GM Service Manual Online
For 1990-2009 cars only

Reducing the concentration of stress in the small areas of the frame may often minimize of eliminate the occurrence of frame failure. The following information may assist in such a reduction:

    • Use particular vehicles only for the purpose for which they were designed.
       - Do not overload the vehicle.
       - Load the vehicle evenly.
       - Avoid any localized overloading.
       - Use baffles in all tank trucks.
       - Do not operate the vehicle on any extremely rough terrain.
    • Adhere to the following recommendations when repairing a frame and when mounting a body, or any other equipment, onto a frame:
       - Avoid any sudden changes in the section modulus.
       - Do not drill any holes in the frame rail flanges.
       - Space the holes in the web section of the rail at least 13 mm (0.5 in) apart.
       - Use existing holes whenever it is possible.
       - Do not cut the holes with a torch.
       - Do not cut any notches in the rails.
       - Do not weld on the flanges.
       - Do not allow more than 4 holes to exist on the same vertical line of the web.
       - Place any hole in a reinforcement at least 2 times the material thickness away from the edge of the reinforcement.