A remote arm for a manipulator is disclosed, which has a boom tube having a distal end and housing a mechanical communication chain. A floating gearbox assembly is coupled to the boom tube and has an outer framework rigidly coupled to the distal end of the boom tube. An inner framework is retained by the outer framework and is rotatable relative to the outer framework. A drive gear is disposed in the inner framework. which is in mechanical communication with the mechanical communication chain. A wrist joint has a wrist joint housing and an output gear is disposed in the wrist joint housing, where the wrist joint housing is configured to detachably couple to the outer framework. The output gear is configured to mechanically communicate with the drive gear when the wrist joint housing is coupled to the outer framework.