 − 1.9965 in.)
Minimum cam lobe height: 50.51 mm (1.9886 in.)
If the cam lobe height is less than minimum, replace the cam-
shaft.
(c) Inspect the journals. Using a micrometer, measure the journal diameter.
Journal diameter:
26.959 − 26.975 mm (1.0614 − 1.0620 in.)
If the journal diameter is not as specified, check the oil clear-
ance.
(d) Inspect the 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.
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EM3322
EM−46
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ENGINE MECHANICAL CYLINDER HEAD
1996 LAND CRUISER (RM451U)
(e) Inspect the gear spring
Using vernier calipers, measure the free distance be-
tween the spring ends.
Free distance: 18.2 − 18.8 mm (0.717 − 0.740 in.)
If the free distance is not as specified, replace the gear spring.
(f) Inspect the journal oil clearance. (1) Clean the bearing caps and camshaft journals.
(2) Place the camshafts on the cylinder head.
(3) Lay a strip of Plastigage across each of the cam-
shaft journals.
(4) Install the bearing caps (See page EM−54).
NOTICE:
Do not turn the camshaft. (5) Remove the bearing caps.
(6) Measure the Plastigage at its widest point.
Standard oil clearance:
0.025 − 0.062 mm (0.0010 − 0.0024 in.)
Maximum oil clearance: 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. (7) Completely remove the Plastigage.
(g) Inspect the thrust clearance. (1) Install the camshaft (See page EM−54 ).
(2) Using a dial indicator, measure the thrust clearance
while moving the camshaft back and forth.
Standard thrust clearance:
0.030 − 0.080 mm (0.0012 − 0.0031 in.)
Maximum thrust clearance: 0.10 mm (0.0039 in.)
If the thrust clearance is greater than maximum, replace the
camshaft. If necessary, replace the bearing caps and cylinder
head as a set.
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EM2196
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ENGINE MECHANICAL CYLINDER HEAD
EM−47
1996 LAND CRUISER (RM451U)
(h) Inspect the gear backlash.
(1) Install the camshafts without installing the exhaustcam sub−gear (See page EM−54).
(2) Using a dial indicator, measure the backlash.
Standard backlash:
0.020 − 0.200 mm (0.0008 − 0.0079 in.)
Maximum backlash: 0.30 mm (0.0188 in.)
If the backlash is greater than maximum, replace the cam-
shafts.
10. INSPECT VALVE LIFTER OIL CLEARANCE
(a) Using a caliper gauge, measure the lifter bore diameter of the cylinder head.
Lifter bore diameter:
34.000 − 34.021 mm (1.3386 − 1.3394 in.)
(b) Using a micrometer, measure the lifter diameter. Lifter diameter:
33.966 − 33.976 mm (1.3372 − 1.3376 in.)
(c) Subtract the lifter diameter measurement from the lifter bore diameter measurement.
Standard oil clearance:
0.024 − 0.055 mm (0.0009 − 0.0022 in.)
Maximum oil clearance: 0.07 mm (0.0028 in.)
If the oil clearance is greater than maximum, replace the lifter.
If necessary, replace the cylinder head.
11. INSPECT AIR INTAKE CHAMBER
Using a precision straight edge and thickness gauge, measure
the surface contacting the intake manifold for warpage. Maximum warpage: 0.30 mm (0.0118 in.)
If warpage is greater than maximum, replace the air intake
chamber.
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