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Home >> Chevrolet >> 2021 >> Trailblazer RS, 4WD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 1 (Engine Mechanical - 1.2L (LIH)) >> Repair Instructions >> Timing Belt Replacement

Timing Belt Replacement

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Special Tools

Equivalent regional tools: Special Tools 

Removal Procedure

    NOTE:

    DO NOT remove the positive crankcase ventilation vacuum hose unless replacement of the hose is necessary.

    • The positive crankcase ventilation vacuum hose clamps are tamper-proof connections.
    • The turbocharger must be removed in order to install the positive crankcase ventilation vacuum hose at the turbocharger.
    • The camshaft cover, turbocharger, and vacuum hose can be removed together as an assembly and set aside so long as the tamper-proof connection remains intact.
    • The camshaft cover or turbocharger can be removed and set aside so long as the vacuum hose connection remains intact and undamaged.
    NOTE:

    If replacing timing belt due to maintenance interval the oil pump drive belt must also be replaced.

  1. Camshaft Cover - Position aside - Camshaft Cover Replacement 
  2. Camshaft Position Actuator Solenoid Valve - Intake - Remove - Camshaft Position Actuator Solenoid Valve Replacement - Intake
  3. Camshaft Position Actuator Solenoid Valve - Exhaust - Remove - Camshaft Position Actuator Solenoid Valve Replacement - Exhaust
  4. Starter - Remove - Starter Replacement (LIH)
  5. Timing Belt Lower Cover - Remove - Timing Belt Lower Cover Replacement 
  6. GM5274424Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    Ensure the EN-52476  Flywheel Locking Tool (1) is properly assembled, and the timing pin plunger (3) is retracted. When using the EN-52476  Flywheel Locking Tool as an timing device, adjust the pawl armature (4) so the pawl is not engaging the teeth once installed.

    EN-52476  Flywheel Locking Tool (1) - Install

  7. Bolt (2) - Install and tighten [2x]
  8. GM5371396Courtesy of GENERAL MOTORS COMPANY

    Crankshaft Balancer Bolt (1) - Install

  9. NOTE:

    The engine timing is located 118.14 degrees after top dead center.

  10. Adjust the engine to the engine timing position. Set the crankshaft in direction of engine rotation until the pin (2) of the EN-52476  Flywheel Locking Tool snaps automatically into the hole of the automatic transmission flex plate (3) or the engine flywheel.
  11. GM5372524Courtesy of GENERAL MOTORS COMPANY

    If the engine timing is adjusted correctly, the valves (1, 3) of the 3rd cylinder must be closed. Also the 2 flats (2) must stand in vertical position.

  12. GM5372525Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    The EN-52457  Camshaft Locking Tool has an identification for which side it must be used. Place the EN-52457  Camshaft Locking Tool with the identification mark I (1) facing upwards. Also the surface has an identification for the intake (2).

    EN-52457-2  Locking Tool - Intake (5) - Install

  13. Bolt (3, 4) - Install and tighten
  14. GM5372539Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    The EN-52457  Camshaft Locking Tool has an identification for which side it must be used. Place the EN-52457  Camshaft Locking Tool with the identification mark I (1) facing upwards. Also the surface has an identification for the exhaust (2).

    EN-52457-2  Locking Tool - Exhaust (5) - Install

  15. Bolt (3, 4) - Install and tighten [2x]
  16. GM5372540Courtesy of GENERAL MOTORS COMPANY

    Bolt @ EN-52458  VCP Locking Tool (2) - Loosen

  17. EN-52458  VCP Locking Tool (1) - Adjust
  18. EN-52458  VCP Locking Tool (1) - Install
  19. Bolt (3) - Install and tighten [4x] 6 N.m (53 lb in)
  20. Bolt (2) - Tighten
  21. GM5372542Courtesy of GENERAL MOTORS COMPANY

    Loosen the timing belt tensioner bolt (2) and release the tension from the timing belt tensioner (1). Rotate the timing belt tensioner counter-clockwise.

  22. EN-955-10-A  locking pin (3) - Install
  23. GM5372544Courtesy of GENERAL MOTORS COMPANY

    Install the EN-52458-3  locking tool (2) to the holes in the camshaft sprocket.

  24. Check that the EN-52458-3  locking tool (2) sits correctly in the hole of the camshaft sprocket.
  25. Bolt (3, 4) - Tighten [2x] 20 N.m (15 lb ft)
  26. Camshaft Sprocket Actuator Valve Bolt (1) - Loosen [2x]
  27. Bolt (3, 4) - Loosen [2x]
  28. GM5372540Courtesy of GENERAL MOTORS COMPANY

    Bolt (3) - Remove [4x]

  29. EN-52458  locking tool (1) - Remove
  30. GM5372546Courtesy of GENERAL MOTORS COMPANY

    Camshaft Sprocket Actuator Valve Bolt (1) - Remove and DISCARD [2x]

  31. GM5372547Courtesy of GENERAL MOTORS COMPANY

    Camshaft Sprocket (1) - Remove [2x]

  32. GM5372548Courtesy of GENERAL MOTORS COMPANY

    Timing Belt Tensioner Bolt (2) - Remove

  33. Timing Belt Tensioner (1) - Remove
  34. Timing Belt Idler Pulley Bolt (3) - Loosen
  35. Timing Belt Idler Pulley (4) - Remove
  36. GM5372549Courtesy of GENERAL MOTORS COMPANY

    Crankshaft Balancer Bolt (4) - Remove

  37. Crankshaft Sprocket (3) - Remove
  38. Crankshaft Front Oil Seal (2) - Remove and DISCARD
  39. Remove the timing belt (1) upwards.
  40. GM5372539Courtesy of GENERAL MOTORS COMPANY

    Bolt (3, 4) - Remove [2x]

  41. EN-52457-2  Locking Tool - Exhaust (5) - Remove
  42. GM5372525Courtesy of GENERAL MOTORS COMPANY

    Bolt (3, 4) - Remove

  43. EN-52457-2  Locking Tool - Intake (5) - Remove
  44. GM5274424Courtesy of GENERAL MOTORS COMPANY

    Bolt (2) - Remove [2x]

  45. EN-52476  Flywheel Locking Tool (1) - Remove

Installation Procedure

  1. GM5274424Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    Ensure the EN-52476  Flywheel Lock Tool (1) is properly assembled, and the timing pin plunger (3) is retracted. When using the EN-52476  Flywheel Lock Tool as an timing device, adjust the pawl armature (4) so the pawl is not engaging the teeth once installed.

    EN-52476  Flywheel Lock Tool (1) - Install

  2. Bolt (2) - Install and tighten [2x]
  3. GM5274430Courtesy of GENERAL MOTORS COMPANY

    Crankshaft Balancer Bolt (1) - Install

  4. NOTE:

    The engine timing is located 118.14 degrees after top dead center.

  5. Engage the EN-52476  Flywheel Lock Tool timing pin plunger (2).
  6. NOTE:

    Once there is resistance, do NOT turn the crankshaft further.

  7. Adjust the engine to the engine timing position. Use the crankshaft balancer bolt to slowly rotate the crankshaft in direction of engine rotation until the pin (3) of the EN-52476  Flywheel Lock Tool snaps automatically into the hole (4) of the automatic transmission flex plate or the engine flywheel.
  8. Adjust the pawl armature (5) on the EN-52476  Flywheel Lock Tool so the pawl is not engaging the teeth.
  9. GM5389389Courtesy of GENERAL MOTORS COMPANY

    Adjust the intake camshaft so that the valves (3) of the 3rd cylinder are closed and the 2 flats (2) stand in vertical position. Use the EN-52455  Open End Wrench (1).

  10. GM5372525Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    The EN-52457  Camshaft Locking Tool has an identification for which side of the tool must be facing upward. Place the EN-52457  Camshaft Locking Tool with the I (1) facing upwards. The surface of the tool will also have the identification intake (2) for use on the intake camshaft.

    EN-52457-2  locking tool (5) @ Intake Camshaft - Install

  11. Bolt (3, 4) - Install and tighten
  12. GM5389391Courtesy of GENERAL MOTORS COMPANY

    Adjust the exhaust camshaft so that the valves (3) of the 3rd cylinder are closed and the 2 flats (2) stand in vertical position. Use the EN-52455  Open End Wrench (1)

  13. GM5372539Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    The EN-52457  Camshaft Locking Tool has an identification for which side of the tool must be facing upward. Place the EN-52457  Camshaft Locking Tool with the I (1) facing upwards. The surface of the tool will also have the identification exhaust (2) for use on the exhaust camshaft.

    EN-52457-1  locking tool (5) @ Exhaust Camshaft - Install

  14. Bolt (3, 4) - Install and tighten [2x]
  15. GM5389393Courtesy of GENERAL MOTORS COMPANY

    Install the timing belt (1) downwards.

  16. Crankshaft Front Oil Seal (2) - Install NEW
  17. Crankshaft Sprocket (3) - Install
  18. Crankshaft Balancer Bolt (4) - Install
  19. GM5372547Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    The front of the camshaft sprockets is recognizable by the pin (2).

    Camshaft Sprocket (1) - Install [2x]

  20. GM5372546Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    The sprocket bolts must be tightened enough to remove axial play between the sprocket and cam. The bolts must be loose enough to allow the sprocket to turn independently of camshafts.

    Camshaft Sprocket Actuator Valve Bolt (1) - Install NEW and hand tighten [2x]

  21. GM5372548Courtesy of GENERAL MOTORS COMPANY

    Timing Belt Tensioner (1) - Install

  22. Timing Belt Tensioner Bolt (2) - Loosely install
  23. Timing Belt Idler Pulley (4) - Install
  24. Timing Belt Idler Pulley Bolt (3) - Install and tighten 36 N.m (27 lb ft)
  25. GM5389395Courtesy of GENERAL MOTORS COMPANY

    EN-955-10-A  pin (2) - Remove

  26. NOTE:

    10 degrees past nominal position can be verified when the hole in the mobile index pointer is no longer visible behind the gap of the front plate.

  27. Rotate the timing belt tensioner clockwise to tension the timing belt tensioner (1) to the nominal position (4), and an additional 10 degrees (5).
  28. Timing Belt Tensioner Bolt (3) - Tighten 36 N.m (27 lb ft)
  29. GM5372540Courtesy of GENERAL MOTORS COMPANY

    Bolt (2) - Loosen

  30. Slide the EN-52458  VCP Locking Tool (1) apart.
  31. EN-52458  VCP Locking Tool (1) - Install
  32. Bolt (3) - Install and tighten [4x] 6 N.m (53 lb in)
  33. Bolt (2) - Tighten
  34. GM5389396Courtesy of GENERAL MOTORS COMPANY

    Install the EN-52458-3  locking tool (2) to the holes in the intake camshaft sprocket.

  35. Check that the EN-52458-3  locking tool (2) sits correctly in the hole of the camshaft sprocket.
  36. NOTE:

    A second technician is required.

  37. Tighten the EN-52458-3  locking tool (2) to 20 N.m (15 lb ft). Rotate the EN-52458-3  locking tool counter-clockwise.
  38. While holding the EN-52458-3  locking tool to 20 N.m (15 lb ft), tighten the bolt (3) to 20 N.m (15 lb ft).
  39. Camshaft Sprocket Actuator Valve Bolt (1) @ Intake Camshaft - Tighten
    1. First Pass: 50 N.m (37 lb ft)
    2. Final Pass: 28 degrees, use the EN-45059  meter
  40. GM5389399Courtesy of GENERAL MOTORS COMPANY

    Install the EN-52458-3  locking tool (3) to the holes in the exhaust camshaft sprocket.

  41. Check that the EN-52458-3  locking tool (3) sits correctly in the hole of the camshaft sprocket.
  42. NOTE:

    A second technician is required.

  43. Tighten the EN-52458-3  locking tool (3) to 20 N.m (15 lb ft). Rotate the EN-52458-3  locking tool counter-clockwise.
  44. While holding the EN-52458-3  locking tool to 20 N.m (15 lb ft), tighten the bolt (2) to 20 N.m (15 lb ft).
  45. Camshaft Sprocket Actuator Valve Bolt (1) @ Exhaust Camshaft - Tighten
    1. First Pass: 50 N.m (37 lb ft)
    2. Final Pass: 28 degrees, use the EN-45059  meter
  46. GM5372540Courtesy of GENERAL MOTORS COMPANY

    Bolt (3) - Remove [4x]

  47. EN-52458  locking tool (1) - Remove
  48. GM5372539Courtesy of GENERAL MOTORS COMPANY

    Bolt (3, 4) - Remove [2x]

  49. EN-52457-1  locking tool (5) - Remove
  50. GM5372525Courtesy of GENERAL MOTORS COMPANY

    Bolt (3, 4) - Remove

  51. EN-52457-2  locking tool (5) - Remove
  52. GM5274430Courtesy of GENERAL MOTORS COMPANY

    Turn the crankshaft 720 degrees in the direction of engine rotation by the crankshaft balancer bolt (1) until the pin (2) of the EN-52476  lock tool snaps automatically into the hole (3) of the automatic transmission flex plate or the engine flywheel.

  53. GM5389401Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    The nominal position of the timing belt tensioner is when the mobile index (2) sits in the middle between the gap of the front plate (3). A tolerance is given when half of the hole (4) is visible (+/- 5 degrees).

    Check that the timing belt tensioner (1) is in the nominal position.

  54. If not, repeat the step to adjust the tensioner.
  55. GM5372525Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    The EN-52457  Camshaft Locking Tool has an identification for which side of the tool must be facing upward. Place the EN-52457  Camshaft Locking Tool with the I (1) facing upwards. The surface of the tool will also have the identification intake (2) for use on the intake camshaft.

    EN-52457-2  locking tool (5) @ Intake Camshaft - Install

  56. GM5372539Courtesy of GENERAL MOTORS COMPANY
    NOTE:

    The EN-52457  Camshaft Locking Tool has an identification for which side of the tool must be facing upward. Place the EN-52457  Camshaft Locking Tool with the I (1) facing upwards. The surface of the tool will also have the identification exhaust (2) for use on the exhaust camshaft.

    EN-52457-2  locking tool (5) - Install

  57. If the EN-52457  Camshaft Locking Tool can be installed, the engine timing is properly adjusted.
  58. If the EN-52457  Camshaft Locking Tool can not be installed, repeat the steps to set the engine timing.
  59. EN-52457  Camshaft Locking Tool - Remove
  60. GM5274430Courtesy of GENERAL MOTORS COMPANY

    Crankshaft Balancer Bolt (1) - Remove

  61. GM5274424Courtesy of GENERAL MOTORS COMPANY

    Bolt (2) - Remove [2x]

  62. EN-52476  Flywheel Locking Tool (1) - Remove
  63. Timing Chain Lower Cover - Install - Timing Belt Lower Cover Replacement 
  64. Starter - Install - Starter Replacement (LIH)
  65. Camshaft Position Actuator Solenoid Valve - Exhaust - Install - Camshaft Position Actuator Solenoid Valve Replacement - Exhaust
  66. Camshaft Position Actuator Solenoid Valve - Intake - Install - Camshaft Position Actuator Solenoid Valve Replacement - Intake
  67. Camshaft Cover - Install - Camshaft Cover Replacement 
  68. If NEW timing belt and oil pump belt were installed, perform timing belt life reset. Timing Belt Life Reset