G/H VAN (GMT 610) 5 PAGE
Section 2 — Frame
Hole drilling, welding, modifications, or alterations to the frame assembly are the responsibility of persons performing these operations. These same individuals assume complete responsibility for frame assembly, reliability, performance after alterations and compliance to applicable FMVSS requirements.
The following procedures and specific precautionary instructions are recommended for proper installation of special bodies and/or equipment on GM frames. Failure to follow these recommendations could result in serious damage to the basic vehicle.
New soft mount provisions for RV and Commercial bodies (vehicles 03/32 YFI). Locations found on the reference pages 38 - 40 in the Body Builders Manual.
Flanges
Do not drill holes in frame flanges:
• Within 20 mm (0.75 in.) of radius tangent and 25 mm (1.0 in.) of raw edge.
• Larger than 12 mm (0.50 in.).
• Closer to each other than twice the hole diameter.
NOTE: The frame flanges holes recommendations might be affected by the soft mount provisions/locations.
Holes
Holes to mount brackets, supports, and out-riggers must be drilled in the vertical side web with the following restrictions:
• Material between edge of hole and inside of upper or lower flange must not be less than 37 mm (1.50 in.) for low carbon steel
(36,000 PSI yield).
• The minimum edge distance between any two (2) holes must be larger than twice the diameter of the larger hole.
• No holes should exceed 20 mm (0.75 in.) in diameter.
• All holes should be drilled in the frame using appropriate drilling practice and safety precautions.