GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Oldsmobile 🢒 1999 🢒 Aurora 🢒 Body and Accessories 🢒 Collision Repair 🢒 Upper Rail Replacement

Removal Procedure
  1. Remove all related panels and components.
  2. Visually inspect and restore as much of the damage as possible to factory specifications.
  3. Remove the following as necessary:
    4. • sealers
    • sound deadeners
    • anti-corrosion materials
  4. Note the number and location of weld for installation of the new rail.

    5. Important: Care must be taken not to damage the flanges.


    Object Number: 408785 Size: SH
  5. Separate the floor pan reinforcement vertical flanges from the inside of the lower rails.
  6. Drill out the factory welds along the lower flanges on the floor pan reinforcement.

    7. Important: Note that the flanges overlap the rails.

  7. Use a 8 mm (5/16 in) drill bit.
  8. Turn the lower flanges down on an angle away from the rail.
  9. Drill out the remaining factory welds on the rail.
  10. Drill out and remove the lower portion of the rail at the wheelhouse.
  11. Loosen the adhesive between the floor pan and lower rail with a flat chisel by prying the rail away from the floor. Take care not to damage the floor.

Installation Procedure
  1. Prepare mating surfaces for proper fit of the new rail.

    2. Object Number: 408785 Size: SH
  2. Turn the vertical flanges forward to be welded to the new rails.
  3. Drill the same number of 8 mm (5/16 in) holes on the new rail in the remaining locations as noted from the original rail.
  4. Position the new rail in place and check for proper alignment.
  5. Remove the rail to clean and prepare all surfaces.

    6. Important: Prior to refinishing, refer to GM P/N 4901MD Refinish Manual for recommended products.

  6. Prime surfaces in the same locations as the original adhesive.
  7. Apply GM Goodwrench structural bonding epoxy P/N 12345726 to the rail in the same location as the original adhesive.
  8. Position the new rail in place and secure.
  9. Let adhesive cure for one hour before welding.
  10. Position the down turned flanges to their original location in the new rail.
  11. Plug weld in random formation until all welding is completed.
  12. Clean and prepare welded surfaces.
  13. Apply sealers and anti-corrosion materials as necessary.
  14. Apply Dominion Sure Seal paintable sound deadening pad P/N 110900 to the floor as necessary to match the original sound deadening.

    15. Important: Prior to refinishing, refer to GM P/N 4901MD Refinish Manual for recommended products.

  15. Prime with two-part catalyzed primer.