GM Service Manual Online
For 1990-2009 cars only

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

Caution: Refer to Collision Sectioning Caution in the Preface section.

Important: When determining the area to perform the sectioning near a riv-nut within the recommended areas, choose a location that centers the sleeve through the hole. This will ensure that riv-nut fasteners remain straight during installation.


    Object Number: 857910  Size: SH
  1. From the new section of frame rail, measure, mark, and cut 50 mm (2 in) of frame rail to be used as a sleeve (backing plate) for the sectioning joint.
  2. Cut through each side of the sleeve to create four individual L-shaped pieces that can be installed in the new frame rail section.
  3. Install the four pieces, one at a time.
  4. Trim the pieces as necessary, to provide a flush fit along the inner surface of the new frame rail section.
  5. Clean and prepare all of the welded surfaces.
  6. Apply 3M weld-thru coating P/N 05916 or equivalent as necessary.
  7. Using a Metal Inset Gas (MIG) welder, tack weld the four pieces to the inner surface of the new frame rail section.
  8. Grind the sleeve as necessary to allow for accurate alignment of the existing frame rail.

  9. Object Number: 858110  Size: SH
  10. Install the new frame rail section to the existing frame rail to create the butt joint while maintaining a gap of one and one half frame rail metal thickness at the sleeve butt-joint.
  11. Inspect the new frame rail section using three-dimensional measurements. Refer to Dimensions - Body .

  12. Object Number: 858113  Size: SH

    Important: Use a 25 mm (1 in) stitch weld to avoid minimal heat distortion.

  13. Using a MIG welder, weld completely around the sleeve joint.