J 42058 Frame Adapter Clamp

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

1. Disable the SIR system. Refer to SIR Disabling and Enabling in SIR.
2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.




Important: Save any and all brackets, mounting studs, and accessories for transfer to the new rear compartment panel.

3. Remove all panels and components to gain access to the rear impact bar. This includes the following components:

•	Rear bumper cover

•	Energy absorber

•

Mufflers

3.1.	Disconnect exhaust at the bolted joint just forward of the rear axle.

3.2.	From inside the vehicle remove trim panels.

3.3.	Pull back the carpeting inside the rear compartment area.

Notice: The frame rails and bumper impact bars must be serviced as required, and returned to three-dimensional coordinates before any SMC repairs are attempted.

4. Visually inspect and repair as much of the damage as possible to specifications using 3-dimensional measuring procedures. Use J 42058 if pulling and straightening of the vehicle are required. Refer to Dimensions - Body or to Measurements - Underbody .
5. Remove or reposition wiring as necessary to avoid being damaged.




Notice: Do not cut the rails when cutting windows in the rear compartment panel.

Important: The top and bottom welded edges, as well as the outer rail welds, are accessible from outside the vehicle.

6. Using a die grinder or equivalent, cut the Metal Insert Gas (MIG) welds attaching the rear impact bar to the frame rails.



7. Cut the welds around the perimeter of the frame rail (fishmouth) ends.
8. Cut the welds favoring the impact bar side of the joint. Do not cut into the frame rails.
9. To gain access to the inner rail welds, modify the rear wall of the SMC rear compartment panel in the following manner:

•	Save the cutouts for re-installation.

•	From inside the vehicle locate, mark, and cut out windows in the rear compartment panel.




10. The windows provide access to inner MIG welds attaching the impact bar to the rails.
11. Cut the remaining welds around the perimeter of the impact bar, favoring the impact bar side of the joint.



12. If necessary, apply heat, then pry apart to separate the impact bar from rear panel.

Important: Do not install the windows in rear compartment yet, welding access is necessary for installing the replacement impact bar.

13. With the rear bumper impact bar removed, repair any cracks in the SMC from outside the vehicle.

1. Straighten and deburr the rail ends as necessary to allow the service bumper impact bar to fit the rail ends properly.
2. Remove any adhesive which is cracked or broken loose from the rails or the rear compartment panel.
3. Remove the primer from the areas to be MIG welded by sanding with 80-grit paper on a Dual-Action (DA) sander. Do not use a grinder to remove the primer.
4. Prepare all bare metal surfaces and apply 3M weld-thur coating P/N 05916 or equivalent as necessary. Be sure to apply primer to the inside of the fishmouth area also.



5. Position the bumper impact bar using three-dimensional measuring equipment and weld accordingly.

5.1.	Stitch weld around the fishmouth joint.

5.2.	Make 40 mm (1 in) MIG welds along the top, bottom, and outer sides of the joint. This will create a solid weld joint with minimal heat distortion.




6. Clean and prepare all welded surfaces using 3M's Scotch-Brite Clean-N-Strip Discs (disc P/N 07460, mandrel P/N 07491), or equivalent.
7. From outside the vehicle, apply 50 mm (2 in) wide tape over the windows cut in the rear compartment panel.

Notice: Do not top coat the top surface of the impact bar where it is to be bonded to the rear compartment panel. The bonding area must remain a primer-only surface.

8. Apply structural adhesive GM P/N 89020330 or GM P/N (Canada 8902332), to the inside of the tape backer.
9. Install the previously cut-out pieces in their original locations.
10. Apply structural adhesive GM P/N 89020330 or GM P/N (Canada 8902332), to the inside of the tape backer to the entire repair area extending across the cut lines, using tacky mesh tape or an equivalent reinforcement matting.

•	Apply enough structural adhesive GM P/N 89020330 or GM P/N (Canada 8902332), to fully wet out reinforcement matting.

•	Allow to cure as necessary.

11. Scuff all bonding surfaces to ensure proper adhesion.
12. Clean and prepare all bonding surfaces as necessary.



13. Apply a bead of structural adhesive GM P/N 89020330 or GM P/N (Canada 8902332), to bond the impact bar to the rear compartment. This is a structural bond, and care must be used to ensure that the adhesive fills the gap adequately.
14. Finish and feather-edge the repair areas as necessary to resemble OEM.
15. Apply appropriate sealers. Refer to Anti-Corrosion Treatment and Repair in Paint and Coating.
16. Apply top-coat over all repaired areas. Refer to Basecoat/Clearcoat Paint Systems in Paint and Coating.
17. Install all related panels and components.
18. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
19. Enable the SIR system. Refer to SIR Disabling and Enabling in SIR.