Lower Rail Replacement Full Replacement

Important: The lower rail service part comes as a complete unit, including all brackets and reinforcements.

1. Remove all panels and components necessary for access.
2. Restore as much of the damage as possible to factory specifications.




Important: Inner and outer sectioning templates are available for both the left and right rails. It is important to use the correct template when marking lines for cutting.

3. Align the appropriate inner and outer templates on the damaged lower rail and mark lines as indicated.
4. Cut the rail along the marked lines.
5. Remove the damaged portion of the rail.



6. Cut and remove approximately 5 mm (1/4 in) of the outboard and downward turned flanges of the lower rail.
7. Cut a 5 mm (1/4 in) gap approximately 5 mm (1/4 in) along the corners of the lower rail to create tabs.



8. Bend the tabs inward to allow the replacement lower rail section to fit over the original rail.
9. Weld all four edges together of rail at cut corners.

1. Align the inner and outer templates on the service part and mark lines as indicated.
2. Cut the service part along the marked lines. Discard the unused section.



3. Position the modified service part over the stepped tabs of the original rail, allowing 5 mm (1/4 in) of overlap.
4. Prepare all mating surfaces as necessary.
5. Apply 3M Weld-Thru Coating P/N 05916 or equivalent to all mating surfaces.
6. Stitch weld along the entire joint. When stitch welding, make 25 mm (1 in) welds along the seam with 25 mm (1 in) gaps between.
7. Complete the stitch weld along the seam.

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.

8. Apply as necessary:

•

Sealers

•	Anti-corrosion materials

•	Two-part catalyzed primer

•

Top-coat

9. Install the panels and components previously removed for access.