A shaft assembly includes a shaft, a nut, a nut lock ring and a tubular nut support ring. The shaft includes a nut base mounted on the shaft, and a plurality of protrusions that extend radially out from the nut base. Adjacent protrusions are circumferentially separated by a gap. The nut lock ring includes a tubular ring base connected axially between a plurality of first lock tabs and a plurality of second lock tabs. The ring base is disposed on the nut base. Each first lock tab extends radially inward through a respective one of the notches. Each second lock tab extends axially through a respective one of the gaps. The nut support ring is disposed on the ring base.