GM Service Manual Online
For 1990-2009 cars only

Special Tools

EN 48589 Crankshaft Rotation Socket

For equivalent regional tools, refer to Special Tools.


    Object Number: 1852303  Size: SH
  1. Ensure the crankshaft sprocket is installed with the timing mark (1) visible.

  2. Object Number: 2026685  Size: SH
  3. Install the crankshaft sprocket (1) onto the nose of the crankshaft.
  4. Align the notch in the crankshaft sprocket with the pin in the crankshaft.
  5. Slide the crankshaft sprocket on the crankshaft nose until the crankshaft sprocket contacts the step in the crankshaft.

  6. Object Number: 1866950  Size: SH
  7. Ensure the crankshaft is in the stage one timing position with the crankshaft sprocket timing mark (1) aligned to the stage one timing mark on the oil pump cover (2) using the EN 48589 socket . Refer to Camshaft Timing Drive Chain Alignment Diagram.