GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2005 🢒 TopKick C-Series (Conventional) C4/C5 🢒 Engine 🢒 Engine Cooling 🢒 Upper Oil Pan Replacement

Removal Procedure
  1. Remove the oil level indicator.
  2. Remove the transmission. Refer to Transmission Replacement for the Allison Transmission or Transmission Replacement for the ZF S6-650 Transmission.
  3. Remove the lower oil pan. Refer to Lower Oil Pan Replacement .
  4. Remove the engine flywheel. Refer to Engine Flywheel Replacement .

    5. Object Number: 673564 Size: SH
  5. Remove the bolts and the battery positive and negative cable bracket from the front of the upper oil pan.

    6. Object Number: 673568 Size: SH
  6. Remove the nut and the battery positive and negative cable bracket from the right side of the upper oil pan.

    7. Object Number: 660335 Size: SH
  7. Remove the engine flywheel housing to upper oil pan bolts denoted by the black triangles.

    8. Object Number: 739051 Size: SH
  8. Remove the upper oil pan bolts and any brackets. Mark the bolt location of the bracket.
  9. Separate the upper oil pan from the engine block.
  10. Remove the upper oil pan. The oil level indicator tube needs to be removed while lowering the upper oil pan.

    11. Object Number: 663126 Size: SH
  11. Clean the upper oil pan.
  12. Clean the sealing surface on the engine block.
  13. Inspect the upper oil pan for cracks.
  14. Inspect the upper oil pan sealing surfaces and the engine block for damage.

Installation Procedure

    Object Number: 663817 Size: SH
  1. Apply a 2 mm (1/8 in) wide bead of sealant to the upper oil pan mating surfaces. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.
  2. Apply a 2 mm (1/8 in) wide bead of sealant to engine flywheel housing sealing surface. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.

    3. Object Number: 739051 Size: SH
  3. Install the upper oil pan to the engine block. Ensure the oil level indicator tube is installed into the upper oil pan.

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


    Object Number: 663823 Size: SH
  4. Install the upper oil pan bolts and any brackets.

    5. Tighten
    Tighten the upper oil pan bolts in the proper sequence to 21 N·m (15 lb ft).


    Object Number: 660335 Size: SH
  5. Install the engine flywheel housing to upper oil pan bolts denoted by the black triangles.

    6. Tighten
    Tighten the engine flywheel housing to upper oil pan bolts to 50 N·m (37 lb ft).


    Object Number: 673564 Size: SH
  6. Install the bolts and the battery positive and negative cable bracket to the front of the upper oil pan.

    7. Tighten
    Tighten the cable bracket bolts to 12 N·m (106 lb in).


    Object Number: 673568 Size: SH
  7. Install the nut and the battery positive and negative cable bracket from the right side of the upper oil pan.

    8. Tighten
    Tighten the cable bracket nut to 8 N·m (71 lb in).

  8. Install the engine flywheel. Refer to Engine Flywheel Replacement .
  9. Install the lower oil pan. Refer to Lower Oil Pan Replacement .
  10. Install the transmission. Refer to Transmission Replacement for the Allison Transmission or Transmission Replacement for the ZF S6-650 transmission.
  11. Lower the vehicle.
  12. Install the oil level indicator.
  13. Fill the engine with oil. Refer to Engine Oil and Oil Filter Replacement .