Timing Chain Replacement: Installation

1. Install timing chain drive sprocket to crankshaft.
   Fig 1: Installing Timing Chain Drive Sprocket To Crankshaft

   Courtesy of GENERAL MOTORS CORP.
   NOTE: Set crankshaft to 60° before top-dead-center (TDC) to prevent valves to piston contact.
2. Using dampener, rotate crank so that mark on timing chain drive sprocket is at 5 o'clock position.
3. Set crankshaft to 60° before top dead center.
   Fig 2: Setting Crankshaft To 60° Before Top Dead Center

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4. Position exhaust camshaft with offset slot to 2 o' clock position.
   Fig 3: Positioning Exhaust Camshaft

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5. Position intake camshaft with offset slot to 11 o'clock position.
   Fig 4: Positioning Intake Camshaft

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6. Assemble chain to intake camshaft sprocket aligning copper link to INT diamond timing mark on camshaft sprocket.
   Fig 5: Assembling Chain-To-Intake Camshaft Sprocket

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   NOTE: When lowering timing chain into cylinder head, rotate assembly 90° to allow chain to fall between cylinder block bosses, then rotate assembly back so that camshaft sprocket is facing forward.
7. Lower assembly through chain housing opening on top of cylinder head. Use care to make sure that chain goes around both sides of cylinder block bosses.
   Fig 6: Lowering Assembly Through Chain Housing

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   NOTE: The crankshaft sprocket timing mark will be at approximately 5 o'clock position.
8. Route chain around crankshaft sprocket and align silver link to timing mark.
   Fig 7: Routing Chain Around Crankshaft Sprocket

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   NOTE: The camshaft sprocket bolts are torque-to-yield bolts and are not reusable. They must be replaced when removed.
9. Install intake camshaft sprocket with chain in proper position to camshaft. Rotate intake camshaft using a 24 mm wrench on flats on camshaft until camshaft aligns with sprocket.
10. Install new intake camshaft sprocket bolt and finger tighten.
    NOTE: With timing chain aligned to crankshaft sprocket mark, the crankshaft can be rotated slightly to eliminate slack from the fixed side of timing chain. Be sure that marks are properly aligned.
    Fig 8: Installing Intake Camshaft Sprocket With Chain In Proper Position To Camshaft

    Courtesy of GENERAL MOTORS CORP.
    NOTE: Make sure crankshaft marks and camshaft marks aligns with colored links.
11. Install adjustable timing chain guide through opening at top of cylinder head and install chain guide bolt.

    Torque: 

    Timing Chain Guide (Adjustable) Bolt: 10 N.m (89 in-lbs) 

    Fig 9: Installing Adjustable Timing Chain Guide

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12. Install exhaust camshaft sprocket loosely on exhaust camshaft with timing mark on sprocket aligned with silver link.
13. Install new camshaft sprocket bolt loosely.
    Fig 10: Installing New Camshaft Sprocket Bolt

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14. Align exhaust camshaft sprocket with chain in proper position to camshaft. Rotate exhaust clockwise using a 24 mm wrench on flats on camshaft until camshaft aligns with sprocket.
    Fig 11: Aligning Exhaust Camshaft Sprocket

    Courtesy of GENERAL MOTORS CORP.
15. Verify that all colored links are aligned with appropriate intake (1), crankshaft sprocket (2), and exhaust marks.
16. Verify crankshaft sprocket timing mark is at 5 o'clock.
17. If marks are not correct you must repeat timing procedure.
    Fig 12: Verifying Crankshaft Sprocket Timing Mark

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18. Install fixed timing chain guide and bolts.

    Torque: 

    Timing Chain (Fixed) Bolts: 10 N.m (89 in-lbs) 

    Fig 13: Installing Fixed Timing Chain Guide And Bolts

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19. Apply thread sealant Permatex® Thread Pipe Sealant (or equivalent) compound to thread. Install fixed guide bolt access hole plug.

    Torque: 

    Timing Chain Guide Bolt Access Hole Plug: 40 N.m (30 ft-lbs) 

    Fig 14: Installing Timing Chain Guide Bolt Access Hole Plug

    Courtesy of GENERAL MOTORS CORP.
20. Install upper timing chain guide and bolts.

    Torque: 

    Timing Chain Guide (Upper) Bolts: 10 N.m (89 in-lbs) 

    Fig 15: Installing Upper Timing Chain Guide And Bolts

    Courtesy of GENERAL MOTORS CORP.
    NOTE: Use a 24 mm wrench to support the camshaft while applying torque to camshaft sprocket bolt. Do not torque camshaft bolts against timing chain, as it may damage timing chain.
21. Tighten intake and exhaust camshaft sprocket bolts while holding camshaft with 24 mm wrench.

Torque: 

Camshaft Sprocket Bolts: 85 N.m (63 ft-lbs)+ 30° 

Fig 16: Tightening Intake And Exhaust Camshaft Sprocket Bolts

Courtesy of GENERAL MOTORS CORP.

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

   Courtesy of GENERAL MOTORS CORP.
   1. 22.1 Hole the flat end of tensioner piston with Timing Chain Tensioner Unloader J45027.
   2. 22.2 Using timing chain tensioner unloader J45027, rotate piston clockwise slightly at which resistance will be felt and will collapse and lock in.
   3. 22.3 At this point tensioner should measure approximately 72 mm (2.83 in.) from end-to-end. If tensioner does not read 72 mm, repeat this procedure.
2. Remove all thread material from timing chain tensioner hole.
   Fig 18: Removing All Thread Material From Timing Chain Tensioner Hole

   Courtesy of GENERAL MOTORS CORP.
3. Install timing chain tensioner.

   Torque: 

   Timing Chain Tensioner: 75 N.m (55 ft-lbs) 

4. Timing chain tensioner is released by compressing it 2 mm (.079 in.) which will release locking mechanism in ratchet. Tensioner can be released by one of two methods:
   • If engine has less than 48,279 km (30,000 miles) tensioner can be released by starting engine.

     This method cannot be used on engine with over 30,000 miles or cam chain may jump teeth on cam sprockets.

   • If engine has over 48,279 km (30,000 miles) on it use a suitable tool with a rubber tip on the end. Feed tool down through cam drive to rest on cam chain, giving a sharp jolt diagonally downward to release tensioner.
     Fig 19: Installing Timing Chain Tensioner

     Courtesy of GENERAL MOTORS CORP.
5. Raise vehicle if necessary.
6. Install new front cover gasket.
7. Install front cover assembly.
8. Install front cover assembly bolts.

   Torque: 

   Front Cover-to-Block Bolts: 25 N.m (18 ft-lbs) 

9. Install front cover water pump bolt.

   Torque: 

   Water Pump Bolts: 25 N.m (18 ft-lbs) 

   Fig 20: Installing Front Cover Assembly Bolts

   Courtesy of GENERAL MOTORS CORP.
10. Lubricate front seal and sealing surface of pulley with clean motor oil.
11. Install balancer pulley onto crankshaft indexing keyway. Use care to properly align flats on balancer pulley with flats on oil pump drive in front cover assembly.
12. Install crankshaft damper pulley.
    Fig 21: Installing Crankshaft Damper Pulley

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13. Install new crankshaft balancer pulley bolt with washer assembly.
    Fig 22: Installing New Crankshaft Balancer Pulley Bolt

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14. Install crankshaft pulley holder J38122.

    Torque: 

    Crankshaft Pulley Bolt: 100 N.m (74 ft-lbs) + 75° 

    Fig 23: Installing Crankshaft Pulley Holder

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15. Install accessory drive belt tensioner.

    Torque: 

    Drive Belt Tensioner Bolt: 45 N.m (33 ft-lbs) 

16. Route belt around alternator and A/C compressor.
17. Install accessory drive belt tool J39914 onto tensioner and unload spring tension from tensioner while positioning belt.
18. Release tensioner and remove tool.
    Fig 24: Unloading Spring Tension From Tensioner While Positioning Belt

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19. Install right-hand engine bracket and bolts.

    Torque: 

    Engine Mount Bracket-to-Engine Bolts: 110 N.m (81 ft-lbs) 

    Fig 25: Installing Right-Hand Engine Bracket And Bolts

    Courtesy of GENERAL MOTORS CORP.
20. Install right-hand engine mount onto body side rail studs.
21. Install right hand engine moun-to-body nuts.

    Torque: 

    Engine Mount-to-Body Nuts: 110 N.m (81 ft-lbs) 

22. Install right-hand engine mount-to-engine mount bracket bolts.

    Torque: 

    Engine Mount-to-Engine Mount Bracket Bolts: 50 N.m (37 ft-lbs) 

23. Remove 3-Bar Engine Support Fixture.
24. Install right engine inner splash shield.
25. Install right wheel and hand-tighten wheel nuts.
26. Tighten wheel nuts.

    Torque: 

    Wheel Nuts: 125 N.m (92 ft-lbs) 

    Fig 26: Installing Right-Hand Engine Mount-To-Engine Mount Bracket Bolts

    Courtesy of GENERAL MOTORS CORP.
27. Visually inspect camshaft cover gasket for signs of leakage. Camshaft cover gasket is reusable if not damaged.
28. Assemble camshaft cover and gasket using care to make sure that gasket is located in retaining groove on camshaft cover.
29. Install cover on cylinder head and hand-tighten bolts.

    Torque: 

    Camshaft Cover Bolts: 10 N.m (89 in-lbs) 

    Fig 27: Installing Cover On Cylinder Head

    Courtesy of GENERAL MOTORS CORP.
30. Re-position fuel line assembly.
    NOTE: An open-end wrench must be used to support the fuel line to rail connection during loosening/tightening to avoid damaging fuel rail assembly.
31. Install transfer line fitting at fuel to fuel rail.

    Torque: 

    Transfer Line Fitting-to-Fuel Rail: 10 N.m (89 in-lbs) 

    Fig 28: Installing Transfer Line Fitting At Fuel To Fuel Rail

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32. Connect fuel rail bracket and bolt to cylinder head.

    Torque: 

    Fuel Line Bracket Bolt: 10 N.m (89 in-lbs) 

    Fig 29: Connecting Fuel Rail Bracket

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33. Connect ground strap to camshaft cover assembly.

    Torque: 

    Camshaft Cover Ground Strap Bolts: 10 N.m (89 in-lbs) 

34. Connect degas hose and attach to fuel rail.
35. Connect coolant pipe bracket bolts to cylinder head.

    Torque: 

    Coolant Pipe Bracket Bolt: 10 N.m (89 in-lbs) 

    Fig 30: Connecting Ground Strap To Camshaft Cover Assembly

    Courtesy of GENERAL MOTORS CORP.
36. Install spark plugs (if removed).

    Torque: 

    Spark Plugs: 20 N.m (15 ft-lbs) 

37. Install ignition module assembly to cam cover and hand-tighten retaining bolts.

    Torque: 

    Ignition Module-to-Camshaft Cover Bolts: 8 N.m (71 in-lbs) 

    Fig 31: Installing Ignition Module Assembly To Cam Cover

    Courtesy of GENERAL MOTORS CORP.
38. Install air cleaner assembly and bolt.

    Torque: 

    Air Cleaner-to-Support Bracket Bolt: 10 N.m (89 in-lbs) 

39. Install outlet resonator/duct assembly into position.
40. Connect PCV fresh air vent hose assembly.
41. Tighten clamp at throttle body assembly.
42. Position outlet resonator/duct assembly up with support bracket and install push-pin.
    Fig 32: Installing Outlet Resonator/Duct Assembly

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43. Tighten clamp at air cleaner assembly.
44. Connect intake air temperature (IAT) sensor connector.
45. Connect negative battery cable.

    Torque: 

    Battery Terminal Bolt: 17 N.m (13 ft-lbs) 

46. Start vehicle and inspect for leaks.