The camber angle is the inward or outward tilt of the top of the tire toward or away from the vehicle as viewed from the front of the vehicle. The more the top of the tire leans in toward the vehicle, the more negative the camber. The more the top of the tire leans away from the vehicle, the more positive the camber. An out of specification camber angle will cause a tire to wear on one side or the other. There are many ways to adjust camber depending on the vehicle make and model. Always make sure the caster and camber are correct before adjusting the toe.
Eccentric cam: Eccentric cams are used on short arm long arm and some MacPherson strut suspension systems. On MacPherson strut systems, a slotted hole is located on the strut arms bolt hole adjusting and attaching it to the steering knuckle. Usually the cam is slotted onto an eccentric bolt and as the bolt is turned, the strut arm is moved inward or outward for camber adjustments. These cams are sometimes found on the rear suspension of vehicles. Some vehicles have eccentric cams located on the upper control arm and others are located lower.
Shims: Shims are used to change camber on short arm long arm suspension systems. They’re added or subtracted to the upper or lower control arm mounting bolts. After the camber has been adjusted the caster and toe must be checked. Some vehicles use a slotted upper strut mount. For vehicles with non-adjustable camber, an aftermarket slotted strut tower is often available. On twin I-beam suspension systems the beam is bent or a sleeve is moved to adjust camber.