Chevrolet 30 Series 1967 Service Manual page 478

WHEELS AND TIRES 10-4
Truck Wheel Balance Weights
All 1967 truck wheels equipped with a tubular side ring
(rolled flange rim) on the outboard side of the wheel rims
require special design weights to fit.
can be accomplished through use of these special balance
weights which are designed only for installations on the
outboard side of these wheels. Conventional weights fit
only the inboard side of these wheels.
Static Balance
Static balance (sometimes called still balance) is the
equal distribution of weight of the wheel and tire assem­
bly about the axis of rotation in such a manner that the
assembly has no tendency to rotate by itself, regardless
of its position. For example: A wheel with a chunk of
dirt on the rim will always rotate by itself until the heavy
side is at the bottom. Any wheel with a heavy side like
this is statically out of balance. Static unbalance of a
wheel causes a hopping or pounding action (up and down)
which frequently leads to wheel "flutter" and quite often
to wheel "tramp".
Dynamic Balance
Dynamic balance (sometimes called running balance)
means that the wheel must be in static balance, and also
run smoothly at all speeds.
To insure successful, accurate balancing, the following
precautions must be observed:
• Wheel and tire must be clean and free from all foreign
matter.
• The tires should be in good condition and properly
mounted with the balance mark on the tire, if any, lined
up with the valve.
• Bent wheels that have runout over 1/16" on 1/2,
3/4 and 1 ton, or 1/8" on 1 1/2 and 2 ton trucks
should either be replaced or straightened before being
balanced.
• Inspect tire and wheel assembly to determine if an
eccentric or out-of-round condition exists.
this condition, if severe, cannot be "balanced out". An
assembly which has an out-of-round condition exceed­
ing 3/16" on tire sizes through 19.5" and 5/16" on
sizes larger than 19.5", is not suitable for use on the
front of the vehicle. Its use on the rear should be
governed by its general condition and whether the
roundness defect seriously detracts from overall ride
quality.
• When balancing wheels and tires, it is recommended
that the instructions covering the operation of the wheel
balancer being used be closely followed.
WHEELS
Cast Spoke Wheels
Cast spoke wheels with demountable rims are available
on 50 and 60 series only. Rim and tire may be removed
from the wheel after removing nuts and clamps.
tires may then be
"Maintenance".
Dynamic balancing
Note that
The
serviced as outlined under
CAUTION:
When removing wheel, loosen all
nuts approximately flush with end of stud, then
tap clamps to loosen wheel. Do not remove nuts
until clamps are free as clamp may fly off stud.
Installation of Rims on Wheels
D u a l W h e e l s
.
Before positioning inner rim, thoroughly clean all
1
contact surfaces on both rim and wheel.
.
After inner rim is positioned, install separator ring
2
as shown in Figure 3.
3. Install outer rim and proceed as outlined under "Dual
and Single Wheels".
Fig. 3 - Installation of Spacer Ring
D u a l a n d S i n g l e W h e e l s
When installing the tire and rim on the wheel, the fol­
lowing procedure should be followed:
After rim clamps and nuts are put on loosely, turn the
wheel until one spoke is pointing straight upward; tighten
the nut on the spoke just snug. Snug up the remaining
nuts criss-cro ss to minimize runout, then tighten the nuts
to the recommended torque alternately and evenly to
avoid excessive runout.
Runout should not exceed 1/8" on front wheel of 3/16"
on rear wheel.
Matching Side and Lock Rings
Side and lock rings of different rim types are not inter­
changeable. Some may appear to be, but they do not fit
properly on the rim base. Serious accidents have re­
sulted from the use of mismatched rings. Rim base and
rings must be matched according to manufacturer, size
and type. This information is stamped on each part.
TIRE REMOVAL AND INSTALLATION
Tire Mounting
Safety Precautions!
When tires are mounted on dirty or corroded rim s, or
when they are not properly centered on rim s, the tire
CHEVROLET TRUCK SERVICE MANUAL