Chevrolet 10 1971 Series Chassis Service Manual page 370

WHEELS AND TIRES 10-2
t r e a d
STILL G O O D
Fig. 3 — Passenger Type Tire Tread W e ar Indicator
Tread Wear
When the depth of tread becomes 1/16-inch or less,
there is a significant decrease in traction and anti-skid
properties, also, the majority of tire troubles will occur
in the last 10% of tire life.
The original equipment passenger type tires on Series
10 trucks incorporate built in tread indicators to assist
in judging when tires are worn out and should be re­
placed.
These indicators are molded into the bottom of the
tread groove and will appear as bands across the tread
as a visual reminder that the tire should be replaced
(see fig. 3).
MAINTENANCE
WHEEL NUT TORQUES
On a new vehicle or after the wheel has been changed,
the wheel nut torque must be checked at 100, 1,000 and
6,000 miles and every 6,000 miles thereafter.
TIRE ROTATION
The rotation of truck tires will minimize tire trouble
and produce longer tire life. ;With rotation, accelerated
and irregular tire wear on any One particular tire will
be spread out over the entire set, and replacement fre­
quency will be reduced. Tire wear may also contribute
to such trouble as poor handling and shimmy.
No definite tire rotation formula is applicable to all
trucks because of the wide range of usage. However,
certain fundamentals, mixed with experience and obser­
vation, will assist the trucker in reducing tire costs.
A rotation sequence that moves the front tires to the
rear is a general recommendation. Due to different
loading conditions on the wheels, new tires which are
broken in on the front wheels usually produce the great­
est overall tire life.
The outer tire on a dual wheel will skid or drag on a
turn because of the difference in the turning radii of the
inner and outer tires. This results in faster wear of the
outer tire. In general, the tire with the largest diameter
or least wear should be at the outside of each dual wheel.
In addition, certain truckers have found when trucks are
operated continuously on high crown roads an increase
in air pressure of from 5 to 10 pounds in the outside tire
of each dual produces maximum tire life.
rotated every 6,000 miles. Upon rotation, tire pressure
t r e a d
must be adjusted (front and rear) in accordance with the
W O RN OUT
recommendations in the "Tire Load and Inflation Pres­
sure" table.
Inflation Pressure
"Load Capacity Chart" in the Section 0, "General Infor­
mation," in this manual. These are the minimum re­
quired tire pressures for maximum permissible loads.
tire life and load carrying capacity, and may affect ve­
hicle handling. Inflation pressures should be checked at
least once a month (and preferably more often) to insure
that the right amount of air is contained in the tires.
With regard to tire life, too little air pressure allows
abnormal deflection of the tire causing excessive operat­
ing temperatures, while too much air pressure prevents
normal deflection, making the cord body more vulnerable
to road impacts.
duced load.
duced load, the inflation pressure must be increased to
the standard inflation for full rated loads.
Inflation pressures shown below for passenger type tires are for normal ride
and handling use. Pressures may be required up to a maximum of 32 psi cold
for load range B tires or 36 psi cold for load range C tires for maximum load
carrying capacity.
*Cargo load reduced by 225# when the vehicle is equipped with hard top.
ALSO R E F E R TO " T I R E L O A D AND I N F L A T I O N P R E S S U R E
To equalize wear it is recommended that the tires be
Standard inflation pressures for tires are listed in the
The use of improper tire inflation pressures can affect
Use of optional inflations is allowable only with a re­
When operating at loads greater than the optional re­
TIRE LOAD AND INFLATION PRESSURE
Max. G ro ss
M O D E L
Vehicle Wgt.
[Incl. P a sse n g e r s)
P I C K U P S AND C A B S
4400
CS/CE10
5400
5200
K S / K E 107-109
5600
FORWARD C O N T R O L (S T E P VANS)
4600
PS/PE10
5300
5400
B L A Z E R M O D E L S
(F rt. Seat Only)
2 Passenger
-
*+ 4 5 0 # Cargo
(F rt. Seat Only)
-
2 Passenger
*+ 850# Cargo
S U B U R B A N S
C S /C E 1 to 3 Pass.
(1 Seat)
-
+ 3 0 0 lbs. Cargo
1 to 5 Pass. (2 Seat)
+ 6 0 0 lbs. Cargo
-
1 to 9 Pass. (3 Seat)
T A B L E N O T E S " 1 T HR OU G H 8.
In flation P re ssu re
T ire Size
P S I (C o ld )
& Load R a n g e
Front Rear
G78-15 B
30 32
6.50-16 C 30 34
H78-15 B 30 32
G78-15 B 30
32
6.50-16 C 30 34
H78-15 B 30
32
G78-15 B 30 32
6.50-16 C 30 34
H78-15 B 30 32
E78-15 B 30
32
G78-15 B 30 32
H78-15 B 30 32
30
6.50-16 C 32
G78-15 B
30 32
6.50-16 C
30 36
H78-15 B 30 32
10-30 CHEVROLET TRUCK SERVICE MANUAL