Dodge R1500 1999 Service Manual page 1587

Fig. 3: Determining Camber Angle
CASTER
1) Caster is tilting of front steering axis either forward or
backward from vertical, as viewed from side of vehicle. See Fig. 4.
2) When axis is tilted backward from vertical, caster is
positive. This creates a trailing action on front wheels. When axis is
tilted forward, caster is negative, causing a leading action on front
wheels.
Fig. 4: Determining Caster Angle
TOE-IN ADJUSTMENT
Toe-in is the width measured at the rear of the tires