GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2007 🢒 Grand Prix 🢒 Preface 🢒 Cautions and Notices 🢒 Front Wheelhouse Replacement

Removal Procedure
Object Number: 1546664 Size: SH

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

Caution: Refer to Foam Sound Deadeners Caution in the Preface section.

Important: 

   • Model year 2004 and prior vehicles are not manufactured with laminated steel in front of the dashes. Therefore, the front wheelhouse assembly can be metal inert gas (MIG) welded instead of the rivet and bonding process, as stated in these instructions.
        The front of the dash panel is formed from laminated steel. This steel is constructed by bonding 2 pieces of cold rolled steel (1) with a viscoelastic layer of adhesive (2). MIG welding laminated steel does not meet GM Corporate standards for structural integrity. As an alternative, all factory welds will be replaced by using the rivet and adhesive bond method described in the installation portion of this procedure. The rivet and adhesive bond method must only be used in the areas, as described in this procedure.
   • Failure to follow this procedure will compromise the structural integrity of the vehicle.

  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. Caution: Refer to Collision Sectioning Caution in the Preface section.

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

    6. Object Number: 1546678 Size: SH

    Important: Note the number and location of the factory welds for installation of the full wheelhouse service part.

  6. Remove the radiator support assembly. Refer to Radiator Support Replacement .
  7. Remove the upper fender rail. Refer to Upper Rail Replacement .

    8. Object Number: 1546539 Size: SH

    Important: Drill through the wheelhouse flange only. Do NOT drill into the dash panel or the inner reinforcements.

  8. Using an 8-mm (5/16-in) spot weld remover, locate and drill out the factory welds on the weld flange connecting the wheelhouse to the dash panel.

    9. Object Number: 1546556 Size: SH
  9. Remove the wheelhouse.

Installation Procedure

    Object Number: 1546544 Size: SH
  1. Position the service wheelhouse to the vehicle using 3-dimensional measuring equipment.
  2. Clamp the wheelhouse in place.

    3. Object Number: 1546580 Size: SH
  3. Using a 7-mm (17/64-in) bit, drill the rivet attachment holes through the service wheelhouse and the dash panel, in the exact locations as noted from the factory wheelhouse.

    4. Object Number: 1546556 Size: SH
  4. Remove the service wheelhouse.

    5. Object Number: 1546581 Size: SH

    Important: If the location of the original plug weld holes cannot be determined, space the plug weld holes every 40 mm (1.5 in) apart.

  5. Drill 8-mm (5/16-in) plug weld holes in the service wheelhouse, as necessary, in the remaining locations noted from the original wheelhouse.
  6. Prepare the plug weld mating surfaces, as necessary.
  7. Apply GM-approved weld-thru coating or equivalent to the plug weld mating surfaces. Refer to Anti-Corrosion Treatment and Repair .

    8. Object Number: 1546582 Size: SH
  8. Prepare the bond mating areas by grinding the body mating and the service part flanges to bare steel. Do NOT damage the corners or thin the metal during the grinding process.
  9. Clean the mating surfaces.

    10. Object Number: 1546583 Size: SH

    Important: The adhesive has a 40-50 minute working time. Do NOT allow the adhesive to cure prior to installing the service wheelhouse.

  10. Apply a 3-6 mm (1/8 to 1/4 in) bead of metal panel bonding adhesive GM P/N 12378567 (Canadian P/N 88901675) or equivalent to both of the mating surfaces.

    11. Object Number: 1546584 Size: SH
  11. Using a small acid brush, spread a coat of adhesive to both of the mating surfaces. Cover all of the bare metal to ensure corrosion protection.

    12. Object Number: 1546585 Size: SH
  12. Apply a 3-6 mm (1/8 to 1/4 in) bead of metal panel bonding adhesive GM P/N 12378567 (Canadian P/N 88901675) or equivalent to the mating surface of the service wheelhouse.

    13. Object Number: 1546544 Size: SH

    Important: Do NOT pull the wheelhouse off of the dash after adhesion. To align the parts, slide the wheelhouse against the front of the dash.

  13. Position the service wheelhouse to the vehicle using 3-dimensional measuring equipment.
  14. Clamp the wheelhouse in place.

    15. Object Number: 1546586 Size: SH

    Important: Verify proper positioning of the service wheelhouse prior to riveting and welding.

  15. Install the 9 mm (11/32 in) long rivets so that the rivet head contacts the passenger compartment side of the dash.
  16. Remove the excess adhesive from the wheelhouse area.

    17. Object Number: 1546587 Size: SH
  17. Plug weld the remaining holes accordingly.
  18. Clean and prepare all of the welded surfaces.
  19. Install the radiator support assembly. Refer to Radiator Support Replacement .
  20. Install the upper fender rail. Refer to Upper Rail Replacement .
  21. Apply the sealers and anti-corrosion materials to the repaired area, as necessary. Refer to Anti-Corrosion Treatment and Repair .
  22. Paint the repaired area. Refer to Basecoat/Clearcoat Paint Systems .
  23. Install all of the related panels and components.
  24. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  25. Enable the SIR system. Refer to SIR Disabling and Enabling .