GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2008 🢒 Sierra - 2WD 🢒 Engine 🢒 Engine Mechanical - 6.6L 🢒 Oil Pump Replacement

Removal Procedure

    Object Number: 738908 Size: SH
  1. Remove the engine front cover. Refer to Engine Front Cover Replacement.
  2. Remove the upper oil pan. Refer to Upper Oil Pan Replacement.
  3. Remove the oil pump screen bolts and nuts.
  4. Remove the oil pump screen.
  5. Remove and discard the oil pump screen gasket.

    6. Object Number: 660539 Size: SH
  6. Block the crankshaft from turning with a wooden handle.

    7. Object Number: 776631 Size: SH

    Important: Look for an "L" on the end of the oil pump shaft. If there is an "L" present, the nut and shaft have left hand threads. Service the nut accordingly.

  7. While holding the secondary oil pump shaft with a hex driver, remove the oil pump driven gear nut.

    8. Object Number: 738905 Size: SH
  8. Remove the oil pump driven gear.

    9. Object Number: 738904 Size: SH

    Important: Do not damage the crankshaft reluctor. Do not remove the crankshaft reluctor to oil pump drive bolts.

  9. Remove the oil pump drive gear and crankshaft reluctor.
    10. • Use a brass drift.
    • Tap on the back as close to the center of the reluctor.

    Object Number: 738906 Size: SH
  10. Remove the hex head and the allen head bolt in order to remove the oil pump.
  11. Remove the oil pump.
  12. Remove the O-ring seal for the oil pump.
  13. If required, clean and inspect the oil pump. Refer to Oil Pump Cleaning and Inspection.

Installation Procedure

    Object Number: 738906 Size: SH
  1. Install a NEW oil pump O-ring seal.

    2. Notice: Refer to Fastener Notice in the Preface section.

  2. Install the oil pump.
  3. Install the oil pump bolts.

    4. Tighten
    Tighten the bolts to 21 N·m (15 lb ft).

  4. Inspect the oil pump drive gear for wear.
  5. Replace the oil pump drive gear pin if worn.

    6. Object Number: 738904 Size: SH
  6. Install the oil pump drive gear and reluctor to the crankshaft.

    7. Object Number: 738905 Size: SH
  7. Install the oil pump driven gear.

    8. Object Number: 776631 Size: SH
  8. While holding the secondary oil pump shaft with a hex driver, install the oil pump driven gear nut.

    9. Tighten
    Tighten the nut to 100 N·m (74 lb ft).


    Object Number: 738908 Size: SH
  9. Install a NEW oil pump screen gasket to the oil pump.
  10. Install the oil pump screen.
  11. Install the oil pump screen bolts and nuts.

    12. Tighten
    Tighten the bolts/nuts to 25 N·m (18 lb ft).

  12. Install the engine front cover. Refer to Engine Front Cover Replacement.
  13. Install the upper oil pan. Refer to Upper Oil Pan Replacement.