GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2008 🢒 Sierra - 4WD 🢒 Engine 🢒 Engine Mechanical - 4.3L 🢒 Engine Front Cover Replacement

Removal Procedure

    Object Number: 349061 Size: SH
  1. Remove the water pump. Refer to Water Pump Replacement .
  2. Remove the crankshaft balancer. Refer to Crankshaft Balancer Replacement .
  3. Remove the oil pan. Refer to Oil Pan Replacement .
  4. Remove the engine shield bolts and shield.

    5. Object Number: 1877521 Size: SH
  5. Remove engine wire harness clip (1) from front cover.
  6. Disconnect the crankshaft position (CKP) sensor electrical connector (2).

    7. Object Number: 1877536 Size: SH
  7. Remove the CKP sensor bolt and sensor.

    8. Object Number: 1877540 Size: SH
  8. Remove and discard the CKP sensor O-ring seal.

    9. Object Number: 1877593 Size: SH
  9. Disconnect the engine wiring harness electrical connector from the camshaft position (CMP) sensor wiring harness jumper.

    10. Object Number: 1877007 Size: SH
  10. Remove the CMP sensor bolt.
  11. Remove the CMP sensor and wiring harness jumper from the engine front cover.
  12. Disconnect the CMP sensor wiring harness jumper from the CMP sensor.
  13. Remove the CMP sensor from the wiring harness jumper.

    14. Object Number: 1877601 Size: SH
  14. Remove the front cover bolts.

    15. Important: After the composite front cover is removed do not reinstall the front cover. Always install a NEW front cover.

  15. Remove and discard the front cover.
  16. Clean all sealing surfaces.

Installation Procedure

    Object Number: 1877601 Size: SH
  1. Install a NEW front cover.

    2. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  2. Install the front cover bolts.

    3. Tighten
    Tighten the bolts to 12 N·m (106 lb in).


    Object Number: 1877007 Size: SH

    Important: Do not reuse the original O-ring seal.

  3. If reinstalling the old CMP sensor, install a NEW O-ring seal onto the sensor.
  4. Install the CMP sensor to the wiring harness jumper.
  5. Connect the CMP sensor wiring harness jumper to the CMP sensor.
  6. Lubricate the O-ring seal with clean engine oil.
  7. Install the CMP sensor and wiring harness jumper to the engine front cover.
  8. Install the CMP sensor bolt.

    9. Tighten
    Tighten the bolt to 10 N·m (89 lb in).


    Object Number: 1877593 Size: SH
  9. Connect the engine wiring harness electrical connector from the CMP sensor wiring harness jumper.

    10. Object Number: 1877540 Size: SH

    Important: DO NOT reuse the original CKP sensor O-ring seal.

  10. Lubricate a NEW CKP sensor O-ring seal with clean engine oil.
  11. Install the NEW O-ring seal onto the CKP sensor.

    12. Object Number: 1877536 Size: SH

    Important: When installing the CKP sensor, make sure the sensor is fully seated before tightening the bolt. A poorly seated sensor may perform erratically and may set false DTCs.

  12. Install the CKP sensor and bolt.

    13. Tighten
    Tighten the bolt to 8 N·m (71 lb in).


    Object Number: 1877521 Size: SH
  13. Connect the CKP sensor electrical connector (2).
  14. Install the engine wire harness clip (1) to front cover.

    15. Object Number: 349061 Size: SH
  15. Install the engine shield and bolts.

    16. Tighten
    Tighten the bolts to 20 N·m (15 lb ft).

  16. Install the oil pan. Refer to Oil Pan Replacement .
  17. Install the crankshaft balancer. Refer to Crankshaft Balancer Replacement .
  18. Install the water pump. Refer to Water Pump Replacement .