Introduction to Heavy Duty Truck Wheel Alignment

Alignment Definition

Wheel alignment is defined as the process of lining up all wheels of a vehicle to a common reference. Proper wheel alignment saves fuel, insures proper handling and extends tire life.

Alignment Reference

The two common types of alignment references are axle-to-axle and axle-to-frame. Individual toe measurements may differ depending on which reference procedure is used. Axle-to-axle alignment procedures are far more common in practice.

Alignment Angles

The primary alignment angles for multi-axle heavy duty trucks are:

-Camber

-Caster

-Total Toe

-Individual Toe

-Thrust Angle

-Tandem Scrub Angle

Front Suspension

Front suspension can either be independent or non-independent. Non-independent suspension is characterized by the solid connection between the wheels a common axle. Non-independent suspensions are simpler and therefore require less maintenance. 

Independent suspensions are characterized by each wheel being mounted to the chassis separately. This designs benefits include improved tire life, ride quality, and directional stability.

Alignment Specifications

Heavy duty commercial trucks with non-independent front suspensions are aligned to specifications given by the manufacturer based on the front axle. The front axle can typically be identified in one of the following areas:

-Stamped on the front axle

-On a tag attached to the front axle

-On the trucks line sheet

-In the trucks VIN