A thrust bearing for use in downhole drilling systems employing fluid motors having a stator retaining ring and a rotor retaining ring. These rings have a plurality of bearing inserts. The bearing insert surfaces of the rotor contact the bearing surfaces of the stator. The studs which make up the bearing surface have a threaded bolt secured thereto. The threaded bolt extends through a plurality of threaded holes in each of the retaining rings. The studs and bolt may be removed or inserted by use of a simple hand tool, such as an Allen wrench.