Various methods and apparatus relating to disk drive actuators and methods of manufacturing them are disclosed and claimed. In certain embodiments, a disk drive actuator assembly comprises a pivot bearing defining a pivot bearing rotational axis; an actuator arm including a bore, the pivot bearing disposed at least partially within the bore; a first tapered shim, interposed in the bore between the pivot bearing and the actuator arm, the first tapered shim having a thickness at a first end greater than a thickness at a second end; and a second tapered shim, interposed in the bore between the pivot bearing and the actuator arm, the second tapered shim having a thickness at a third end greater than a thickness at a fourth end; wherein the second tapered shim frictionally engages the first tapered shim to hold the pivot bearing substantially in place relative to the actuator arm.