For 1990-2009 cars

## Rear Compartment Panel Replacement Full

### Removal Procedure

1. Visually inspect and restore as much of the damage as possible to factory specifications.
2. Remove all related panels and components including gas tank and exhaust system.
3. Remove the rear trunk carpet.
4. Remove the rear seats.
5. Remove the tail panel.
6. Locate and remove two inner wheelhouse braces.
7. Identify weld locations.
8. Drill out welds through one layer of metal only
9. Remove the sealers.
10. Remove the sound deadeners.
11. Remove the anti-corrosion materials as necessary.
12. Locate factory seam at front edge of crossbar at rearward of seatback.
13. Locate and mark all factory welds.

Drill out factory welds which secure rear compartment panel to floor pan and rails, through one layer only.

14. Note the number and location of welds for installation of the service panel.
15. Drill completely through welds that attach the rear compartment to the inner wheelhouses.

Important: All rear compartment welds can be drilled out and installed to the wheelhouse area from the outside of the vehicle.

16. Remove the damaged panel.
17. Prepare mating surfaces with a suitable weld-through primer.

### Preparation Procedure

1. Lay 19 mm (3/4 in) masking tape along contour of floor pan service part where it will mate to the wheelhouse (1).
2. Notch the metal in appropriate locations at radii to allow flange to easily bend upward on the inside edge of masking tape.
3. Bend service part flange upward using suitable flanging tool.
4. Use hammer and dolly to complete preparation.
5. Create 1 inch (25 mm) downward turned flange for securing floor pan to quarter panel from end of wheelhouse to tail panel (2).
6. Drill 8 mm (5/16 in) plug weld holes at locations noted from original floor pan.

Important: In areas damaged beyond recognition, space plug weld holes every 40 mm (1 ½ in) apart.

7. Prepare mating surfaces for welding.

### Installation Procedure

Important: Carefully bend but do not crease the front corners of the new panel to allow it to fit between the inner wheelhouses.

1. Position the service floor pan.
2. Check for proper fit according to body dimensions and clamp in place.
3. Plug weld accordingly.
4. Install both inner wheelhouse braces.
5. Clean and prepare all 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.

6. Apply an approved anti-corrosion primer.
7. Apply a full-bodied caulk, to form a consistent, leak-proof seal around perimeter of rear compartment panel (2).
8. Refinish as necessary.
9. Install all related panels and components.

## Rear Compartment Panel Replacement Pan Overlap

### Removal Procedure

Important: It is recommended that Full Replacement Procedure is performed for full rail replacement.

1. Visually inspect and restore as much of the damage as possible.
2. Remove all related panels and components including fuel tank.
3. Remove both inner wheelhouse braces.
4. Identify weld locations.
5. Drill through one layer of metal only.
6. Remove the sealers.
7. Remove the sound deadeners.
8. Remove the anti-corrosion materials as necessary.
9. Apply a one-inch piece of masking tape to the damaged rear compartment panel from the joint at the floor pan to the rear edge of the wheelhouse, along the entire contour of both sides of the rear compartment.
10. Cut along the inboard side of tape to create a weld flange.

Important: Do not damage rail or reinforcement.

11. Locate factory seam at the front edge of the crossbar, rearward of seat back.
12. Locate, and mark all factory welds which secure rear compartment to rails. Note the number and location of welds for installation of the service panel.
13. Drill welds out through one layer of metal only.
14. Remove the damaged section.

### Preparation Procedure

1. Lay 19 mm (¾ in) masking tape along the contour of the service part where it will mate to the wheelhouse (1).
2. Cut along the inboard side of the tape and remove unused portion of the floor pan.
3. On rear section of the service part, from end of wheelhouse to tail panel, create a 1 inch (25 mm) downward-turned flange (2).

Important: Area of overlap must have plug weld holes spaced every 40 mm (1½ in) apart.

4. Drill 8 mm (5/16 in) plug weld holes as necessary in areas noted from original locations in floor pan.

### Installation Procedure

Important: Carefully bend but do not crease the front corners of the modified service part to allow it to fit between the inner wheelhouses (1).

1. Prepare mating surfaces with suitable weld-through primer.
2. Position the service floor pan.
3. Check for fit and clamp in place.
4. Plug weld accordingly.
5. Reinstall both inner wheelhouse braces.
6. Clean and prepare all 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

7. Apply an approved anti-corrosion primer.
8. Apply a full-bodied caulk to form a consistent, leak-proof seal around perimeter of rear compartment panel (2).
9. Refinish as necessary.
10. Install all related panels and components.