Frame Damage

The major sources of frame damage are accidents, overloading the vehicle and local overstressing due to a variety of causes. In accident cases, the reasons for the damage are readily apparent. Such damage may often be repaired by:

• Straightening and reinforcing the frame.
• Repairing the damaged area and reinforcing the frame sidemember.
• Replacing the frame sidemembers and crossmembers.

Damage to the chassis frame, such as a crack in the frame sidemember or crossmember, which is not associated with impact damage, may be an indication of overloading the vehicle. Damage to the chassis frame may also be an indication of the creation of locally high stresses due to operating conditions or equipment mounting practices. Examples of overloading are:

• Exceeding either the GVW Rating or the GAWR (Gross Axle Weight Rating) (loading the frame beyond its design capacity).
• Uneven load distribution.
• Using the vehicle in operating conditions or with equipment it was not designed for.

Examples of creation of locally high stresses are:

• Mounting bodies or equipment in a manner that causes stress concentrations and/or abrasive wear in either the flange or web portion of the sidemember.
• Improper modification or repair of frame components.
• Equipment which is susceptible to resonant vibration due to excess flexibility of its mounting.

Frame damage may also be caused by corrosion resulting from the contact between dissimilar metals.

Damage to the chassis frame, which is not associated with impact damage, should not be repaired until the cause of the damage has been determined and corrective actions taken to prevent re-occurrence of the non-impact damage.