GM Service Manual Online
For 1990-2009 cars only

Note: If the damage exceeds the recommended area for sectioning and the rail cannot be straightened, the complete rail must be replaced.

Sectioning procedures have been developed to simplify repair of the lower rails, providing the majority of the damage can be returned to factory specifications.

Failure to follow the instructions may lead to improper rail sectioning, which may compromise the structural integrity of the vehicle. Be certain to use correct procedure for proper rail sectioning. Left and right side rails have different cut measurements.

Removal Procedure

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

  1. Disable the SIR system. Refer to SIR Disabling and Enabling.
  2. Disconnect the negative battery cable.

  3. Object Number: 2020734  Size: SH
  4. Remove all related panels and components.
  5. Restore as much of the damage as possible to factory specifications. Refer to Dimensions - Body.
  6. Warning: Refer to Foam Sound Deadeners Warning in the Preface section.

  7. Note the location and remove the sealers and anti-corrosion materials from the repair area as necessary, Refer to Anti-Corrosion Treatment and Repair.
  8. Perform the necessary procedures to gain access to repair. Refer to Radiator Support Replacement , Tie Bar Replacement - Left Side , Lower Tie Bar Replacement.

  9. Object Number: 2020690  Size: SH
  10. Locate, mark, and drill out all factory welds attaching the left front lower rail section.
  11. On the top of the rail, locate the middle cut-out hole (1). From the middle of the cut-out hole, measure forward 150 mm (5.91 in) and scribe a line, this is the cut location (2).

  12. Object Number: 2020691  Size: SH
  13. Locate, mark, and drill out all inner factory welds attaching the left front lower rail section.

  14. Object Number: 2020692  Size: SH
  15. Locate, mark, and drill out all lower factory welds attaching the left front lower rail section.
  16. Remove the damaged section of the rail.

Service Part Preparation

  1. Clean and prepare mating surfaces as necessary.
  2. Apply 3M® Weld-Thru coating P/N 05916 or equivalent to all mating surfaces
  3. Drill 8 mm (5/16 in) plug weld holes, as necessary, in the locations noted from the original assembly.

Installation Procedure

  1. Position the service part over the original rail.
  2. Align and check fit with 3-dimensional measuring. Refer to Dimensions - Body.

  3. Object Number: 2020702  Size: SH
  4. When the service assembly is correctly positioned, plug weld accordingly (1).
  5. Stitch weld along the entire sectioning joint (2).
  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 to create a solid weld joint with minimal heat distortion.

  8. Object Number: 2020703  Size: SH
  9. Complete the remaining plug welds on the front lower inner side of the rail.

  10. Object Number: 2020705  Size: SH
  11. Complete the remaining plug welds on the lower side of the left rail.
  12. Complete the necessary procedures. Refer to Radiator Support Replacement , Tie Bar Replacement - Left Side , Lower Tie Bar Replacement.
  13. Clean and prepare all welded surfaces.
  14. Apply the sealers and anti-corrosion materials to the repair area, as necessary. Refer to Anti-Corrosion Treatment and Repair.
  15. Paint and repair the area. Refer to Basecoat/Clearcoat Paint Systems.
  16. Install all related panels and components.
  17. Connect the negative battery cable.
  18. Enable the SIR system. Refer to SIR Disabling and Enabling.