The damaged floor is cut along the rearward edge of the no. 5 crossbar, and the service part is cut so that the new floor section extends to the front edge of the no. 5 crossbar. This allows the two sections to overlap where the crossbar is attached. The spare wheel well panel comes with the service floor panel, and is also available separately. Rear floor reinforcements are only available separately.

1. Remove all the related panels and components, including the rear end panel, quarter panel extensions or quarter panels as necessary, and the three reinforcements on top of the floor panel.
2. Visually inspect the damaged area.
3. Restore as much of the damage as possible to factory specifications.
4. Remove sealers, sound deadeners and anti-corrosion materials as necessary.
5. Locate all factory welds rearward of the no. 5 crossbar including those along the lower edge of the wheelhouse.

Important: Note the number and location of welds for installation of the floor service assembly.

6. Mark the factory welds.

Important: Drill out only the factory welds rearward of the no. 5 crossbar. Do not drill out the welds attaching the no. 5 crossbar to the floor.

7. Drill out all factory welds.
8. Cut the damaged floor along the rear edge of the no. 5 crossbar, taking care not to damage the rear rails, no. 5 crossbar or wheelhouse.
9. Remove the damaged floor section.

1. Measure 850 mm (33.5 in) from the rear edge of the panel forward.
2. Cut the service part.
3. Prepare the mating surfaces.
4. Check for proper fit of the floor service assembly, allowing it to overlap the original floor on top of the rear crossbar.
5. Mark the location of the rear rail and crossbar flanges on the bottom of the floor service panel, before removing the floor panel.
6. Position right and left floor reinforcements and attach them temporarily.
7. Remove the floor panel to locate the markings made on the bottom side of the panel.
8. Drill 8 mm (0.31 in) holes for plug welding as necessary in the noted locations.

Important: The drill holes should be drilled through the reinforcements and the floor panel in order to allow both panels to be plug welded to the rail flanges.

When sectioning the right rear rail and floor panel, it may be necessary to grind the top surface of the rear rail flanges for proper fit of the service floor panel.
9. Drill holes where the new floor section attaches to the rear rail and crossbar flanges.
10. Detach the floor reinforcements.
11. Position the service panel.
12. Check for proper fit with frequent measurements.



13. Plug weld in the area the reinforcement overlaps the crossbar.
14. Position the reinforcements.
15. Check for proper fit and alignment.
16. Plug weld accordingly.



17. Clean and prepare welded surfaces.

Important: Prior to refinishing, refer to GM 4901MD-99 Refinish Manual for recommended products. Do not combine paint systems. Refer to paint manufacturer's recommendations. For further information or to order manual, call 1-800-269-5100.

18. Prime with two-part catalyzed primer.

Important: The rear crossbar area must be properly sealed from moisture and dirt. Seal with a full-bodied caulk such as 3D's Ultra Pro Seam Sealer (part # 08360-1). Seal both the front and the rear edges of the crossbar, as well as the inner seams.

19. Apply sealers and anti-corrosion materials as necessary.
20. Install all related panels and components.