GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Important: The redesigned frame of the 1500 model C/K pickup and C/K Utility, incorporates hydroformed technology. There is a replaceable, hydroformed, energy absorbing crush cap at the front of the frame.

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

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

  1. Disable the SIR system. Refer to SIR Disabling and Enabling .
  2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .

  3. Object Number: 383487  Size: SH
  4. Remove all of the related panels and the components.
  5. Important: If the crush cap (1) is bent or damaged in any way, replace the crush cap.

  6. Visually inspect the damage. Use 3-dimensional measuring in order to restore all of the damage rearward of the crush cap (1) to the factory specifications.
  7. Important: Do not damage the rail.

  8. Remove the core support mounting bracket (2).

  9. Object Number: 383495  Size: SH
  10. Locate the brake line attachment hole (1) on the top of the rail. Measure forward 155 mm (6 1/8 in). This is the cut line (2).
  11. Scribe a line 360 degrees around the frame rail.
  12. Important: Use caution to not damage the cross tube.

  13. Remove the crush cap at the cut-line and the forward edge of the cross tube.

  14. Object Number: 383499  Size: SH
  15. Grind the remaining weld off of the cross tube (1) where you removed the damaged crush cap.

Installation Procedure


    Object Number: 383504  Size: SH
  1. Drill 4 plug weld holes; 2 at the top and 2 at the bottom, 13 mm (1/2 in) from the cut line and 50 mm (2 in) apart on the existing frame rail (1).
  2. Prepare all mating surfaces as necessary.
  3. Apply 3M Weld-Thru Coating P/N 05916 or equivalent to all mating surfaces.

  4. Object Number: 383506  Size: SH

    Important: 

       • The replacement bumper bracket (2) is a bolt-on component that must be ordered separately.
       • Retain a gap of 1½ times the metal thickness at the butt joint (1) when attaching the service part to the vehicle.

  5. Install and position the replacement crush cap using 3-dimensional measuring.
  6. Tack weld the part into position at the initial plug weld holes.
  7. Inspect the service part for proper dimensions.
  8. Stitch weld along the entire sectioning joint. Make 25 mm (1 in) welds along the seam with 25 mm (1 in) gaps between.
  9. Complete the stitch weld.
  10. Clean and prepare the welded surfaces.
  11. 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.

  12. Apply approved anti-corrosion primer.
  13. Position the new core support mounting bracket. Weld the bracket in place according to the specified dimensions.
  14. Apply the sealers.
  15. Refinish the welded surfaces as necessary.
  16. Replace the related panels and the components.
  17. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  18. Enable the SIR system. Refer to SIR Disabling and Enabling .