Sectioning procedures have been developed to help simplify repair of the lower rails provided the majority of damage can be returned to factory specifications. This allows technician to repair the damage front section without the necessity of making a complete rail replacement.

Sectioning of the lower rail does not require the removal of the powertrain, although the front cradle must be lowered.

1. Remove all related panels and components.
2. Visually inspect and restore as much of the damage as possible to factory specifications.

For right side repair it may be necessary to remove the alternator and air conditioning compressor.

3. Align the appropriate inner and outer templates on the damaged lower rail and mark lines as indicated.

There are two templates for the left rail and two templates for the right rail.




4. Cut the rail along the marked lines and remove the damaged portion of the rail (1).
5. Cut and remove approximately 5 mm of the outboard and downward turned flanges of the lower rail.
6. Cut a 5 mm gap approximately 5 mm along the corners of the lower rail to create tabs (2).



7. Step the tabs inward to allow the replacement lower rail section to fit over the original rail (3).
8. Weld all four edges together.

1. Align the inner and outer templates on the service part and mark lines as indicated.

There are two templates for the new left rail and two templates for the new right rail.

2. Cut the service part along the marked lines and discard the unused section.



3. Position the modified service part over the stepped tabs of the original rail.
4. Allow 5 mm of overlap.
5. Stitch weld along the entire joint.
6. Make 25 mm (1 in) welds along the seam with 25 mm (1 in) gaps between.
7. Go back and complete the stitch weld along the seam.
8. Clean and prepare welded surfaces.
9. Apply sealers and anti-corrosion materials as necessary.

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

10. Prime with two-part catalyzed primer.
11. Install all related panels and components.