Chevrolet LIGHT DUTY TRUCK (SERIES 10-35) Service Manual page 341

3E-4 WHEELS AND TIRES
WHEEL USAGE AND TIRE LOAD LIMITS AT VARIOUS INFLATION PRESSURES*
W h e e l C o d e
R e g u la r R a lly
Z R . ZD
-
XX. X W
-
XX, X W
-
Z R. Z D
-
ZF
-
ZF
-
ZF
—
ZY. ZT
-
Wheel load lim its are shown on page 5-29.
, the transfer of weight may also overload the
Second
outside tires so much that they are laterally distorted
resulting in excessive wear on the outside half of the tire,
producing a type of wear like that caused by excessive
positive camber.
Cornering wear can be most easily distinguished from
abnormal camber wear by the rounding of the outside
shoulder or edge of the tire and by the roughening of the
tread surface which denotes abrasion.
Cornering wear often produces a fin or raised portion
along the inside edge of each row in the tread pattern. In
some cases this fin is almost as pronounced as a toe-in fin,
and in others, it tapers into a row of tread blocks to such
an extent that the tire has a definite "step wear" appearance.
The only remedy for cornering wear is proper
instruction of operators. Driving more slowly on curves and
turns will avoid grinding rubber off tires. To offset normal
cornering wear as much as possible tires should be
interchanged at regular intervals.
W h eel and Tire Balancing
It is desirable from the standpoints of tire wear and
vehicle ride and handling ease to maintain proper balance
of wheel and tire assemblies on all models. This may be
accomplished by either of the two types of balancing
systems in currect use which balance wheels either on the
vehicle or off. The "on the vehicle" type, however, is the
more desirable in that all rolling components (brake drums,
bearings, seals, etc.) are included in the balancing procedure
and thereby have any existing unbalance corrected.
LIG H T T R U C K SER V IC E MANUAL
T IR E S FOR LIG H T TR U C K S USED IN H IG H W A Y SER V IC E
T IR E S U S E D A S S IN G L E S
T ire Lo a d
30
Size R a n g e
T U B E T Y P E T IR E S M O U N T E D O N 5° T A P E R E D B E A D S E A T R IM S
6.50-16 C 1270
7.00-15 C 1350
7.00-15 D 1350
7.00-16 C 1430
7.50-16 C 1620
7.50-16 D
1620
7.50-16 E 1620
T U B E L E S S T IR E S M O U N T E D O N 15° T A P E R E D B E A D S E A T D R O P C E N T E R R IM S
8.19-5 D
-
V eh icle loading must be lim ited such that neither the wheel or tire load lim its are exceeded.
Fig. 3E -5--Tire/W heel Load and Infla tion Pressure 2 of 7
T ire L o a d Lim its at V a rio u s In fla tio n P re s s u re s
35 40 45 50
1390 1500 1610
1480 1610 1720
1480 1610 1720 1830
1560 1680 1800
1930 2060
1770
1770 1930 2060 2190
1770 1930 2060 2190
2110
- - -
T ru ck W h ee l Balance W e ig h ts
All 1979 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. Dynamic balancing 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.
S ta tic Balance
Static balance (sometimes called still balance) is the
equal distribution of weight of the wheel and tire assembly
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 chunk of dirt on
the rim will always rotate by itself until the heavy side is
a 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".
D ynam ic 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.
( P S I )
70
55 60 65
1940 2040
2310 2440
2560 2670
2310 2440
2680
2270 2410 2540
75
2780
2800