A rack drive assembly adapted for use in a vehicle electric power steering assembly includes a bearing assembly disposed in a rack housing and carried by a ball nut assembly for rotatably supporting the ball nut assembly relative to a steering member; and a spanner nut carried by the rack housing for securing the bearing assembly in the rack housing. A first isolator, a second isolator and a first shim are provided wherein the first isolator is disposed between an inner surface of the housing and a first surface of an outer race of the bearing, the second isolator is disposed between an opposite second surface of the outer race of said bearing and the first shim, the first shim is disposed between the second isolator and the spanner nut. The first shim is provided with a member configured to be coupled to the housing to allow for axial movement but prevent rotational motion of the shim during installation of the spanner nut.