A submersible well fluid pump has diffusers non-rotatably mounted in a pump housing. A drive shaft rotates an impeller between each of the diffusers. A bearing is positioned between and in abutment with two of the diffusers. An annular recess encircles an outer wall of the bearing. A wave spring has undulations with inward protruding indentations in contact with a base of the recess and outward protruding indentations in engagement with an inner wall of the housing. The wave spring is split and radially compressed between the base of the recess and the housing inner wall.