1.VerbTo make something true, equal, or correct, as for example by turning and facing a part on a lathe.
"He trued up his faceplate before doing the next setup.; He trued up the brake discs and installed new pads."
2.VerbTo make a wheel level, balanced or even by adjusting the spokes; to true a wheel; ideally, to make it perfectly circular in relation to the hub with no left or right bulges nor 'flat spots'.