Metro Trains Melbourne (MTM) strives to provide a safe, reliable and available passenger rail service throughout the metropolitan network, through the delivery of over 14,000 services each week utilising 3 different rolling stock fleets. Through customer feedback and identification of prematurely wearing bogie components, the Comeng vehicles fitted with BradKen cast frame bogies exhibited poor ride quality at speeds higher than 100 km/h, which was being exacerbated by increased passenger loading. This led to an investigation of the ride quality, the objective of which was to identify the reasons behind the poor ride quality and to improve the dynamic performance of the vehicle, making for a more comfortable ride for commuters and a reduction in maintenance costs. In-service testing was initiated by instrumenting a trailer bogie on a revenue train to identify the severity of the poor ride quality and any potential correlation to geo-locations. This exercise identified the root causes and potential configuration changes necessary for the bogie. A computer model of the bogie was developed and multi-body simulations carried out using Universal Mechanism (UM, www.umlab.ru) to identify potential solutions to improve the ride performance, the basis of which was validating the computer model simulation results with the inservice test results. Multiple simulation iterations led to the identification of the appropriate configuration change by varying the primary vertical damping rate. Further field testing was carried out to validate the simulation predictions. This paper discusses the testing, analysis and modelling methods used, and some of the innovative approaches explored, to identify and rectify the bogie's poor dynamic behaviour.