Abstract: An electrical submersible pump assembly has modules including a pump, a motor, and a seal section. A drive shaft assembly extends from the motor through each of the modules. A threaded connection between at least two of the modules includes a first adapter having external threads and a second adapter having a neck with an external load shoulder. A collar is rotatably carried and axially movable on the neck. The collar has internal threads and an internal load shoulder. A shoulder ring having two segments encircles the neck. The shoulder ring has a first surface in abutment with the external load shoulder and a second surface in abutment with the internal load shoulder. A resilient ring tits around an outer diameter of the shoulder ring for retaining the ring segments on the neck prior to the collar being in threaded engagement with the threads of the first adapter.