A mechanical transducer probe assembly is provided which is both rugged and easy to assembly. The probe mechanism is located inside a hollow probe case. A reference point for assembly is located on the inner surface of the case. A motor assembly and a transducer mounting assembly are located within the case and are fixedly joined together. At the jointure of the two, the motor and transducer assemblies are in contact with the reference point, thereby positionally locating the transducer and its drive mechanism within the case. Means are provided for urging the motor and transducer assemblies against the references point, which means also provides shock mounting for the probe mechanism.