55. Timing Chain, Sprocket, and Tensioner Installation

TIMING CHAIN, SPROCKETS, AND TENSIONER
(UNIT REPAIR)

INSTALLATION





1. Install timing chain drive sprocket to crankshaft with timing mark in the 5 o'clock position.





2. Assemble intake camshaft sprocket to timing chain with timing mark lined up with the copper colored link.

IMPORTANT: Use care to make sure that the chain goes around both sides of the cylinder block bosses.





3. With chain hanging off the sprocket, lower timing chain through opening in cylinder head.





4. Route timing chain around-crankshaft sprocket and line up second silver link with timing mark on crankshaft sprocket in approximately the 5 o'clock position.

NOTICE: The camshaft bolt is a Torque-To-Yield (TTY) bolt, and must be discarded to prevent premature failure.

5. Install intake camshaft sprocket loosely onto intake camshaft and install new camshaft sprocket bolt finger tight. It is not necessary to align sprocket-to-camshaft offset notch at this time.





6. Install adjustable timing chain guide through opening in cylinder head and install adjustable timing chain bolt.
Torque: Timing Chain Guide (Adjustable Bolt: 10 Nm (89 inch lbs.)

NOTICE: The camshaft is a Torque-To-Yield (TTY) bolt, and must be discarded to prevent premature failure.





7. Install exhaust camshaft sprocket loosely onto exhaust camshaft using a new camshaft sprocket bolt.





8. Align timing mark on sprocket with silver link. Install bolt finger tight.

NOTICE: Do not turn camshaft more than 1/2 turn in either direction.. To do so may cause valve to piston contact. This may damage a valve and/or a piston. If camshaft is 180° out of time, use the following procedure to re-align cam.





9. Using a 24 mm wrench, first turn intake camshaft until alignment feature on back of camshaft sprocket seats in the notch in front of intake camshaft.
9.1. Turn crankshaft 45° in either direction.
9.2. Turn intake cam to appropriate location.
9.3. Turn crankshaft back to Top Dead Center (TDC).
10. When sprocket seats on cam, tighten sprocket bolt finger tight.





11. Verify that all colored links and appropriate timing marks are still aligned. If they are not, repeat portion of procedure necessary to align timing marks.
12. Install fixed timing chain guide.
Torque:
Timing Chain Guide (Fixed) Bolts: 10 Nm (89 inch lbs.)





13. Install upper timing chain guide.
Torque:
Timing Chain Guide (Upper) Bolts: 10 Nm (89 inch lbs.)





14. Using a 24 mm wrench, engage the hex on intake camshaft and tighten camshaft sprocket bolt using a torque wrench.
Torque:
Camshaft Sprocket Bolts: 85 Nm (63 ft. lbs.) + 30°

NOTICE: Do not turn camshaft more than 1/2 turn in either direction. To do so may cause valve to piston contact. This may damage a valve and/or a piston. If camshaft is 180° out of time, use the following procedure to re-align cam.

15. Using a 24 mm wrench, first turn intake camshaft until alignment feature on back of camshaft sprocket seats in the notch in front of intake camshaft.
15.1. Turn crankshaft 45° in either direction.
15.2. Turn intake cam to appropriate location.
15.3. Turn crankshaft back to Top Dead Center (TDC).
16. Using a 24 mm wrench, engage the hex on exhaust camshaft and tighten camshaft sprocket bolt using a torque wrench.
Torque:
Camshaft Sprocket Bolts: 85 Nm (63 ft. lbs.) + 30°





17. Measure the timing chain tensioner assembly from end to end.
A new tensioner should be supplied in the fully compressed non-active state. A tensioner in the compressed state will measure 72 mm (2.83 inch) (a) from end to end. A tensioner in the active state will measure 85 mm (3.35 inch) (a) from end to end. If the tensioner is not in the compressed state perform the following steps:





17.1. Hold a flat end of the tensioner piston with a wrench.
17.2. Rotate the piston clockwise by slightly less than one turn at which point resistance will be felt.





17.3. At this point the tensioner should measure 72 mm (2.83 inch) (a) from end to end. if the tensioner does not read 72 mm (2.83 inch) (a) from end to end, repeat steps 17.1 and 17.3.
18. Check to see if all thread sealant is removed from the timing chain tensioner threaded hole in the cylinder head.
19. Install timing chain tensioner assembly.
Torque:
Timing Chain Tensioner: 75 Nm (55 ft. lbs.)
20. The timing chain tensioner is released by compressing 2 mm (.079 inch) which will release the locking mechanism in the ratchet. The tensioner can be released by one of two methods:
20.1. If the engine has less than 30,000 miles (48,279 km) the tensioner can be released by starting the engine. This method cannot be used on an engine with over 30,000 miles or the cam chain may jump teeth on the cam sprockets.
20.2. If the engine has over 30,000 miles (48,279 km) on it use a suitable tool with a rubber tip on the end. Feed the tool down through the cam drive chant to rest on the cam chain. Then give a sharp jolt diagonally downwards to release the tensioner.
21. Install a new sealing washer on the timing chain tensioner assembly and install tensioner.





22. Install timing chain oiling nozzle.
Torque:
Timing Chain Oil Nozzle Bolt: 10 Nm (89 inch lbs.)





23. Apply thread sealant Loctite PST 565 (or equivalent) compound to thread. Install timing chain guide bolt access hole plug.
Torque:
Timing Chain Guide Bolt Access Hole Plug: 40 Nm (30 ft. lbs.)