GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

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


    Object Number: 1856466  Size: SH

    Important: 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

    Important: 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. Important: 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 .