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EM-46Revision: August 2007
CAMSHAFT
2004 QX56
8. Loosen camshaft sprocket bolts as shown and remove camshaft
sprockets.
CAUTION:
To avoid interference between valves and pistons, do not
turn crankshaft or camshaft with timing chain discon-
nected.
9. Remove front cover bolts.
10. Remove bolts in the reverse of order shown to remove camshaft
brackets.
Remove No. 1 camshaft bracket.
NOTE:
The bottom and front surface of bracket will be stuck because
of liquid gasket.
11. Remove camshaft.
12. Remove valve lifters if necessary.
Correctly identify location where each part is removed from.
Keep parts organized to avoid mixing them up.
KBIA2485E
KBIA2486E
KBIA2522E
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CAMSHAFT
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INSPECTION AFTER REMOVAL
Camshaft Runout
1. Put V block on precise flat work bench, and support No. 1 and
No. 5 journal of camshaft.
2. Set dial gauge vertically to No. 3 journal.
3. Turn camshaft to one direction with hands, and measure cam-
shaft runout on dial gauge.
1/2 of runout is bend.
If measurement exceeds specification, replace camshaft.
Camshaft Cam Height
Measure camshaft cam height.
If measurement is not within the specifications, replace cam-
shaft.
Camshaft Journal Clearance
Camshaft Journal Diameter
Measure diameter of camshaft journal.
Camshaft Bracket Inner Diameter
Tighten camshaft bracket bolt to specified torque.
Measure inner diameter of camshaft bracket.
Calculation of Camshaft Journal Clearance
(Journal clearance) = (camshaft bracket inner diameter) – (camshaft
journal diameter)
If measurement is not within specification, replace either or both
camshaft and cylinder head.
NOTE:
Inner diameter of camshaft bracket is manufactured together with cylinder head. Replace the whole cylin-
der head assembly.Camshaft runout : Less than 0.02 mm (0.0008 in)
EMK0641D
Standard cam height
(intake & exhaust): 44.465 - 44.655 mm
(1.7506 - 1.7581 in)
Cam wear limit
(intake & exhaust): 0.02 mm (0.0008 in)
PBIC0039E
Standard diameter : 25.953 - 25.970 mm
(1.0218 - 1.0224 in)
PBIC0040E
Standard : 26.000 - 26.021 mm (1.0236 - 1.0244 in)
Standard : 0.030 - 0.068 mm (0.0012 - 0.0027 in)
PBIC1645E
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EM-48Revision: August 2007
CAMSHAFT
2004 QX56
Camshaft End Play
Install dial gauge in thrust direction on front end of camshaft.
Measure end play when camshaft is moved forward/backward
(in direction to axis).
If measurement is not within specification, replace with new
camshaft and measure again.
If measurement is still not within specification, replace with new
cylinder head.
Measure the following parts if end play is outside the specified
value.
–Dimension "A" for camshaft No. 1 journal
–Dimension "B" for cylinder head No. 1 journal
If measurements are not within specification, replace camshaft
and/or cylinder head.
Camshaft Sprocket Runout
1. Install camshaft in cylinder head.
2. Install camshaft sprocket to camshaft.
3. Measure camshaft sprocket runout.
If measurement exceeds the specification, replace camshaft
sprocket.
Valve Lifter
Check if surface of valve lifter has any wear or cracks.
If any damage is found, replace valve lifter.
Select the thickness of the head so that valve clearance is within
the standard when replacing. Refer to EM-52, "
Valve Clearance"
.Standard : 0.115 - 0.188 mm (0.0045 - 0.0074 in)
PBIC0042E
Standard : 30.500 - 30.548 mm (1.2008-1.2027 in)
Standard : 30.360 - 30.385 mm (1.1953-1.1963 in)
KBIA2426J
Runout : Less than 0.15 mm (0.0059 in)
KBIA0181J
KBIA0182E
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CAMSHAFT
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Valve Lifter Clearance
Valve Lifter Diameter
Measure diameter of valve lifter using suitable tool.
Valve Lifter Hole Diameter
Measure diameter of valve lifter hole of cylinder head using suit-
able tool.
Calculation of Valve Lifter Clearance
(Valve lifter clearance) = (valve lifter hole diameter) – (valve lifter
diameter)
If measurement is not within specification, referring to each
specification of valve lifter diameter and hole diameter, replace
either or both valve lifter and cylinder head.
INSTALLATION
1. Install valve lifters if removed.
Install removed parts in their original locations.
2. Install camshafts. Refer to the table below for identification of
right and left bank, and intake and exhaust.
Install so that dowel pin at the front of camshaft face is in the
direction shown.Standard : 33.977 - 33.987 mm (1.3377 - 1.3381 in)
JEM798G
Standard : 34.000 - 34.016 mm (1.3386 - 1.3392 in)
Standard : 0.013 - 0.039 mm (0.0005 - 0.0015 in)
PBIC0043E
Bank INT EXHIdentification
paint (front)Identification
paint (rear)Identification
rib
RHINT White — Yes.
EXH — Light blue Yes.
LHINT White — No.
EXH — Light blue No.
KBIA2523E
KBIA2524E
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EM-50Revision: August 2007
CAMSHAFT
2004 QX56
3. Install camshaft brackets.
Install by referring to installation location mark on upper sur-
face.
Install so that installation location mark can be correctly read
when viewed from the intake manifold side.
Install No.1 camshaft bracket using the following procedure:
–Apply liquid gasket to No.1 camshaft bracket as shown.
Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-45, "
Recommended Chemical Products and Sealants".
CAUTION:
After installation, be sure to wipe off any excessive liq-
uid gasket leaking from part “A” and “B” (both on right
and left sides).
Remove completely any excess of liquid gasket inside
bracket.
–Apply liquid gasket to the back side of front cover as shown.
Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-45, "
Recommended Chemical Products and Sealants".
–Position No.1 camshaft bracket close to mounting position,
and then install it to prevent from touching liquid gasket
applied to each surface.
KBIA2525E
PBIC0035E
KBIA2487E
SBIA0259E
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CAMSHAFT
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–Temporarily tighten front cover bolts (4 for each bank) as
shown.
4. Tighten camshaft bracket bolts as follows:
CAUTION:
After tightening camshaft bracket bolts, be sure to wipe off
excessive liquid gasket from the parts listed below.
Mating surface of rocker cover
Mating surface of front cover
a. Tighten front cover bolts (4 for each bank) as shown to the spec-
ified torque.
5. Install camshaft sprocket with the following procedure:
a. Install camshaft sprocket aligning with matching marks painted
on timing chain when removed. Align camshaft sprocket key
groove with dowel pin on camshaft front edge at the same time,
and then temporarily tighten bolts.
KBIA2486E
Camshaft bracket bolts
Step 1 (bolts 9 - 12) : 1.96 N·m (0.2 kg-m, 17 in-lb)
Step 2 (bolts 1 - 8) : 1.96 N·m (0.2 kg-m, 17 in-lb)
Step 3 (all bolts) : 5.88 N·m (0.6 kg-m, 52 in-lb)
Step 4 (all bolts) : 10.4 N·m (1.1 kg-m, 92 in-lb)
KBIA2522E
Front cover bolts : 11.0 N·m (1.1 kg-m, 8ft - lb)
KBIA2486E
KBIA2482E
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EM-52Revision: August 2007
CAMSHAFT
2004 QX56
Install intake and exhaust side camshaft sprocket by selec-
tively using the groove of dowel pin according to the bank.
(Common part used for both banks.)
b. Lock the hexagonal part of camshaft in the same way as for
removal, and tighten bolts.
c. Check again that the timing mating mark on timing chain and on
each sprocket are aligned.
6. Install chain tensioner with the following procedure:
NOTE:
Left bank is shown.
a. Install chain tensioner.
Compress plunger and hold it with a stopper pin when install-
ing.
Loosen the slack guide side timing chain by rotating camshaft
hexagonal part if mounting space is small.
b. Remove stopper pin and release plunger, and then apply ten-
sion to timing chain.
c. Install chain tensioner cover onto front cover. (RH bank)
Apply liquid gasket as shown.
Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-45, "
Recommended Chemical Products and Seal-
ants" .
7. Check and adjust valve clearances. Refer to EM-52, "
Va l v e
Clearance" .
8. Installation of the remaining components is in the reverse order
of removal.
Va lv e C le a ra n c eEBS00ILO
INSPECTION
NOTE:
Perform inspection as follows after removal, installation or replacement of camshaft or valve-related parts, or if
there are unusual engine conditions due to changes in valve clearance over time (starting, idling, and/or
noise).
1. Warm up engine. Then stop engine.
2. Remove engine cover, battery cover and air duct. Refer to EM-11, "
Removal and Installation" , SC-9,
"REMOVAL" and EM-14, "Removal and Installation" .
3. Remove right bank and left bank rocker covers using power tool. Refer to EM-33, "
Removal and Installa-
tion" .
KBIA2480E
Chain tensioner bolts : 6.9 N·m (0.70 kg-m, 61 in-lb)
Tensioner cover bolts : 9.0 N·m (0.92 kg-m, 80 in-lb)KBIA2479E
KBIA2547E
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CAMSHAFT
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4. Turn crankshaft pulley in normal direction (clockwise when
viewed from engine front) to align TDC identification notch (with-
out paint mark) with timing indicator.
5. At this time, make sure both the intake and exhaust cam noses
of No. 1 cylinder (top front on left bank) face outside.
If they do not face outside, turn crankshaft pulley once more.
6. Measure valve clearances at locations marked “×” as shown in
the table below (locations indicated with black arrow) using suit-
able tool.
NOTE:
Firing order 1-8-7-3-6-5-4-2
No. 1 cylinder compression TDC
Measure valve clearance using suitable tool.
KBIA2476E
KBIA0400J
Measuring position (RH bank) No. 2 CYL No. 4 CYL No. 6 CYL No. 8 CYL
No. 1 cylinder at TDC EXH ×
INT××
Measuring position (LH bank) No. 1 CYL No. 3 CYL No. 5 CYL No. 7 CYL
No. 1 cylinder at TDCINT××
EXH××
KBIA2526E
Valve clearance standard:
Hot*
Intake : 0.304 - 0.416 mm (0.012 - 0.016 in)
Exhaust : 0.308 - 0.432 mm (0.012 - 0.017 in)
Cold
Intake : 0.26 - 0.34 mm (0.010 - 0.013 in)
Exhaust : 0.29 - 0.37 mm (0.011 - 0.015 in)
* : Approximately 80°C (176°F)
KBIA0185E