GM Service Manual Online
For 1990-2009 cars only

    Object Number: 861293  Size: MF

    Important: Only the outer longitudinal rail may be sectioned in the area specified. Repair and restore as much structure as possible before cutting and preparing the joint for welding. No reinforcements may be sectioned. The joint cut line is located at 40 mm (1-37/64 in) rearward of the 5-bar extension flange. The reinforcement must be welded to the new rail section. This may be accomplished by using a screw to draw the 2 layers together. This hole will need to be plug welded when the layers are attached.

  1. Note the amount and location of the spot welds.
  2. Remove the sealer and drill spot welds from the areas necessary to place the joint in the areas specified.
  3. Cut the service part along the joint area. DO NOT damage the inner reinforcements.
  4. Clean all of the weld seams with a wire brush, prime, and seal all repair areas.
  5. Apply a permanent underbody sealant.
  6. Important: Ensure that proper corrosion protection processes are used on all repair areas.

  7. Prime with a 2-part catalyzed primer.
  8. Apply sealers and corrosion protection materials according to the information in the Body Paint section of this service manual or the paint manufacturer's recommendations.
  9. Important: To ensure a secure weld, the sectioning joint should have a gap of approximately one and a half times the thickness of the metal. Trim the parts as necessary to achieve this.

  10. Perform any additional procedures as necessary to remove the unused areas of the service part.
  11. Drill 8 mm (5/16 in) plug weld holes as necessary in the locations noted from the original section.
  12. Clean the surface for welding and grind the Elpo primer off of the new part at the connecting points.
  13. Apply 3M® Weld-Thru Coating P/N 05913, or equivalent, to all areas to be welded.
  14. Stitch weld along the entire joint. Make 25 mm (1 in) gaps between.
  15. Go back and complete the stitch weld. This will create a solid joint with minimal heat distortion. Refer to Space Frame Sectioning .