This article was published in the
June 2013 edition of NTEA News
Question: We are an
upfitter and want to make sure we’re installing our bodies correctly. Are there
any resources available to upfitters that offer information on body
mounts?
Answer: Neither the
U.S. Department of Transportation’s Federal Motor Carrier Safety Administration
or the National Highway Traffic Safety Administration provides regulations or
standards regarding body mounting. Instead, your primary sources for body
mounting procedures are the body manufacturers and chassis
manufacturers.
The body type, stiffness,
application/vocation, duty cycle and chassis gross vehicle weight rating (GVWR)
are all contributing factors in determining the method of attachment to the
chassis. Following are the most common attachment methods, but the OEMs will
provide more details in their body builder information (note that the amount of
information shared by each chassis manufacturer will vary).
- U-Bolt/Threaded Rod and End
Plate — Secures the body’s longitudinal mounting rail to
the chassis frame. A filler of wood, rubber or plastic is recommended between
the longitudinal mounting rails and the chassis frame. When u-bolts/threaded end
plates are used, at the rear end of the body, a shear plate is utilized to
eliminate fore and aft movement of the body.
- Brackets and Pinch
Bolts — The brackets, which are fabricated, formed or
angled, are welded or bolted to the body’s longitudinal mounting rail and bolted
to the chassis frame. A bolt is used to “pinch” or secure the two brackets or
angles together.
- Hard Attachment —
Attachment to the top frame flanges utilizing the holes provided by the chassis
manufacturer for mounting OEM pickup boxes, intended for vehicles under 15,000
lbs. GVWR with service/utility bodies.
Most chassis manufacturers publish a body
builder manual that includes detailed instructions and graphics for mounting
various body styles. Some OEMs also provide information on body subframe design
and construction, subframe crossmembers and sill plates. Some body builder
manuals are published annually, while others carry over into subsequent model
years and are updated as needed. Many chassis manufacturers also maintain body
builder information for previous model years.
NTEA.com Chassis Manufacturer
Directory
The NTEA maintains an online Chassis Manufacturer
Directory, which lists OEM sales and technical contact information as well
as links to additional documents and resources, including body builder manuals.
To access the Directory, visit the “Technical Resources” area of
NTEA.com. Login information is required to access the technical
contacts.
For personalized login assistance,
contact Luci Pfaff, NTEA membership manager, at 1-800-441-6832, ext. 128, or
luci@ntea.com.