92 Ill. Adm. Code 442.440
Frame
Section 442
Section 442.440 Frame
After the date of manufacture of
the incomplete vehicle, the chassis frame shall not be altered so as to extend
the wheelbase. Other extension(s) of the chassis frame may be accomplished
only by the incomplete vehicle, intermediate, or final-stage manufacturer or by
an agent of the manufacturer properly instructed and authorized by the
manufacturer to make the extension(s).