GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


Object Number: 1798551  Size: SH

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

Note: The damaged rear floor is cut along the rearward edge of the number 5 crossbar (1) and the service part is cut so that the new floor section extends to the forward edge of the 5 crossbar (2). This allows the two sections to overlap where the crossbar is attached (2). The service part is supplied as a rear floor assembly (3) which requires cutting to fit. The cut will be about 106 cm (41.7 in) from the rear edge of the floor panel.

  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. Repair as much of the damage as possible to factory specifications. Refer to Dimensions - Body.
  5. Warning: Refer to Foam Sound Deadeners Warning in the Preface section.

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

  7. Object Number: 1798554  Size: SH

    Note: Do not damage any inner panels or reinforcements.

  8. Cut the rear compartment panel above the rear weld flange of the lower crossmember.

  9. Object Number: 1798555  Size: SH
  10. Locate and drill out all factory welds along the top of the floor panel. Note the number and location of the welds for installation of the rear compartment panel.

  11. Object Number: 1798556  Size: SH
  12. Remove the damaged rear compartment panel.

Installation Procedure


    Object Number: 1798557  Size: SH
  1. Apply tape to the corresponding location on the replacement rear compartment panel.
  2. Cut on the forward edge of the tape line to create the replacement sectioning compartment panel.
  3. 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.


    Object Number: 1798558  Size: SH
  4. Drill 8 mm (5/16 in) plug weld holes as necessary in locations noted from the original rear floor pan.
  5. Drill 8 mm (5/16 in) plug weld holes spaced every 40 mm (1½ in) at the forward edge, of the rear compartment panel.
  6. Prepare all mating surfaces as necessary.
  7. Apply GM--approved Weld-Thru coating or equivalent to all mating surfaces. Refer to Anti-Corrosion Treatment and Repair.

  8. Object Number: 1798559  Size: SH
  9. Position the rear compartment panel to overlap the forward compartment panel.

  10. Object Number: 1798561  Size: SH
  11. Plug weld accordingly.
  12. Clean and prepare all welded surfaces.
  13. Apply the sealers and anti-corrosion materials to the repair area, as necessary. Refer to Anti-Corrosion Treatment and Repair.
  14. Paint and repair the area. Refer to Basecoat/Clearcoat Paint Systems.
  15. Install all related panels and components.
  16. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.
  17. Enable the SIR system. Refer to SIR Disabling and Enabling.