So you’ve installed lowering springs or raised your vehicle. It looks great, but your wheels are slanted and tires are wearing. Sounds like you need a camber kit! Camber is measured in degrees, both positive and negative. Camber can be the result of a bad alignment, wearing parts and changing the ride height on your vehicle; rather raising or lowering it. Camber takes valuable rubber off the road by ridding on the edges of the tires instead of the traction patch. With proper camber adjustment and alignment correction, the car will be more responsive, handle better wet and dry and your tires will last the manufacturers lifetime rating.

Negative Camber

When the top of the tire is more towards the center of the vehicle and the bottom is outwards, that is measured in negative camber. Negative camber wears the inside of your tires at a rapid rate. Lowering a vehicle brings the entire chassis closer to the tires. Everything is moving downwards except the tires. Obviously they cannot go down any more because they are on the ground. Since suspension is put together with the factory ride height in mind, parts are made to be installed and have near 0 degree camber. By lowering the suspension components but not the wheel, the wheel in essence lowers itself by tilting inwards. A camber kit corrects this problem by extending the length of the upper control arm, allowing the ball joint which holds the control arm in place to be adjusted. It can be moved out for negative camber correction or in for positive correction. This along with an alignment correction is the ultimate defense against camber wear.

Positive Camber

When the bottom of the tire is more inwards and the top is out, that is referred to as positive camber. Positive camber wears the outside of the tires at a rapid rate. Positive camber is generally the result of a bad alignment or wearing ball joint. A camber kit is not usually required for this because replacing the faulty part and realignment generally pulls everything into spec. One time a camber kit will be needed for positive camber is when the vehicles ride height is raised. When it is raised, it puts stress on the top ball joint because the wheels lifting motion conflicts with the ball joint position therefore pushing it to the side. With an adjustable camber kit, this is corrected by sliding the ball joint back inwards, towards the motor, to bring the wheel back into spec.

Positive caster improves straight line tracking because the caster line (the line drawn through the steering pivot when viewed from the side) intersects the ground ahead of the contact patch of the tire. Just like a shopping cart caster, the wheel is forced behind the pivot allowing the vehicle to track in a straight line.

If this is the case, then why did most cars have negative caster specs prior to 1975 ? There are a couple of reasons for this. In those days, people were looking for cars that steered as light as a feather, and cars back then were not equipped with radial tires. Non-radial tires had a tendency to distort at highway speed so that the contact patch moved back past the centerline of the tire (Picture a cartoon car speeding along, the tires are generally drawn as egg-shaped). The contact patch generally moves behind the caster line causing, in effect, a positive caster. This is why, when you put radial tires on this type of car, the car wanders from side to side and no longer tracks straight. To correct this condition, re-adjust the caster to positive and the car should steer like a new car.