Abstract: A pump has a packing nut extending into an open end of the plunger bore and a device coupled to the packing nut. The device includes first body coupled to a second body to form a body of the device. A first post connected to the body and a second post connected to the body. The first post extending into a first opening of the packing nut and the second post extends into a second opening of the packing nut to couple said device to said packing nut. A stop forms a portion of the device. When the body is in a locked orientation, the stop of the device abuts or will abut, when the nut is rotated in a loosening direction, a connecting assembly of the pump. When the body is in the unlocked orientation, the second post is moveable, relative to the first body and the first post, in a direction out of the second opening, and a first portion of said second body, exclusive of said second post, is moveable in a direction relative to said first body and first post.