Removal and Installation
TIMING CHAIN
Removal and Installation
CAUTION:
- After removing timing chains, do not turn the crankshaft and camshaft separately or the valves will strike the pistons.
- When installing camshafts, chain tensioners, oil seals, or other sliding parts, lubricate contacting surfaces with new engine oil.
- Apply new engine oil to bolt threads and seat surfaces when installing camshaft sprockets, camshaft brackets, and crankshaft pulley.
REMOVAL
1.Remove front timing chain case. Refer to "Removal and Installation" Removal and Installation.
2.Remove the intake manifold collector. Refer to "Removal and Installation" Removal and Installation.
3.Remove the spark plugs. Refer to "Removal and Installation" Removal and Installation.
4.Place paint marks on the timing chain and sprockets to indicate the correct position of the components for installation.
5.Disconnect the camshaft position sensor harness connectors.
6.Remove the rocker covers. Refer to "Removal and Installation (LH)" Removal and Installation (LH)
7.Remove the timing chain tensioner (primary).
Revision: March 20122013 Infiniti JX
a.Pull lever down and release plunger stopper tab. Plunger stopper tab can be pushed up to release (coaxial structure with lever).
b.Insert stopper pin into timing chain tensioner (primary) body hole to hold lever, and keep the tab released. An Allen wrench [1.2
mm (0.047 in)] is used for a stopper pin as an example.
c.Insert plunger into tensioner body by pressing the slack guide.
d.Keep the slack guide pressed and hold it by pushing the stopper pin through the lever hole and body hole.
e.Remove the bolts and remove the timing chain tensioner (primary).
8.Remove internal chain guide, tension guide and slack guide.
NOTE:
Tension guide can be removed after removing timing chain (primary).
9.Remove timing chain (primary) and crankshaft sprocket.
CAUTION:
After removing timing chains, do not turn the crankshaft and camshaft separately or the valves will strike the pistons.
10.Remove timing chain (secondary) and camshaft sprockets as follows:
Revision: March 20122013 Infiniti JX
a.Attach a suitable stopper pin (B) to the bank 1 (A) and bank 2
(C) timing chain tensioners (secondary) (1).
NOTE:
- Use approximately 0.5 mm (0.02 in) diameter hard metal pin as a stopper pin.
- Removal of camshaft bracket (No. 1) is required prior to removing the timing chain tensioner (secondary).
b.Remove camshaft sprockets (INT and EXH) bolts.
- Secure the hexagonal portion of camshaft using a wrench to loosen bolts.
CAUTION:
Do not loosen bolts using anything other than the camshaft hexagonal portion. Do not apply tension to the timing chain.
c.Remove timing chain (secondary) together with camshaft sprockets.
- Turn camshaft slightly to keep the chain tight when removing the timing chain (secondary).
- Insert 0.5 mm (0.020 in) thick metal or resin plate between timing chain and timing chain tensioner plunger (guide) (E).
Remove timing chain (secondary) (2) together with camshaft sprockets with timing chain loose from guide groove.
CAUTION:
Be careful of plunger coming off when removing timing chain (secondary). The plunger of timing chain tensioner (secondary) moves during operation, which could cause the stopper pin to fall out.
- Bank 1 shown.
d.Camshaft sprocket (INT) is two-for-one structure of sprockets for timing chain (primary) and for timing chain (secondary).
CAUTION:
- Handle camshaft sprocket (INT) carefully to avoid any shock to camshaft sprocket.
- Do not disassemble. [Do not loosen bolts (A) as shown].
INSPECTION
Revision: March 20122013 Infiniti JX
Check for cracks and any excessive wear of the timing chain. Replace the timing chain as necessary.
INSTALLATION
NOTE:
This illustration shows the relationship between the mating mark on each timing chain and on the corresponding sprocket with the components installed.
1.Install timing chain tensioners (secondary) with a new O-ring and the stopper pin attached.
CAUTION:
Do not reuse O-ring.
2.Check that dowel pin (A) and crankshaft key (1) are located as shown. (No. 1 cylinder at compression TDC)
NOTE:
Though camshaft does not stop at the position as shown, for the placement of cam nose, it is generally accepted camshaft is placed in the same direction.
3.Install timing chain (secondary) and camshaft sprockets (INT and EXH) as follows:
CAUTION:
Mating marks between timing chain and sprockets slip easily. Confirm all mating mark positions repeatedly during the installation process.
Revision: March 20122013 Infiniti JX
a.Push plunger of timing chain tensioner (secondary) and keep it pressed in with stopper pin (A).
b.Install timing chain (secondary) (2) and camshaft sprockets [INT
(1) and EXH (3)].
NOTE:
Bank 1 shown (rear view).
- Align the mating marks on timing chain (secondary) (orange link) with the mating marks on camshaft sprockets (INT and
EXH), and install them.
- Align dowel pin on camshafts with the groove on sprockets, and install them.
- Tighten the bolts for the camshaft sprockets by hand enough to prevent the dowel pins from falling out of the grooves.
- It may be difficult to visually check the dislocation of mating marks during and after installation. To make the matching easier, make a mating mark (A) on the top of sprocket teeth and its extended line with paint.
4.After confirming the mating marks are aligned, tighten the camshaft sprocket bolts.
- Secure the camshaft using a wrench at the hexagonal portion to tighten the bolts.
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5.Pull stopper pins (B) out from timing chain tensioners (secondary) (1).
6.Install the crankshaft sprocket on the crankshaft.
- Make sure the mating marks on the crankshaft sprocket face the front of the engine.
7.Install the timing chain (primary).
- Install timing chain (primary) so the mating mark (punched) (B)
on camshaft sprocket (C) is aligned with the pink link (A) on the timing chain, while the mating mark (notched) (E) on the crankshaft sprocket (D) is aligned with the orange one (F) on the timing chain, as shown.
- When it is difficult to align mating marks of the timing chain (primary) with each sprocket, gradually turn the camshaft using a wrench on the hexagonal portion to align it with the mating marks.
- During alignment, be careful to prevent dislocation of mating mark alignments of the secondary timing chains.
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8.Install the internal chain guide (1) and slack guide (2).
CAUTION:
Do not over tighten slack guide mounting bolt (2). It is normal for a gap (A) to exist under the bolt seat when bolt is tightened to specification.
9.Install the timing chain tensioner (primary) with the following procedure:
a.Pull plunger stopper tab (A) up (or turn lever downward) so as to remove plunger stopper tab from the ratchet of plunger (D).
NOTE:
Plunger stopper tab and lever (C) are synchronized.
b.Push plunger into the inside of tensioner body.
c.Hold plunger in the fully compressed position by engaging plunger stopper tab with the tip of ratchet.
d.To secure lever, insert stopper pin (E) through hole of lever into tensioner body hole (B).
- The lever parts and the tab are synchronized. Therefore, the plunger will be secured under this condition.
NOTE:
Illustration shows the example of 1.2 mm (0.047 in) diameter thin screwdriver being used as the stopper pin.
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e.Install timing chain tensioner (primary) (1).
- Remove any dirt and foreign materials completely from the back and the mounting surfaces of timing chain tensioner (primary).
f.Pull out stopper pin (A) after installing, and then release plunger.
10.Reconfirm that the matching marks on the sprockets and the timing chain have not slipped out of alignment.
11.Install the front timing chain case. Refer to "Removal and Installation" Removal and Installation.
12.Install the rocker covers. Refer to "Removal and Installation (LH)" Removal and Installation (LH)
13.Install the spark plugs. Refer to "Removal and Installation" Removal and Installation.
14.Install the intake manifold collector. Refer to "Removal and Installation" Removal and Installation.
Revision: March 20122013 Infiniti JX