Procedures

FRAME REPAIR AND REINFORCEMENT

Material:

Welding Precautions

NOTE: Whenever factory E-coat has been removed by sanding, grinding or weld burn-off, corrosion protection must be restored.

1. If welding must be done on a frame, make sure the following requirements are met:
- Prepare the vehicle for welding. For additional information, refer to Welding Precautions - Steel.
- Do not weld using gas welding equipment.
- Use a temperature-indicating crayon to make sure that the temperature does not exceed 750°C (1,400°F).
- Install new spot-welded components by spot welding where possible. If spot welding is not possible, use plug welding.

Frame Straightening

WARNING: Frame rail crush zones absorb crash energy during a collision and must be replaced if damaged. Straighten damaged frame rails to correct frame dimensions prior to frame member sectioning. Failure to follow these instructions may adversely affect frame rail performance and may result in serious personal injury to vehicle occupant(s).

CAUTION: Straightening of severely bent or kinked frame components is prohibited. However, before removing these components, restore dimensionally to a pre-collision condition.

NOTE: Whenever factory E-coat has been removed by sanding, grinding or weld burn-off, corrosion protection must be restored.

1. If heat is needed to straighten a frame member, keep the temperature below 650°C (1,200°F) (a dull red glow). A temperature sensitive thermal melt crayon of the correct temperature calibration should be used to monitor heat buildup.
- Heat should be kept to a minimum area so that the hardness of the metal will not be affected.
- Straightening should only be attempted on frames that fail to meet specifications, or where damage is apparent. For additional information, refer to Body.
- Straightening should be limited to parts which are not severely bent or kinked.
- Reposition or shield any fuel lines, brake lines or wiring harnesses or components in heated area.
- Disconnect on-vehicle modules in the immediate welding area and protect them from possible heat damage and electrical currents.

Underbody Misalignment Check

NOTE:
- Underbody misalignment can be the result of damage or loose frame components. It can affect front and rear wheel alignment and cause incorrect operation and abnormal wear of tires and chassis parts.
- For additional information, refer to Body, for dimensional data when carrying out repairs on the frame.

1. Inspect the frame for damage and loose parts before checking the frame alignment.
- Inspect all cross members for cracks, twists or bends.
- Inspect all of the welded connections for cracks.
- Check all of the support brackets for looseness.