Ch. 30 Alignments

Primary Angles

100

This angle is the side‑to‑side vertical tilt of the wheel.

camber

200

This angle is the forward or backward tilt of the steering axis when viewed from the side.

caster

300

When the fronts of the wheels are closer together than the rears, this condition exists.

Toe-in

400

This angle is the most responsible for rapid tire wear if incorrect.

Toe 

500

These three angles make up the primary alignment angles.

Camber, Caster, Toe

Secondary Angles

100

This angle is formed between the SAI and the camber line.

Included Angle

200

This angle describes the direction the rear wheels are pointed.

Thrust Angle

300

This diagnostic measurement shows how far one wheel sits forward or backward on the same axle.

Setback

400

This angle determines how sharply the inner wheel turns during cornering.

Toe‑out on Turns

500

This vertical measurement must be checked before alignment and is measured at factory‑specified points.

Ride Height

Alignment Types

100

This alignment type adjusts only the front wheels.

Front‑end (Two‑wheel) Alignment

200

This alignment measures all four wheels but usually adjusts the front only.

Thrust‑angle Alignment

300

This alignment adjusts all four wheels.

Four‑wheel Alignment

400

This type is most common today on vehicles with a solid rear axle.

Thrust‑angle Alignment

500

Modern alignment machines always measure this many wheels, even if only the front is adjusted.

All four wheels

Adjustment Methods

100

These small tapered pieces are added between components to adjust angles.

shims

200

These bolts have off‑center pivots to change camber or caster.

Eccentric Bolts

300

This sleeve type is used on some ball joints to change camber.

Ball Joint Adjusting Sleeve

400

Tie rod ends are used primarily to adjust this angle.

Toe

500

Alignment adjustments must be performed in this specific order, starting with the rear.

Rear: caster → camber → toe, then Front: caster → camber → toe

Alignment Pre‑Checks & Diagnostics

100

This must be done before an alignment to ensure the vehicle is level and within spec.

Check/Adjust Ride Height

200

This condition often results in “crab walking.”

Rear Thrust Angle Issue

300

This sensor often requires recalibration after an alignment.

Steering Angle Sensor

400

Bent steering arms will usually show up as an incorrect reading in this secondary angle.

Toe‑Out‑On‑Turns

500

Incorrect readings in this angle pair often indicate a bent knuckle or damaged suspension parts.

SAI and Included Angle