Systems and methods for detecting in motion railcar seismic data generated by defective railcar axles of a train traveling on a track. The method uses two or more seismic sensors on the side of the track to capture seismic noise generated by railcar wheels. A wheel that exceeds a preset seismic noise threshold in amplitude, will trigger a wheel tracking algorithm that calculates seismic phase shift data related to the actively tracked wheel noise level, to determine the precise location, in real time, of the faulty wheel carriage while moving. Knowing the precise location of the tracked wheel allows the system to isolate the railcar and capture the railcar and wheel carriage identification information.Subsequently, a railcar log is made on a computer database with the railcar identification information and made available to control centers via ground or satellite links.