A method of adjusting backlash in a down hole bearing assembly involves providing in side by side relation on an outer surface of an inner mandrel a circumferential first threaded seat adapted to accommodate a first nut which engages the first threaded seat by rotation in a first rotational direction and becomes disengaged by rotation in a second rotational direction and a circumferential second threaded seat adapted to accommodate a second nut which engages the second threaded seat by rotation in the second rotational direction and becomes disengaged by rotation in the first rotational direction. The first nut is threaded onto the first threaded seat to place the inner mandrel in tension with a first stop and a second stop engaging a thrust bearing. The second nut is coupled to the first nut to resisting any rotational movement of the first nut in the second rotational direction.