GM Service Manual Online
For 1990-2009 cars only

Pickup Box Outer Side Panel Replacement Weld-on

Removal Procedure

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

  1. Remove the box assembly..Refer to Pickup Box Replacement.
  2. Remove the endgate. Refer to Endgate Replacement.
  3. Remove the wheelhouse liner.
  4. Repair as much of the damage as possible, according to factory specifications.
  5. Note the location and remove the sealers and anti-corrosion materials from the repair area, as necessary. Refer to Anti-Corrosion Treatment and Repair.
  6. Note the number and location of all spot welds to be drilled out for installation of the service part.

  7. Object Number: 1238895  Size: SH
  8. Locate and drill out the spot welds on the front of the panel.

  9. Object Number: 1279756  Size: SH
  10. Locate and drill out the spot welds in the wheelhouse.

  11. Object Number: 1237642  Size: SH
  12. Locate and drill out the spot welds in the tail lamp pocket.

  13. Object Number: 1238925  Size: SH
  14. Locate and drill out the spot welds on the upper rail.

  15. Object Number: 1239080  Size: SH
  16. Remove the side panel.

Installation Procedure


    Object Number: 1239032  Size: SH
  1. Drill 8-mm (5/16-in) plug weld holes in the service part as noted.
  2. Prepare all mating surfaces as necessary.
  3. Apply GM-approved Weld-Thru coating or equivalent to all mating surfaces. Refer to Anti-Corrosion Treatment and Repair.

  4. Object Number: 1239060  Size: SH
  5. Position the service part onto the bed assembly.

  6. Object Number: 1279752  Size: SH
  7. Plug weld the upper rail.

  8. Object Number: 1238532  Size: SH
  9. Plug weld the tail lamp pocket.

  10. Object Number: 1281328  Size: SH
  11. Plug weld the wheelhouse.

  12. Object Number: 1279761  Size: SH
  13. Plug weld the front of the panel.
  14. Clean and prepare all welded surfaces.
  15. Apply the sealers and anti-corrosion materials to the repair area, as necessary. Refer to Anti-Corrosion Treatment and Repair.
  16. Paint and repair the area. Refer to Basecoat/Clearcoat Paint Systems.
  17. Install the wheelhouse liner.
  18. Install the endgate. Refer to Endgate Replacement.
  19. Install the box assembly. Refer to Pickup Box Replacement.

Pickup Box Outer Side Panel Replacement Bond-on

Removal Procedure

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

Note: This adhesive bonding procedure represents one manufacturer's installation application. Other manufacturers' procedures may vary, including MIG welding in some areas of the repair. Always follow the system manufacturer's instructions for application, handling, and curing.

Note: Before you begin the repair, refer to Metal Panel Bonding for proper adhesive preparations and general information.

  1. Remove the box assembly. Refer to Pickup Box Replacement.
  2. Remove the endgate. Refer to Endgate Replacement.
  3. Remove the wheelhouse liner.
  4. Repair as much or the damage as possible, according to factory specifications.
  5. Note the location and remove the sealers and anti-corrosion materials from the repair area, as necessary. Refer to Anti-Corrosion Treatment and Repair.
  6. Note the number and location of all spot welds to be drilled out for installation of the service part.

  7. Object Number: 1238895  Size: SH
  8. Locate and drill out the spot welds on the front of the panel.

  9. Object Number: 1279756  Size: SH
  10. Locate and drill out the spot welds in the wheelhouse.

  11. Object Number: 1237642  Size: SH
  12. Locate and drill out spot welds in the tail lamp pocket.

  13. Object Number: 1238925  Size: SH
  14. Locate and drill out spot welds on the upper rail.

  15. Object Number: 1239080  Size: SH
  16. Remove the side panel.

Installation Procedure


    Object Number: 1380019  Size: SH
  1. Grind the surface of the bed assembly mating flanges to bare steel. Do not damage the corners or thin the metal during the grinding process.

  2. Object Number: 1380025  Size: SH
  3. Grind the mating flanges of the service side panel to remove the E-coating. Do not damage the corners or thin the metal during the grinding operation.
  4. Clean the mating surfaces.

  5. Object Number: 1380031  Size: SH

    Note: The adhesive has a 40-50 minute working time. Do not allow the adhesive to cure prior to installing the service side panel.

  6. Apply a 3 to 6-mm (1/8 to 1/4-in) bead of metal panel bonding adhesive GM P/N 12378567 (Canadian P/N 88901675) or equivalent, to both of the mating surfaces.

  7. Object Number: 1380051  Size: SH
  8. Using a small acid brush, spread a coat of adhesive to both of the mating surfaces. Cover all of the bare metal to ensure corrosion protection.

  9. Object Number: 1380053  Size: SH
  10. Apply a 9 to 13-mm (3/8 to 1/2-in) bead of metal panel bonding adhesive GM P/N 12378567 (Canadian P/N 88901675) or equivalent, to the mating surface of the service side panel.

  11. Object Number: 1239060  Size: SH

    Note: Do NOT pull the panels apart after you have joined the panels together. Slide the panels against each other to realign the panels.

  12. Position the service side panel to the bed assembly.
  13. Clamp the service side panel into position.
  14. Using lacquer thinner remove the excess adhesive from the bed side panel area.
  15. Apply the sealers and anti-corrosion materials to the repair area, as necessary. Refer to Anti-Corrosion Treatment and Repair.
  16. Paint the repair area. Refer to Basecoat/Clearcoat Paint Systems.
  17. Install the wheelhouse liner.
  18. Install the endgate. Refer to Endgate Replacement.
  19. Install the box assembly. Refer to Pickup Box Replacement.