Chevrolet Light Duty Truck 1973 Service Manual page 183

COMPRESSION
SIDE
REBOUND
SIDE
PISTON ASSEMBLY
FRONT SUSPENSION
GEOMETRY (FIG. 15)
The term "front suspension geometry" refers to the
angular relationships between the front wheels, the front
suspension attaching parts and the ground. The angle of
the knuckle (or steering axis inclination) away from the
veritcal, the pointing in or "toe-in" of the front wheels,
the tilt of the front wheels from vertical (when viewed
from the front of the vehicle) and the tilt of the
suspension members from vertical (when viewed from
the side of the vehicle), - all these are involved in front
suspension geometry. The various factors that enter into
front-end geometry are covered here each one under its
own heading.
CASTER
Caster is the tilting of the front steering axis either
BACK WASHER
INTAKE SPRING
INTAKE VALVE DISC
PISTON-HIGH SPEED ORIFICE
TYPICAL REBOUND ORIFICE DISC
REBOUND SPRING DISC
SPACING SPRING DISC
SPRING SEAT
REBOUND SPRING
PISTON NUT " ► i
Fig. 13—Piston Valving Parts
Fig. 14—High Speed Orifices in Piston
WHEEL ALIG NM EN T
forward or backward from the vertical (when reviewed
from the side of the vehicle). A backward tilt is said to
be positive(-F) and a forward tilt is said to be negative
(—). On the short and long arm type suspension you
cannot see a caster angle without a special instrument,
but you can understand that if you look straight down
from the top of the upper control arm to the ground you
would find that the ball joints do not line up (fore and
aft) when a caster angle other than 0° is present. If you
had a positive caster angle the lower ball joint would be
slightly ahead (toward the front of the vehicle) of the
upper ball joint center line. In short then: caster is the
forward or backward tilt of the steering axis as viewed
from a side elevation. Caster is designed into the front
axle assembly on all K series vehicles and is non-
adjustable. See caster copy under ADJUSTMENTS.
FRONT SU S PEN SIO N
LO W SPEED
ORIFICE
— BLOW-OFF
VALVE
LIGHT DUTY TRUCK SERVICE MANUAL
3-9