Mechanical systems are mainly considered in heavy transmissions, and helix-angled gears are being mostly used in such fields of interest. As these mechanical components operate, they are heavily subjected to potential faults of operation. To avoid experimental faults, simulation-based analysis and test apparatus are now used for diagnosing purposes and hence, improving the dependability while enhancing their performance. For that, this paper presents an integrated approach of simulation analysis and the fabrication of a test rig specifically designed for fault inducing and seeding in helical gear transmissions. Computer-aided design and engineering techniques are both used to conduct vibration-based analysis. Six mode shapes are called out for in the modal simulation workbench where they were discussed accordingly. Bearing-mounted accelerometers were used to capture vibration signals of three operating axis in order to study the potentiality of utilizing them for condition monitoring. The current approach has demonstrated advancements in fault diagnosis methodologies and provided valuable insights in enhancing reliability and dependability of such applications.