GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

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

    Warning: Sectioning should be performed only in the recommended areas. Failure to do so may compromise the structural integrity of the vehicle and cause personal injury if the vehicle is in a collision.

  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: 1318649  Size: SH

    Note: The rear floor pan service part comes as a complete panel. You must make a cut to create the needed part for sectioning.

  4. Remove all related panels and components.
  5. Remove the sealers and anti-corrosion materials from the repair area, as necessary. Refer to Anti-Corrosion Treatment and Repair.
  6. Repair as much of the damaged area as possible. Refer to Dimensions - Body.

  7. Object Number: 1318653  Size: SH
  8. Remove the mounting plates (1) on top of the #5 bar floor panel.

  9. Object Number: 876976  Size: SH

    Note: Do not damage any adjacent panels or components when cutting or drilling out spot welds.

  10. Locate the rear edge of cross bar #5 from under the vehicle.
  11. Drill several 1/8 in holes in the floor pan only along the rear edge of the rear weld flange of cross bar #5. This will aid in identifying the location from the top side of the floor pan.

  12. Object Number: 1318660  Size: SH
  13. Cut the floor panel following the rear edge radius of the #5 bar. Where the #5 bar ends at the rails, cut the radius floor panel straight across.

  14. Object Number: 1206912  Size: SH
  15. Drill out all the spot welds along rails and the wheelhouses rearward of the cutline and remove the rear compartment floor panel. Note the number and location of welds for installation of the service assembly.

  16. Object Number: 1318662  Size: SH

    Note: Do not damage any inner panels or reinforcements.

  17. Cut slightly rearward of the #5 bar along the holes drilled in the floor pan. Later, the floor panel will be ground flush to the rear edge of the weld flange.

  18. Object Number: 1318664  Size: SH
  19. Cut and grind flush the original panel of the rear compartment panel at the rear edge of the #5 crossbar.

Installation Procedure


    Object Number: 877233  Size: SH
  1. On the rear compartment floor panel service part, measure from the front edge of the tire tub 200 mm (8 in). Scribe a line across the rear compartment pan.

  2. Object Number: 1206916  Size: SH
  3. Place a piece of masking tape along the top side of the rear compartment floor pan (a).

  4. Object Number: 1206925  Size: SH
  5. Cut along the forward edge of the tape, the edge that would be closest to the front of the #5 bar seat, and remove the rear portion of the panel.
  6. Drill 8 mm (5/16 in) plug weld holes in the service part as necessary in the corresponding locations noted on the original panel.
  7. Lay out and drill 2 additional rows of 8 mm (5/16 in) plug weld holes on top of the #5 bar weld flanges.
  8. Prepare all mating surfaces for welding as necessary.
  9. Apply GM-approved Weld-Thru Coating or equivalent to all mating surfaces. Refer to Anti-Corrosion Treatment and Repair.
  10. Position the rear floor pan to the vehicle using 3-dimensional measuring equipment. Clamp the part in place.

  11. Object Number: 1206931  Size: SH
  12. Plug weld accordingly.

  13. Object Number: 1206932  Size: SH
  14. Weld the seam along the front cut edge of the floor panel service part. To create a solid weld along the front of the service part with a minimum of heat distortion , make a stitch weld along the seam with 25 mm (1 in) gaps between each weld.