Seamless integration of our vehicles with Truck Equipment Manufacturers is essential to the success of every business we support. With our TEM/Body Builder resources, we provide direct access to the essential information our partners need to design and build the most complete solutions for every customer. From technical service information (TSI) letters and circuit diagrams to software and FAQs, the Navistar® Body Builder Resource Center assists truck equipment manufacturers (body builders) with guidance and support for all International trucks and their vital components.