The Toyota Knuckle Alignment Tool is finally here! It is important to know what shims to run when rebuilding your front knuckles, and this Special Service Tool from Toyota is the authentic way to get the job done. The shims control the alignment of your knuckle with your axle housing. If not shimmed properlly, then your birfields, inner axle seals, spindle bushings and locking hubs will be out of alignment and will experience excessive wear and may even bind.