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EM0281
P03976
P03977
−
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
−
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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P22567A16077
2 Dot Marks
EM−56
−
ENGINE MECHANICAL CYLINDER HEAD
1996 LAND CRUISER (RM451U)
(a) Install the intake camshaft.
(1) Apply engine oil to the thrust portion of the intakecamshaft.
(2) Lightly place the intake camshaft on top of the cylin-
der head as shown in the illustration so that the No.
1 and No. 4 cylinder cam lobes face downward.
(3) Lightly push the camshaft towards the front without
applying excessive force.
(4) Place the No. 2 and No. 5 bearing caps in their prop-
er location.
(5) Temporarily tighten these bearing cap bolts uni- formly and alternately in several passes until the
bearing caps are snug with the cylinder head.
(6) Place the No. 3, No. 4, No. 6 and No. 7 bearing caps
in their proper location.
(7) Temporarily tighten these bearing cap bolts, alter- nately tightening the left and right bolts uniformly.
(8) Place the No. 1 bearing cap in its proper location. When doing this, check that there is no gap be-
tween the cylinder head and the contact surface of
bearing cap.
(9) Temporarily tighten the bearing cap bolts, alternate-
ly tightening the left and right bolts uniformly.
(10) Uniformly tighten the 14 bearing cap bolts in several
passes.
Torque: 16 N·m (160 kgf·cm, 12 ft·lbf)
(b) Install the exhaust camshaft. (1) Set the timing mark (2 dot marks) of the camshaftdrive gear at approx. 35 ° angle by turning the hexa-
gon wrench head portion of the intake camshaft
with a wrench.
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−
ENGINE MECHANICAL CYLINDER HEAD
EM−57
1996 LAND CRUISER (RM451U)
(2) Apply engine oil to thrust portion of the exhaust
camshaft.
(3) Engage the exhaust camshaft gear to the intake
camshaft gear by matching the timing marks (two
dot marks) on each gear.
(4) Roll down the exhaust camshaft onto the bearing journals while engaging gears with each other.
(5) Lightly push the intake camshaft towards the front without applying excessive force.
(6) Install the No. 4 and No. 6 bearing caps in their proper location.
(7) Temporarily tighten the bearing cap bolts uniformly and alternately in several passes until the bearing
caps are snug with the cylinder head.
(8) Place the No. 2, No. 3, No. 5 and No. 7 bearing caps
in their proper location.
(9) Temporarily tighten these bearing cap bolts, alter- nately tightening the left and right bolts uniformly.
(10) Place the No. 1 bearing cap in its proper location. When doing this, check that there is no gap be-
tween the cylinder head and the contact surface of
bearing cap.
(11) Temporarily tighten the bearing cap bolts, alternate-
ly tightening the left and right bolts uniformly.
(12) Uniformly tighten the 14 bearing cap bolts in several
passes.
Torque: 16 N·m (160 kgf·cm, 12 ft·lbf)
(13) Bring the service bolt installed in the driven sub −
gear upward by turning the hexagon wrench head
portion of the camshaft with a wrench.
(14) Remove the service bolt.
(15) Check that the intake and exhaust camshafts turn smoothly.
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−
ENGINE MECHANICAL CYLINDER BLOCK
EM−85
1996 LAND CRUISER (RM451U)
14. REMOVE CONNECTING ROD CAPS AND CHECK OIL
CLEARANCE
(a) Check the matchmarks on the connecting rod cap and
connecting rod to ensure correct reassembly.
(b) Remove the connecting rod cap nuts.
(c) Using a plastic− faced hammer, lightly tap the connecting
rod bolts and lift off the connecting rod cap.
HINT:
Keep the lower bearing inserted with the connecting rod cap.
(d) Cover the connecting rod bolts with a short piece of hose to protect the crankshaft from damage.
(e) Clean the crank pin and bearing.
(f) Check the crank pin and bearing for pitting and scratches.
If the crank pin or bearing is damaged, replace the bearings. If
necessary, grind or replace the crankshaft.
(g) Lay a strip of Plastigage across the crank pin.
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EXAMPLE: Connecting rod ”3” + Crankshaft ”1”= Total number 4 (Use bearing ”4”)
Number marked
Connecting rod
Crankshaft
Use bearing 123
2
2 22
3
3 3
3 3
4445 56
111
EM−86
−
ENGINE MECHANICAL CYLINDER BLOCK
1996 LAND CRUISER (RM451U)
(h) Install the connecting rod cap with the 2 nuts (See page EM−103 ).
NOTICE:
Do not turn the crankshaft.
(i) Remove the 2 nuts and connecting rod cap (See proce-
dure (b) and (c) above).
(j) Measure the Plastigage at its widest point. Standard oil clearance:
STD0.032 − 0.050 mm (0.0013 − 0.0020 in.)
U/S 0.250.033 − 0.073 mm (0.0013 − 0.0029 in.)
Maximum oil clearance: 0.10 mm (0.0039 in.)
If the oil clearance is greater than maximum, replace the bear-
ings. If necessary, grind or replace the crankshaft.
HINT:
If using a standard bearing, replace with one having the same
number. If the number of the bearing cannot be determined, se-
lect the correct bearing by adding together the numbers im-
printed on the connecting rod and crankshaft, then selecting
the bearing with the same number as the total. There are 5 sizes
of standard bearings, marked ”2”, ”3”, ”4”, ”5” and ”6” according-
ly.
Reference
Connecting rod big end inside diameter:
Mark ”1”60.526 − 60.532 mm (2.3829 − 2.3831 in.)
Mark ”2”60.532 − 60.538 mm (2.3831 − 2.3834 in.)
Mark ”3”60.538 − 60.544 mm (2.3834 − 2.3836 in.)
Crankshaft crank pin diameter:
Mark ”1”56.994 − 57.000 mm (2.2439 − 2.2441 in.)
Mark ”2”56.988 − 56.994 mm (2.2436 − 2.2439 in.)
Mark ”3”56.982 − 56.988 mm (2.2434 − 2.2436 in.)
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P04620
−
ENGINE MECHANICAL CYLINDER BLOCK
EM−87
1996 LAND CRUISER (RM451U)
Standard sized bearing center wall thickness:
Mark ”2”1.744 − 1.747 mm (0.0687 − 0.0688 in.)
Mark ”3”1.747 − 1.750 mm (0.0688 − 0.0689 in.)
Mark ”4”1.750 − 1.753 mm (0.0689 − 0.0690 in.)
Mark ”5”1.753 − 1.756 mm (0.0690 − 0.0691 in.)
Mark ”6”1.756 − 1.759 mm (0.0691 − 0.0693 in.)
(k) Completely remove the Plastigage.
15. R E M O V E P I S TO N A N D C O N N E C T I N G R O D A S-
SEMBLIES
(a) Using a ridge reamer, remove the all carbon from the top of the cylinder.
(b) Push the piston, connecting rod assembly and upper bearing through the top of the cylinder block.
HINT:
Keep the bearings, connecting rod and cap together.
Arrange the piston and connecting rod assemblies in cor-
rect order.
16. CHECK CRANKSHAFT THRUST CLEARANCE
Using a dial indicator, measure the thrust clearance while prying
the crankshaft back and forth with a screwdriver. Standard thrust clearance:
0.020 − 0.220 mm (0.0008 − 0.0087 in.)
Maximum thrust clearance: 0.30 mm (0.0118 in.)
If the thrust clearance is greater than maximum, replace the
thrust washers as a set. Thrust washer thickness:
STD2.440 − 2.490 mm (0.0961 − 0.0980 in.)
O/S 0.1252.503 − 2.553 mm (0.0985 − 0.1005 in.)
O/S 0.2502.565 − 2.615 mm (0.1010 − 0.1030 in.)
17. REMOVE MAIN BEARING CAPS AND CHECK OIL
CLEARANCE
(a) Uniformly loosen and remove the main bearing cap bolts
in several passes, in the sequence shown.
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EM−88
−
ENGINE MECHANICAL CYLINDER BLOCK
1996 LAND CRUISER (RM451U)
(b) Using the removed main bearing cap bolts, pry the main
bearing cap back and forth, and remove the main bearing
caps, lower bearings and (No.4 main bearing cap only)
lower thrust washers.
HINT:
Keep the lower bearing and main bearing cap together.
Arrange the main bearing caps and lower thrust washers
in correct order.
(c) Lift out the crankshaft.
HINT:
Keep the upper bearing and upper thrust washers together with
the cylinder block.
(d) Clean each main journal and bearing.
(e) Check each main journal and bearing for pitting and
scratches.
If the journal or bearing is damaged, replace the bearings. If
necessary, grind or replace the crankshaft.
(f) Place the crankshaft on the cylinder block.
(g) Lay a strip of Plastigage across each journal.
(h) Install the main bearing caps (See page EM−103).
NOTICE:
Do not turn the crankshaft.
(i) Remove the main bearing caps (See procedure (a) and (b) above).
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