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. Front Timing Chain Case.
2. Remove timing chain tensioner (primary) as follows:
a. Loosen clip of timing chain tensioner (primary), and release plunger stopper (1).
b. Insert plunger into tensioner body by pressing slack guide (2).
c. Keep slack guide pressed and hold plunger in by pushing stopper pin through the tensioner body hole and plunger groove (3).
d. Remove bolts and remove timing chain tensioner (primary).
3. Remove internal chain guide, tension guide and slack guide.
NOTE:
Tension guide can be removed after removing timing chain (primary).
4. Remove timing chain (primary).
CAUTION:
After removing timing chain (primary), do not turn crankshaft and camshaft separately, or valves will strike the piston heads.
5. Remove crankshaft sprocket, if necessary.
6. Remove RH and LH rocker covers. Removal And Installation.
7. Remove timing chain (secondary) and camshaft sprockets as follows:
a. Attach suitable stopper pin to the right and left timing chain tensioners (secondary).
NOTE:
- Use approximately 0.5 mm (0.02 in) dia. hard metal pin as a stopper pin.
- For removal of timing chain tensioner (secondary), Removal And Installation. [Removing camshaft bracket (No. 1) is required.]
b. Remove camshaft sprocket (INT and EXH) bolts.
- Secure the hexagonal portion of camshaft using wrench to loosen bolts.
CAUTION:
Do not loosen bolts by securing anything other than the camshaft hexagonal portion.
c. Remove timing chain (secondary) together with camshaft sprockets.
- Turn camshaft slightly to secure slackness of timing chain on timing chain tensioner (secondary) side.
- Insert 0.5 mm (0.020 in)-thick metal or resin plate between timing chain and timing chain tensioner plunger (guide). Remove timing chain (secondary) together with camshaft sprockets with timing chain loose from guide groove.
CAUTION:
Be careful of plunger coming off when removing timing chain (secondary).
NOTE:
Camshaft sprocket (INT) is a one piece integrated design sprockets for timing chain (primary) and for timing chain (secondary).
- When handling camshaft sprocket (INT), be careful of the following:
CAUTION:
- Handle carefully to avoid any shock to camshaft sprocket.
- Do not disassemble. (Do not loosen bolts (A) as shown).
8. Remove timing chain tensioners (secondary) from cylinder head if necessary.
a. Remove camshaft brackets (No. 1). Removal And Installation.
b. Remove timing chain tensioners (secondary) with stopper pin attached.
INSPECTION AFTER REMOVAL
Check for cracks and any excessive wear at link plates. Replace chain if necessary.
- In the same way as for the LH bank, inspect the timing chain and associated parts on the RH bank.
INSTALLATION
NOTE:
The figure above shows the relationship between the mating mark on each timing chain and that on the corresponding sprocket, with the components installed.
1. Install timing chain tensioners (secondary) to cylinder head if removed.
a. Install timing chain tensioners (secondary) with stopper pin attached and new O-ring.
b. Install camshaft brackets (No. 1). Removal And Installation.
2. Make sure that dowel pin hole, dowel pin of camshaft and crankshaft key 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 for the same direction of the figure.
CAUTION:
Hole on small dia. side must be used for intake side dowel pin hole. Do not misidentify (ignore big dia. side).
3. Install timing chains (secondary) and camshaft sprockets as follows:
CAUTION:
Mating marks between timing chain and sprockets slip easily. Confirm all mating mark positions repeatedly during the installation process.
a. Push plunger of timing chain tensioner (secondary) and keep it pressed in with stopper pin.
b. Install timing chains (secondary) (8) and camshaft sprockets
[INT (1) and EXH (9)].
- Left bank mating marks (6)
- Align the timing chain mating marks (secondary) (2) (blue color link) with the ones on camshaft sprockets (INT and EXH)
(4), (5), (7) and (10) (punched), and install them.
NOTE:
- Mating marks for camshaft sprocket (INT) are on the back side of camshaft sprocket (secondary).
- There are two types of mating marks, circle (7), (10) and oval (4), (5) types. They should be used for the right and left banks, respectively.
- Align dowel pin (3) and pin hole on camshafts with the groove
(11) and dowel pin on sprockets, and install them.
- On the intake side, align pin hole on the small diameter side of the camshaft front end with dowel pin (3) on the back side of camshaft sprocket, and install them.
- On the exhaust side, align dowel pin on camshaft front end with pin groove (11) on camshaft sprocket, and install them.
- In case that positions of each mating mark and each dowel pin do not fit on mating parts, make fine adjustment to the position holding the hexagonal portion on camshaft with wrench or equivalent.
- Bolts for camshaft sprockets must be tightened in the next step. Tightening them by hand is enough to prevent the dislocation of dowel pins.
- 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 on the top of sprocket teeth and its extended line in advance with paint.
c. After confirming the mating marks are aligned, tighten camshaft sprocket bolts.
- Secure camshaft using wrench at the hexagonal portion to tighten bolts.
d. Pull stopper pins out from timing chain tensioners (secondary).
4. Install tension guide.
5. Install timing chain (primary) as follows:
a. Install crankshaft sprocket.
- Make sure the mating marks on crankshaft sprocket face the front of engine.
b. Install the primary timing chain.
- Water pump (G).
- Install primary timing chain so the mating mark punched (B) on camshaft sprocket is aligned with the blue link (A) on the timing chain, while the mating mark notched (E) on the crankshaft sprocket (D) is aligned with the copper link (F) on the timing chain, as shown.
- When it is difficult to align mating marks (A) with (B) and (E) with (F) of the primary timing chain 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.
6. Install internal chain guide, slack guide and timing chain tensioner (primary).
CAUTION:
Do not overtighten slack guide bolts. It is normal for a gap to exist under the bolt seats when bolts are tightened to specification.
- When installing timing chain tensioner (primary), push in plunger and keep it pressed in with stopper pin.
- Remove any dirt and foreign materials completely from the back and the mounting surfaces of timing chain tensioner (primary).
- After installation, pull out stopper pin.
7. Make sure again that the mating marks on camshaft sprockets and timing chain have not slipped out of alignment.
8. Install RH and LH rocker covers. Removal And Installation.
9. Install front timing chain case. Front Timing Chain Case.
INSPECTION AFTER INSTALLATION
- Before starting the engine, check oil/fluid levels including engine coolant and engine oil. If the levels are lower than required quantity, fill to the specified level.
- Run engine to check for unusual noise and vibration.
NOTE:
If hydraulic pressure inside timing chain tensioner drops after removal and installation, slack in the guide may generate a pounding noise during and just after engine start. However, this is normal. Noise will stop after hydraulic pressure rises.
- Warm up engine thoroughly to make sure there is no leakage of fuel, exhaust gas, or any oil/fluids including engine oil and engine coolant.
- Bleed air from passages in lines and hoses, such as in cooling system.
- After cooling down the engine, again check oil/fluid levels including engine oil and engine coolant. Refill to specified level if necessary.
- Summary of the inspection items:
