Rear Roof Perforation (Install New Rear Roof Section)

This bulletin is being revised to add Warranty information. Please discard Corporate Bulletin Number 01-08-66-011B (Section 08 -- Body and Accessories).

Important: Implementation of this Service Bulletin by "GM of Canada" dealers requires prior District Service Manager approval.

Some customers may comment that the rear portion of the roof has some rust forming. This condition mainly happens in coastal states.

During production, the E-coating may have missed that portion of the roof.

Replace the rear roof section following the procedure listed below.

1. Remove the following components depending on the model (See Illustration):

•	Luggage rack

•	Third brake light

•	Left and right interior quarter panel trim

•

Headliner

•	Rear lift gate primary seal

•	Lift gate or lift glass




2. FOR 4 DOOR VEHICLES, measure 55 mm (2 3/16 in) forward of the downturn flange, and mark the cut line the width of the vehicle roof as shown using a tape measure or scale (See Illustration).

FOR 2 DOOR VEHICLES, measure 65 mm (2 1/2 in) forward of the downturn flange, and mark the cut line the width of the vehicle roof as shown using a tape measure or scale (See Illustration).




3. Mark a line from the line to the rear downturn flange on the left and right side of the vehicle (See Illustration).




Important: While performing this next step, cut through one layer of metal only.

4. Cut along the marked lines.



5. Use a grinder or equivalent tool in order to grind away the rear radius of the roof.



6. Remove the damaged roof section.




Important: While performing this next step, drill through the roof reinforcement only.

7. Locate and drill approximately 12 spot welds along the rear roof reinforcement.



8. If necessary, use a chisel in order to separate the roof reinforcement from the mating surface.

Important: 

•	Bonding surfaces must be ground clean of material to the bare metal.

•	Cover and protect the surrounding surfaces from sparks.

9. Grind all mating edges to which the adhesive will be applied.



10. Grind a taper to the existing roof seam at a 10 degree angle 7 mm (1/4 in ) wide (Knife edge the roof ).



11. Grind the underside of the existing roof.



12. Grind the top surface of the D-Ring.



13. Grind the TOP and BOTTOM of the service part mating edges to bare metal.




•	Dry fit the new part to the body.

•	While the part is attached to the body, mark the bottom side of the new part in order to determine which area needs to be ground to bare metal.

•	Remove the part from the body and grind the bottom side of the part to bare metal.

•	Thinly coat all bare sheet metal on the bottom side of the part with adhesive.





Important: Pre-fit the service part to ensure proper alignment.

14. Apply two 10 mm (3/8 in) beads of adhesive along the entire prepared surface on the vehicle.



15. Apply a 10 mm (3/8 in) bead of adhesive along the service parts edge.

Important: When the service panel has been positioned, do not lift the panel away from the vehicle. If repositioning is necessary, slide the panel only. This maintains proper contact between the two panels.

16. Install the service part to the vehicle in proper alignment to the original location.



17. Clamp the roof down with very light pressure. Spread the load by putting paint sticks under the clamps.
18. Wipe any excess adhesive from the panel before the adhesive cures.
19. Allow the adhesive to cure for 1½ to 2 hours. Expect the adhesive to be "tacky" on the surface. This is normal. Clean the sheet metal and adhesive surface with a solvent wipe.
20. Remove any remaining adhesive where body filler will be applied.
21. Apply a fiberglass filled body filler to the sectioned area for your first coat. Let cure then sand.
22. Apply a lightweight body filler to the sectioning locations for your second coat. Cure and sand. Additional coats may be required.
23. Drilling will be necessary for third brake lamp if equipped.

Important: Prior to refinishing, refer to publication GM4901M-D (GM4901M-D-F for French), GM Approved Refinish Materials Guide for recommended products. Do not combine paint systems. Refer to the paint manufacturer's recommendations.

24. Apply an approved anti-corrosion primer.
25. Apply sealers and refinish as necessary.
26. Seal the underside seams with body seam sealer.
27. Install all related panels and components.

To order the applicator for the adhesive, call GM TOOLS phone number 1-800-468-6657, press #2. The applicator part number is 310 - 301.

Parts are currently available from GMSPO.

For vehicles repaired under warranty, use: