GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

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

  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. Object Number: 866783  Size: SH
  4. Remove all related panels and components.
  5. Restore as much of the damage as possible to factory specifications. Refer to Dimensions - Body.
  6. Warning: Refer to Foam Sound Deadeners Warning in the Preface section.

  7. Note the location and remove the sealers and anti-corrosion materials from the repair area, as necessary. Refer to Anti-Corrosion Treatment and Repair.

  8. Object Number: 866784  Size: SH
  9. Perform the necessary procedures to gain access to the repair. Refer to Rear End Panel Replacement and Rear Compartment Panel Sectioning
  10. Note: Do not damage any inner panels or reinforcements.


    Object Number: 866788  Size: SH
  11. Mark the cut location, by measuring from the rear edge of the oval hole rearward (1) 270 mm (10 5/8 in).
  12. Cut the rear rail section.

  13. Object Number: 866808  Size: SH
  14. Remove the damaged rear rail section.

Installation Procedure


    Object Number: 866810  Size: SH
  1. Mark the cut location on the service rail by measuring 240 mm (9 7/16 in) from the rear edge of the oval hole rearward (1).
  2. Cut the rear rail service part.

  3. Object Number: 685168  Size: SH
  4. Cut and remove 30 mm (1 3/16 in) from the flanges on either side of the service section rail to create 30 mm (1 3/16 in) tabs (1).
  5. Cut 5 mm (1/4 in) wide gaps in the bottom corners (2).

  6. Object Number: 685170  Size: SH
  7. Step the tabs inward (1) to allow the service rail section to fit inside of the original rear rail.
  8. Note: The metal of the rear rail is of a heavy gage. However, the tabs can be created using the appropriate tools.

  9. Weld the tabs together along the lower edges (2).

  10. Object Number: 866813  Size: SH

    Note: If the location of the original plug weld holes can not be determined, or if structural weld-thru adhesive is present, space the plug weld holes every 40 mm (1 ½ in) apart.

  11. Drill 8 mm (5/16 in) plug weld holes along the sectioning cut on the original rail. Locate these holes 13 mm (1/2 in) from the edge and spaced 40 mm (1 1/2  in) apart.
  12. Prepare all mating surfaces as necessary.
  13. Apply GM-approved Weld-Thru coating or equivalent to all mating surfaces. Refer to Anti-Corrosion Treatment and Repair.

  14. Object Number: 866819  Size: SH
  15. Position the sectioned rear rail service part.

  16. Object Number: 685182  Size: SH
  17. Plug weld accordingly.

  18. Object Number: 685187  Size: SH
  19. Stitch the weld sectioning joint.
  20. To create a solid weld with minimum heat distortion, make 25 mm (1 in) stitch welds along the seam with 25 mm (1 in) gaps between them. Then go back and complete the stitch weld.
  21. Clean and prepare all welded surfaces.
  22. Complete the necessary procedures. Refer to Rear End Panel Replacement , Rear Compartment Panel Sectioning.
  23. Apply the sealers and anti-corrosion materials to the repair area, as necessary. Refer to Anti-Corrosion Treatment and Repair.
  24. Paint and repair the area. Refer to Basecoat/Clearcoat Paint Systems.
  25. Install all related panels and components.
  26. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.
  27. Enable the SIR system. Refer to SIR Disabling and Enabling.