Removal Procedure
Important: The front upper rail is serviced as two components: inner (1) and outer
(3) panels. The outer panels is serviced as a sub-assembly which includes
an inner reinforcement (2). After the outer rail has been removed, the inner
rail is completely accessible and can be serviced at the factory seams.
Important: Sectioning of the front upper rails is not recommended.
- Remove all related panels and components.
- Remove sealers and anti-corrosion materials as necessary.
- Locate, mark, and drill out all factory welds attaching the outer rail.
- Remove the damaged outer rail (3).
- Locate, mark, and drill out the welds attaching the inner rail
(1).
- Remove the damaged inner rail.
Installation Procedure
- Prepare the mating surfaces as necessary.
- Drill 8 mm (5/16 in) plug weld holes as necessary in the locations
noted from the original panels.
Important: If original locations are damaged beyond recognition, locate holes for
plug welding 40 mm 1½ in) apart.
- Temporarily position the inner and outer rails on the vehicle.
- Using three-dimensional measuring equipment, locate
and mark front fender mounting bolt holes in the outer rail.
- Drill 5.5 mm (7/32 in) holes for self-tapping bolts
as marked.
- When the service panels are correctly
positioned, remove the outer panel and plug weld the inner panel as necessary.
- Reposition the outer rail with frequent measurements
to ensure proper fit and alignment.
- Plug weld accordingly.
- Clean and prepare all welded surfaces.
- Prime with two-part catalyzed primer.
- Apply sealers and anti-corrosion materials as necessary.
Important: Prior to refinishing, refer to GM4901-MD Refinish Manual for recommended
products. Do not combine paint systems. Refer to paint manufacturer's recommendations.
- Install all related panels and components.