This paper presents an improved CBM (Condition-based-Maintenance) framework for freight locomotives maintenance that can be implemented to either complement or completely replace any conventional TBM (Time-Based Maintenance) approach adopted by the rail freight industry today. The foundation and most significant component of this framework is the critical review of; the existing TBM regime, and the historical failure data using techniques such as Pareto Analysis and FMEA (Failure Mode & Effect Analysis). Once the critical review is completed, the improved framework experimentation and implementation stages can begin, which consist of the deployment of sensors and CBM techniques to detect anomalies on the locomotive systems and subsystems by fusion or separate monitoring of parameters such as vibration and temperature. An example of the framework application in the critical review stage is included in this paper using real locomotive failure data. The paper concludes with suggested future work to enable transition from TBM to CBM with focus on components with the greatest impact on cost and the organization’s profitability at the time of this study.