A method of detecting motion in a load bearing member on a machine. The method includes positioning a Doppler radar detector on the machine and orienting the Doppler radar detector such that the Doppler radar detector floods the load bearing member transmitted radio frequency signals. The method further includes receiving reflected radio frequency signals from the load bearing member with an antenna and generating intermediate frequency signals based on differences between the transmitted radio frequency signals and the reflected radio frequency signals. The method further includes measuring the intermediate frequency signals.