GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Warning: Refer to Approved Equipment for Collision Repair Warning in the Preface section.


    Object Number: 1856462  Size: SH
  1. Disable the SIR system. Refer to SIR Disabling and Enabling.
  2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.
  3. Remove all related panels and components.
  4. Remove the rear impact bar. Refer to Rear Bumper Impact Bar Replacement.
  5. Remove the rear compartment. Refer to Rear Compartment Panel Replacement.
  6. Note the location and remove the sealers and anti-corrosion materials from the repair area. Refer to Anti-Corrosion Treatment and Repair.
  7. Repair as much of the damage as possible to the factory specifications.
  8. Warning: Refer to Collision Sectioning Warning in the Preface section.


    Object Number: 1856466  Size: SH

    Note: Save the cut-out piece of steel plate.

  9. Remove the shaded section (1) of the steel plate.

  10. Object Number: 1856472  Size: SH
  11. Determine the sectioning joint location (1) within the recommended area.

  12. Object Number: 1856481  Size: SH
  13. Determine the sectioning joint location.
  14. Mark the top of the frame rail at the sectioning location.
  15. At the mark, align a sliding square or similar tool square to the surface to the vertical walls of the frame rail.
  16. Scribe a line to both sides of the frame rail.

  17. Object Number: 1856498  Size: SH
  18. Apply masking tape (1) to the scribe line. Apply the tape completely around the frame rail.

  19. Object Number: 1856504  Size: SH
  20. Use a reciprocating saw or equivalent tool to cut the frame rail at the rear edge of the tape line.

  21. Object Number: 1856517  Size: SH
  22. Remove the damaged frame rail rear section (1).

Installation Procedure


    Object Number: 1856561  Size: SH
  1. Determine the sectioning joint location (1) from the new frame rail assembly.
  2. Cut the new frame rail rear section.

  3. Object Number: 748652  Size: SH
  4. Grind the existing frame rail sectioning location to a 45 degree angle.
  5. Clean and prepare all of the welded mating surfaces.
  6. Apply GM-approved weld-thru coating or equivalent to all mating surfaces. Refer to Anti-Corrosion Treatment and Repair.

  7. Object Number: 857910  Size: SH
  8. Make a 50 mm (2 in) weld backer sleeve. Refer to Sleeved Butt Joint Repair.
  9. Install the sleeve to the existing frame rail.

  10. Object Number: 1856545  Size: SH
  11. Position the service frame section (1) to the existing frame.

  12. Object Number: 1856550  Size: SH
  13. Maintain a gap of 1 1/2 times (1) the frame rail metal thickness at the sectioning joint. Clamp in place.
  14. Inspect the frame measurements 3-dimensional to ensure proper position in the service frame.

  15. Object Number: 1856556  Size: SH

    Note: Use a 25 mm (1 in) stitch weld for minimal heat distortion.

  16. Using a metal-inert gas (MIG) welder, weld the saved cut-out steel plate to the frame rail.
  17. Install the rear impact bar. Refer to Rear Bumper Impact Bar Replacement.
  18. Install the rear compartment. Refer to Rear Compartment Panel Replacement.
  19. Apply the sealers and anti-corrosion materials to the repair area. Refer to Anti-Corrosion Treatment and Repair.
  20. Note: Do NOT top coat any bonding surface. Use primer only on bonding surfaces. Refer to the adhesive manufacturer's recommendations.

  21. Paint the repair area. Refer to Basecoat/Clearcoat Paint Systems.
  22. Install all related panels and components.
  23. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.
  24. Enable the SIR system. Refer to SIR Disabling and Enabling.