A backing ring that serves to back an antifriction bearing on the journal of a rail car axle includes an annular body that seats against a fillet that is located at the end of the journal and also a lip that projects over a larger dust guard diameter that is located on the axle immediately beyond the fillet. In addition, the backing ring includes a stabilizing element which cooperates with the lip and with the dust guard diameter to lessen the tendency of the annular body to work against the fillet and create a fretting wear when the journal undergoes cyclic flexures. The stabilizing element accommodates dust guard diameters of varying size. The stabilizing element may also establish a seal between the lip and the dust guard diameter.