GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


Object Number: 404463  Size: SH

Important: The rear floor is sold as a complete assembly including the rear rails, cross members and rear extension; or sold separately as a floor pan (skin) with exhaust heat shield only.

  1. Remove all related panels and components, including fuel tank.
  2. Visually inspect and restore as much of the damage as possible.
  3. Remove sealers, sound deadeners and anti-corrosion materials as necessary.

  4. Object Number: 404466  Size: SH
  5. Locate factory seam at front edge of crossbar, rearward of seat back.
  6. Locate, mark and drill through one layer ONLY, all factory welds which secure the floor to the rails. Note the number and location of welds for installation of the floor service panel.
  7. Drill completely through the welds that attach the floorpan to the inner wheelhouse.
  8. Remove both inner wheelhouse braces. Identify the weld locations and drill through one layer of metal ONLY.
  9. Remove the damaged floor section.

Installation Procedure

  1. Prepare mating surfaces with suitable weld-through primer.
  2. Drill 8 mm (5/16 in) plug weld holes as necessary in the locations noted from the original floor.
  3. Important: In any area damaged beyond recognition, space plug weld holes every 40 mm (1 1/2 in) apart. Sound deadeners along the inner wheelhouse must be removed prior to welding new panels in place.

  4. Position the service floor pan, check for proper fit using three-dimensional measuring.
  5. Plug weld accordingly.

  6. Object Number: 404474  Size: SH
  7. Install both wheelhouse braces.
  8. Clean and prepare all welded surfaces.
  9. Important:  Prior to refinishing, refer to GM 4901M--2000 "GM Approved Refinish Materials" for recommended products. Do not combine paint systems. Refer to paint manurfacturer's recommendations.

  10. Apply an approved anti-corrosion primer.
  11. Apply body sealers and finish as necessary.
  12. Install all related panels and components.