In recent years the heavy-duty Class 8 truck market has become very focused on weight and cost reduction. This represents a major challenge for design engineers since these vehicles are used in a wide variety of vocations from highway linehaul to logging in severe off-road environments. The challenge is to meet the weight and cost reduction goals without sacrificing durability and performance. This paper discusses the integration of computer aided design and engineering software codes (Pro/Engineer, ADAMS, and ANSYS) to simulate the effect of design changes to the truck frame.In particular, this paper discuses the development of an ADAMS multi-body dynamics model of a full truck and trailer to simulate vehicle handling, roll stability, ride performance, and durability loading. The model includes a flexible frame modelled using a component mode synthesis approach with modes imported from a finite element analysis program. The link between the multi-body simulation and the finite element code is also used to transfer loads back to the finite element model for stress analysis. Tight links between all the codes ensures that new design iterations can be quickly evaluated for concurrent design and analysis. A detailed case study showing how this technology has been used is also included.