INFINITI QX56 2006 Factory Service Manual

EM-50Revision: November 2009
CAMSHAFT
2006 QX56
INSPECTION AFTER REMOVAL
Camshaft Runout
1. Put V block on precise flat work bench, and support No. 1 andNo. 5 journals of the camshaft.
2. Set dial indicator vertically to No. 3 journal.
3. Turn the camshaft to one direction, and measure the camshaft runout on dial indicator (total indicator reading).

If measurement exceeds specification, replace the camshaft.
Camshaft Cam Height

Measure the camshaft cam height.

If measurement is not within the specifications, replace the cam-
shaft.
Camshaft Journal Clearance
Camshaft Journal Diameter

Measure the diameter of the camshaft journal.
Camshaft Bracket Inner Diameter

Tighten the camshaft bracket bolt to the specified torque.

Measure the inner diameter of the 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:
The inner diameter of the camshaft bracket is manufactured together with the cylinder head. Replace the
whole cylinder head as an 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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Camshaft End Play

Install dial gauge in the thrust direction on the front end of the
camshaft. Measure the end play when the camshaft is moved
forward/backward (in direction to axis).

If measurement is out of the specified range, replace the cam-
shaft and measure again.

If measurement is still out of the specified range, replace the cyl-
inder 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 the cam-
shaft and/or cylinder head.
Camshaft Sprocket Runout
1. Install the camshaft in the cylinder head.
2. Install the camshaft sprocket to the camshaft.
3. Measure the camshaft sprocket runout.

If measurement exceeds the specification, replace the cam-
shaft sprocket.
Valve Lifter
Check if the surface of the valve lifter has any wear or cracks.

If any damage is found, replace the valve lifter.

Select the thickness of the head so that the valve clearance is
within the standard when replacing. Refer to EM-55, "
Va l v e
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

EM-52Revision: November 2009
CAMSHAFT
2006 QX56
Valve Lifter Clearance
Valve Lifter Diameter

Measure the diameter of the valve lifter.
Valve Lifter Hole Diameter

Measure the diameter of the valve lifter hole of the cylinder
head, using suitable tool.
Calculation of Valve Lifter Clearance
(Valve lifter clearance) = (valve lifter hole diameter) – (valve lifter
diameter)

If the measurement is not within specification, referring to each
specification of the valve lifter diameter and hole diameter,
replace either or both the valve lifter and cylinder head.
INSTALLATION
1. Install the valve lifters if removed.

Install removed parts in their original locations.
2. Install the camshafts. Refer to the table below for identification of the RH and LH, and intake and exhaust.

Install so that the RH bank (B) dowel pins (A) and LH bank (C)
dowel pins (A) at the front of the camshaft face are 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 EXH
Identification
paint (front) Identification
paint (rear) Identification
rib
RH INT White
—Ye s
EXH —Light blue Yes
LH INT White
—No
EXH —Light blue No
KBIA2523E
WBIA0708E

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Revision: November 2009 2006 QX56
3. Install the RH bank (B) and LH bank (D) camshaft brackets.

Install by referring to the installation location mark (E) on the
upper surface.

Install so that the installation location mark (E) can be cor-
rectly read when viewed from the intake manifold side.

Install No. 1 camshaft bracket using the following procedure:

a:11 mm (0.43 in)

b: 2.0 - 3.0 mm (0.079 - 0.118 in) dia.
–Apply liquid gasket to No. 1 camshaft bracket as shown.
Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-46, "
Recommended Chemical Products and Sealants".
CAUTION:

After installation, be sure to wipe off any excessive liq-
uid gasket leaking from part (C) and (D) both on RH and
LH sides.

Remove completely any excess of liquid gasket inside
bracket.

a:2.6 - 3.6 mm (0.102 - 0.142 in) dia.
–Apply liquid gasket (C) to the back side of the LH (A) bank
front cover and RH (B) bank front cover as shown.
Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-46, "
Recommended Chemical Products and Sealants".
WBIA0709E
WBIA0710E
WBIA0711E

EM-54Revision: November 2009
CAMSHAFT
2006 QX56
–Position No. 1 camshaft bracket close to the mounting posi-
tion, and then install it to prevent from touching liquid gasket
applied to each surface.
–Temporarily tighten the front cover bolts (4 for each bank) as
shown.
4. Tighten the camshaft bracket bolts as follows: CAUTION:
After tightening the 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 the front cover bolts (4 for each bank) as shown to the specified torque.
SBIA0259E
WBIA0706E
Camshaft bracket bolts
Step 1 (bolts 9 - 12) : 2.0 N·m (0.2 kg-m, 17 in-lb)
Step 2 (bolts 1 - 8) : 2.0 N·m (0.2 kg-m, 17 in-lb)
Step 3 (all bolts) : 5.9 N·m (0.6 kg-m, 52 in-lb)
Step 4 (all bolts) : 10.4 N·m (1.1 kg-m, 92 in-lb)
WBIA0707E
Front cover bolts : 11.0 N·m (1.1 kg-m, 8 ft-lb)
WBIA0706E

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Revision: November 2009 2006 QX56
5. Install the camshaft sprockets using the following procedure:

A: LH bank shown
a. Install the camshaft sprockets aligning them with the matching marks painted (B) on the timing chain (C) when removed. Align
the camshaft sprocket key groove with the dowel pin on the
camshaft front edge at the same time. Then temporarily tighten
camshaft sprocket bolts.

Install the intake and exhaust side camshaft sprockets by
selectively using the groove of the dowel pin according to the
bank. (Common part used for both banks.)

A: Intake (I)

B: Exhaust (E)

R: for RH bank

L: for LH bank
b. Lock the hexagonal part of the camshaft in the same way as for removal, and tighten the camshaft sprocket bolts.
c. Check again that the timing alignment mark on the timing chain and on each sprocket are aligned.
6. Install the chain tensioner using the following procedure: NOTE:
LH is shown.
a. Install the chain tensioner.

Compress the plunger and hold it using a stopper pin when
installing.

Loosen the slack guide side timing chain by rotating the cam-
shaft hexagonal part if mounting space is small.
b. Remove the stopper pin and release the plunger, and then apply tension to the timing chain.
c. Install the RH bank timing chain tensioner cover onto the front cover.

Apply liquid gasket as shown.
Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-46, "
Recommended Chemical Products and Sealants"
.
7. Check and adjust valve clearances. Refer to EM-55, "
Va l v e
Clearance" .
8. Installation of the remaining components is in the reverse order of removal.
Va l v e C l e a r a n c eEBS00RF9
INSPECTION
NOTE:
Perform the following inspection 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).
WBIA0712E
WBIA0700E
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

EM-56Revision: November 2009
CAMSHAFT
2006 QX56
1. Warm up the engine. Then stop the engine.
2. Remove the engine cover and. Refer to EM-12, "
Removal and Installation" .
3. Remove the battery cover. Refer to SC-9, "
Removal and Installation" .
4. Remove the air cleaner and air duct assembly EM-15, "
Removal and Installation" .
5. Remove the RH bank and LH bank rocker covers using power tool. Refer to EM-35, "
REMOVAL" .
6. Turn the crankshaft pulley in the normal direction (clockwise when viewed from engine front) to align TDC identification notch
(without paint mark) with timing indicator.
7. At this time, make sure both the intake and exhaust cam noses of No. 1 cylinder (top front on LH bank) face outside.

If they do not face outside, turn crankshaft pulley once more.
8. Measure valve clearances at the locations marked “×” as shown
in the table below (locations indicated with black arrow).

⇐ : Engine front

⇐ (black): Measurable at No.1 cylinder compression top dead
center

⇐ (white): Measurable at No. 3 cylinder compression top
dead center

A: RH

B: LH

C: Exhaust

D: Intake
NOTE:
Firing order 1-8-7-3-6-5-4-2

No. 1 cylinder compression TDC
KBIA2476E
KBIA0400J
Measuring position (RH bank) No. 2 cyl
(E) No. 4 cyl
(F) No. 6 cyl
(G) No. 8 cyl
(H)
No. 1 cylinder at TDC EXH
×
INT ××
Measuring position (LH bank) No. 1 cyl
(J) No. 3 cyl
(K) No. 5 cyl
(L) No. 7 cyl
(M)
No. 1 cylinder at TDC INT
××
EXH ××
WBIA0713E

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Measure valve clearance using suitable tool.Refer to EM-105,
"Valve Clearance" .
CAUTION:
If the inspection was carried out with a cold engine, make
sure the values with a fully warmed up engine are still
within specifications.
9. Turn the crankshaft pulley clockwise 270 ° from the position of No. 1 cylinder compression TDC to obtain
No. 3 cylinder compression TDC.
10. Measure valve clearances at the locations marked “×” as shown
in the table below (locations indicated with white arrow).

⇐ : Engine front

⇐ (black): Measurable at No.1 cylinder compression top dead
center

⇐ (white): Measurable at No. 3 cylinder compression top
dead center

A: RH

B: LH

C: Exhaust

D: Intake
NOTE:
Firing order 1-8-7-2-3-6-5-4-2

No. 3 cylinder compression TDC

Measure valve clearance using suitable tool.Refer to EM-105,
"Valve Clearance" .
CAUTION:
If the inspection was carried out with a cold engine, make
sure the values with a fully warmed up engine are still
within specifications.
KBIA0185E
Measuring position (RH bank) No. 2 cyl
(E) No. 4 cyl
(F) No. 6 cyl
(G) No. 8 cyl
(H)
No. 3 cylinder at TDC EXH
×
INT ×
Measuring position (LH bank) No. 1 cyl
(J) No. 3 cyl
(K) No. 5 cyl
(L) No. 7 cyl
(M)
No. 3 cylinder at TDC INT
××
EXH ××
WBIA0713E
KBIA0185E

EM-58Revision: November 2009
CAMSHAFT
2006 QX56
11. Turn the crankshaft pulley clockwise 90° from the position of No.
3 cylinder compression TDC (clockwise by 360 ° from the posi-
tion of No. 1 cylinder compression TDC) to measure the intake
and exhaust valve clearances of No. 6 cylinder and the exhaust
valve clearance of No. 2 cylinder.
12. If out of specifications, adjust as necessary. Refer to EM-58, "
ADJUSTMENT" .
ADJUSTMENT
NOTE:

Perform adjustment depending on the selected head thickness of the valve lifter.

The specified valve lifter thickness is the dimension at normal temperatures. Ignore dimensional differ-
ences caused by temperature. Use the specifications for hot engine condition to adjust.
1. Remove the camshaft. Refer to EM-46, "
REMOVAL" .
2. Remove the valve lifters at the locations that are out of specification.
3. Measure the center thickness of the removed valve lifters using suitable tool.
4. Use the equation below to calculate the valve lifter thickness for replacement.

Valve lifter thickness calculation:
Thickness of replacement valve lifter = t1+ (C1 - C2)
t1 = Thickness of removed valve lifter
C1 = Measured valve clearance
C2= Standard valve clearance:

Thickness of a new valve lifter can be identified by stamp
marks on the reverse side (inside the cylinder).
Stamp mark N788 indicates 7.88 mm (0.3102 in) in thickness.

Available thickness of valve lifter: 25 sizes with range 7.88 to
8.36 mm (0.3102 to 0.3291 in) in steps of 0.02 mm (0.0008 in)
(when manufactured at factory). Refer to EM-106, "
Available
Valve Lifter" .
WBIA0713E
KBIA0057E
KBIA0119E

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Revision: November 2009 2006 QX56
5. Install the selected valve lifter.
6. Install the camshaft.
7. Manually turn the crankshaft pulley a few turns.
8. Make sure the valve clearances for a cold engine are within specifications by referring to the specified val-
ues.
9. After completing the repair, check the valve clearances again with the specifications for a warmed engine. Make sure the values are within specifications. Refer to EM-105, "
Valve Clearance" .