Chevrolet 70 1969 Series, Shop Manual

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REAR SUSPENSION 4B-22
SECTION 4B
REAR SPRINGS AND SUSPENSION
VARi-RATE REAR SPRINGS
Vari-rate type rear springs, shown in fig­
ure 1 are used on some conventional models with
single rear axles. The front spring eye is bronze
bushed and pinned to a bracket at front and is cam
supported at rear. C am action of the spring leaf
produces a variable deflection rate as contact
point changes under varying load.
Progressive type, two stage, rear spring,
shown in figures 2 and 3, have a straight ended
main leaf which rests against the cam surface of
the front and rear hangers, thereby allowing the
springs a full fore and aft float to effect spring
length changes.
The second or third leaf has
hooked ends which contact rebound pins in the
spring hanger to prevent excessive fore and aft
travel in event of radius leaf rod failure. The
radius leaf rods maintain axle alignment and
transmit driving and braking forces to the frame.
On tilt cab models, a spacer is used at bottom
of spring pile to separate the last leaf from the
radius leaf which is half-leaf formed with an eye
and bushed for attachment to the front and rear
hangers. Two slanted U-bolts attach the spring
pile and radius leaf to the axle housing.
On conventional cab models, the radius leaf
rods have an eye and bushing at each rod end.
N O T E : Refer to "Service Diagnosis Chart" in
" F R O N T SPRINGS" (SEC. 3C) of this manual.
REAR SPRING REPLACEMENT
R E A R SPRING R E M O V A L
1. Remove bolts and lock washers usedtohold
rebound pin locks or retainers to spring brackets.
Pins are installed flush with surface of bracket
with retainer hooked over side of bracket; or the
locks fit into a groove in the rebound pin. Refer to
figure 4 and remove rebound pins.
Figure 1 — Pinned Type Hear Suspension (Typical)
CHEVROLET SERIES 70-8CI H EAVY DUTY TRUCK SH O P M A N U A L