An assembly for a bearing compartment (50A;50B;50C) of a gas turbine engine, the assembly comprising: a first shaft disposed in the gas turbine engine and co-axial with an engine centerline, wherein the first shaft comprises: an end with a radially inward facing surface; and a first threaded portion disposed on the end of the first shaft; a bearing stack disposed on a portion of the first shaft; and a spanner nut disposed on the end of the first shaft and in contact with the bearing stack, wherein the spanner nut comprises: a body; a piloting hook connected to the body, the piloting hook comprising: a first extension connected to and extending radially inward from the body; and a second extension connected to and extending in an axial direction from the first extension, wherein the second extension includes a radially outward facing surface; a second threaded portion configured to engage with the first threaded portion on the end of the first shaft; and a channel formed by the piloting hook, wherein the channel is configured to receive the end of the first shaft, characterised in that the piloting hook is configured to cause the radially outward facing surface of the second extension to contact a radially inward facing surface of the end of the first shaft. a first shaft disposed in the gas turbine engine and co-axial with an engine centerline, wherein the first shaft comprises: an end with a radially inward facing surface; and a first threaded portion disposed on the end of the first shaft; an end with a radially inward facing surface; and a first threaded portion disposed on the end of the first shaft; a bearing stack disposed on a portion of the first shaft; and a spanner nut disposed on the end of the first shaft and in contact with the bearing stack, wherein the spanner nut comprises: a body; a piloting hook connected to the body, the piloting hook comprising: a first extension connected to and extending radially inward from the body; and a second extension connected to and extending in an axial direction from the first extension, wherein the second extension includes a radially outward facing surface; a second threaded portion configured to engage with the first threaded portion on the end of the first shaft; and a channel formed by the piloting hook, wherein the channel is configured to receive the end of the first shaft, characterised in that the piloting hook is configured to cause the radially outward facing surface of the second extension to contact a radially inward facing surface of the end of the first shaft. a body; a piloting hook connected to the body, the piloting hook comprising: a first extension connected to and extending radially inward from the body; and a second extension connected to and extending in an axial direction from the first extension, wherein the second extension includes a radially outward facing surface; a first extension connected to and extending radially inward from the body; and a second extension connected to and extending in an axial direction from the first extension, wherein the second extension includes a radially outward facing surface; a second threaded portion configured to engage with the first threaded portion on the end of the first shaft; and a channel formed by the piloting hook, wherein the channel is configured to receive the end of the first shaft, characterised in that the piloting hook is configured to cause the radially outward facing surface of the second extension to contact a radially inward facing surface of the end of the first shaft.