64 Int. J. Heavy Vehicle Systems, Vol. 21, No. 1, 2014 Copyright © 2014 Inderscience Enterprises Ltd. Tractor-trailer modelling and validation Sahril Kushairi Faculty of Mechanical Engineering, University Technology MARA, 40000 Shah Alam, Selangor, Malaysia E-mail: sahril9810@yahoo.com.sg Reinhard Schmidt Mechanik, Maschinendynamik u. Simulation, University of Applied Sciences Osnabrueck, Osnabrueck, Germany E-mail: reinhard.schmidt@hs-osnabrueck.de Abdul Rahman Omar Faculty of Mechanical Engineering, University Technology MARA, 40000 Shah Alam, Selangor, Malaysia E-mail: aro@salam.uitm.edu.my Ahmad Azlan Mat Isa Faculty of Mechanical Engineering, University Technology MARA, 40000 Shah Alam, Selangor, Malaysia E-mail: matisaaa@hotmail.com Khisbullah Hudha Department of Mechanical Engineering, Faculty of Engineering, National Defense University of Malaysia, Kem Sungai Besi, 57000 Kuala Lumpur, Malaysia E-mail: k.hudha@upnm.edu.my Abstract: The main purpose of this project is to validate a multibody tractor- trailer model that was developed and simulated in ADAMS/Car that used tandem independent suspension system. This newly designed independent suspension takes the advantage of double wishbone concept. This article describes the modelling, experimental procedures and validation process used for a project with Gigant-group in order to obtain a validated trailer model equipped with the independent suspension. The validation process is important to ensure that the model dynamics behaviour created follows closely the