Frame Repair and Reinforcement
Frame Repair and Reinforcement
General Equipment
Material
Welding Precautions
WARNING: Before servicing a vehicle equipped with a fire suppression system, depower the system by following the procedure in Fire Suppression System. Failure to follow the instructions may result in serious personal injury.
WARNING: Invisible ultraviolet and infrared rays emitted in welding can injure unprotected eyes and skin. Always use protection such as a welder's helmet with dark-colored filter lenses of the correct density. Electric welding will produce intense radiation, therefore, filter plate lenses of the deepest shade providing adequate visibility are recommended. It is strongly recommended that persons working in the weld area wear flash safety goggles. Also wear protective clothing. Failure to follow these instructions may result in serious personal injury.
WARNING: Always wear protective equipment including eye protection with side shields, and a dust mask when sanding or grinding. Failure to follow these instructions may result in serious personal injury.
NOTE: Whenever factory E-coat has been removed by sanding, grinding or weld burn-off, corrosion protection must be restored. For additional information, refer to Restoring Corrosion Protection Following Repair.
1. If welding must be done on a frame, make sure the following requirements are met:
^ If the frame is attached to the vehicle, the battery ground cable must be disconnected before using any electrical welding equipment. For additional information, refer to Battery and Charging System.
^ Do not use 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).
NOTICE: Straightening of severely bent or kinked frame components is prohibited. However, before removing these components, restore dimensionally to a pre-collision condition. For additional information, refer to Body.
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 (1,2OO°F) (a dull red glow). A temperature sensitive thermal melt crayon 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.
^ Reposition or shield any fuel lines, brake lines or wiring harnesses or components in heated area.
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.
NOTE: 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.