An electrical submersible pump assembly comprising a first section and a second section with an outer housing and a drive shaft. A coupling assembly comprising a coupling, a thrust pin, and a retainer ring mechanically couples the first drive shaft to the second drive shaft. The coupling is generally cylindrical in shape with splines formed along the inner surface configured to transfer torque from the first shaft to the second shaft. The thrust pin is installed in a pin bore in the lower shaft and extends into a retainer bore in the upper shaft. The retainer ring is installed between a groove in the retainer bore and a retainer groove on the outside of the thrust pin. The thrust pin is configured to transfer tensile stress from the retainer bore in first drive shaft to the pin bore in the second drive shaft.