GM Service Manual Online
For 1990-2009 cars only

    Object Number: 1559895  Size: SH

    Important: 

       • The alignment of the structural oil pan is critical. The rear bolt hole locations of the oil pan provide mounting points for the transmission housing. To ensure the rigidity of the powertrain and correct transmission alignment, it is important that the rear of the block and the rear of the oil pan are flush, or even. The rear of the oil pan must NEVER protrude beyond the engine block and transmission housing plane.
       • Do not use the oil pan gasket again.
       • It is not necessary to rivet the NEW gasket to the oil pan.

  1. Apply a 5 mm (0.2 in) bead of sealant GM P/N 12378521 (Canadian P/N 88901148), or equivalent, 20 mm (0.8 in) long to the engine block. Apply the sealant directly onto the tabs of the front cover gasket that protrude into the oil pan surface. Refer to Adhesives, Fluids, Lubricants, and Sealers .

  2. Object Number: 63175  Size: SH
  3. Apply a 5 mm (0.2 in) bead of sealant GM P/N 12378521 (Canadian P/N 88901148), or equivalent, 20 mm (0.8 in) long to the engine block. Apply the sealant directly onto the tabs of the rear cover gasket that protrude into the oil pan surface.

  4. Object Number: 1408873  Size: SH

    Important: Ensure the oil gallery passages in the oil pan and engine block properly align with the oil pan gasket.

  5. Pre-assemble the oil pan gasket to the pan.
  6. 3.1. Install the gasket onto the oil pan.
    3.2. Install the oil pan bolts (439, 453) to the pan and through the gasket.
  7. Install the oil pan (400), gasket and bolts to the engine block.
  8. Tighten bolts finger tight. Do not overtighten.

  9. Object Number: 1681942  Size: SH
  10. Place a straight edge across the rear of the engine block and the rear of the oil pan at the transmission housing mounting surfaces.
  11. Notice: Refer to Fastener Notice in the Preface section.

  12. Align the oil pan until the rear of engine block and rear of oil pan are flush or even.
  13. Tighten

    1. Tighten the oil pan-to-block and oil pan-to-front cover bolts to 25 N·m (18 lb ft).
    2. Tighten the oil pan-to-rear cover bolts to 12 N·m (106 lb in).
  14. Measure the oil pan-to-engine block alignment (a).
  15. 8.1. Place a straight edge across the rear of the engine block and rear of oil pan at the transmission housing mounting surfaces.

            Important: The rear of the oil pan must NEVER protrude beyond the engine block and transmission housing mounting surfaces.

    8.2. Insert a feeler gage between the straight edge and the oil pan transmission housing mounting surface, and inspect to ensure there is no greater than a 0.1 mm (0.004 in) gap (a) between the pan and straight edge.
    8.3. If the oil pan alignment is not within specifications, remove the oil pan and repeat the above procedure.