inflation pressure JEEP CJ 1953 Service Manual

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

Q
ice, provide maximum safety over all
types
of

terrain,
and furnish the medium on which the
vehicle can be maneuvered with ease. Although
there are other
elements
of tire service, inflation maintenance is the most important and in many
instances the most neglected. The tire pressure should be maintained for safe operation. An under- inflated tire is dangerous as too much flexing can
cause breakage of the casing. Overinflation in time
may
cause a blowout.

Upon
careful inspection of tires, it may be found
that improper wheel alignment, balance, grabbing
brakes,
poor driving habits, fast cornering or other
conditions are the cause of wear. Such conditions
should be corrected.

a.
UNDERINFLATION

Underinflation
distorts the normal contour of the
tire
body and the tire
bulges
or "bellies out" with

an
extreme flexing action.
This
wears the tread at the
edges
more than the center and generates
excessive internal heat, weakening the cords and
resulting
in bruises, broken cords or ply separation.

Underinflation
also leads to rim bruises as in­ sufficient resistance is provided to prevent the tire

from
being jammed against the rim and crushed
or
cut when the tire strikes a
curb,
rock, or rut.

b.
OVERINFLATION

When
a tire is
overinf
lated,
increased tension caused by excessive pressure prevents proper deflection of
the sidewalls.
This
results in wear in the center of the tread and the tire also
loses
its ability to absorb

road
shocks. Under this increased
strain,
cords in the tread area eventually snap under impact, caus­ing a casing break.

c.
MISALIGNMENT
WEAR
Excessive
wheel camber causes the tires to run at an angle to the road when camber is incorrect

it
will
cause excessive wear on one side of the
tire
tread.

Front
wheels should be straight ahead or toe-in slightly. When there is excessive toe-in or
toe-out,

tires
will
revolve with a side motion and scrape
the tread rubber off.
Front
tires
will
show wear on the outside with too great a toe-in condition
and
on the inside with a
toe-out
condition.

d.
BALANCE
Cupping
and bald spotting of tires is associated

with
wear on a vehicle driven mostly at high-way
speeds
without the recommended tire rotation and

with
unbalance conditions.

Q-12.
Tire
Care
Note;
For satisfactory 4-wheel drive operation, a
4-wheel drive vehicle
MUST
be equipped with the same size tires of equal circumference on all
four wheels. The tires must then be inflated to

proper
factory recommended pressures at all times.

Tire
pressure, tire rotation, wheel balance, and wheel alignment are the four vital factors that in­
fluence the
extent
of tire life and the
ease
and safety of vehicle control.
Four
of the most common

tire
troubles are:

a.
Excessive wear around the outer
edges
resulting

from
underinflation.

b.
Excessive wear in the center of the tread re­
sulting from overinflation.

c.
Tire
tread worn on one side indicating wheels
need realigning.
d.
Cuplike
depressions on one side of the tread

indicating
wheels need balancing.

If
the vehicle normally carries a
full
load, two to
four psi. [0,14 a 0,28 kg-m2] can be added to the
recommended air pressures. But, remember that adding air with a light load means a harsher ride,

doesn't
help tires, and wears out shock absorbers. Rotate the tires as shown in Fig. Q-9 for correct
rotation system.

Q-13.
Tire
Removal
and
Installation

To
remove a tire from a drop center rim, first
WEAR
AT SHOULDERS

WEAR
AT CENTER

WEAR
ON ONE
SIDE
FEATHERED
EDGE
BALD
SPOTS

/1TTDN

i

UNDER
INFLATION
OVER
INFLATION
EXCESSIVE
CAMBER

INCORRECT
TOE
WHEEL
UNBALANCED

liF
11

ADJUST
PRESSURE TO
SPECIFICATIONS
WHEN
TIRES ARE
COOL
ADJUST
CAMBER
TO

SPECIFICATIONS
ADJUST
FOR

TOE-IN
DYNAMIC
OR
STATIC

BALANCE
WHEELS

FIG.
Q-8—TIRE
WEAR
PATTERN
339

Q

WHEELS

11463

FIG.
Q-9—TIRE
ROTATION
1—
Right
Front
Tire

2—
Right
Rear
Tire

3—
Spare
Tire
4—
-Left
Rear
Tire

5—
Left
Front
Tire
deflate completely and then force the tire away

from
the rim throughout the entire circumference
until
the bead falls into the center of the wheel

rim.
If the vehicle is equipped with tires that use

an
inner tube, carefully remove the inner tube.
With
the inner tube removed, or on tubeless tires, a tire
removing tool should be used to remove the tire

from
the rim.

Installation
of the tire is made in the same manner
by first dropping one side of the tire into the center
of the rim and with a tire tool raise the bead over
the wheel
rim.
The inner tube can now be installed
on vehicles so equipped.
When
mounting the wheel, alternately tighten op­
posite stud nuts. After the nuts have been tightened

with
the wheel jacked up, lower the
jack
so wheel rests on the floor and retighten nuts. Torque nuts
to 60-75 lb.-ft. [8,3 a 10,4 kg-m.].

Note:
New "wide" tires have been given new sizes
by tire manufacturers. They use a letter as a key
unit
in the name size for the new wide treads.

The
single letter in front of the "70" indicates load rating, or the weight a tire can support safely
when inflated to 32 psi. The number 70 is used to show the
7-to-10
(70 percent) ratio of tire section height to width. The last two-digit number of the new sizes— 15 —
is
the rim diameter.
Radial

ply
tire sizes all contain the letter
"R"
to designate
radial
ply construction.

15-inch
Diameter
New Old

E70-15
7.35-15

F70-15
.7.75-15

G70-15
8.15-15

H70-15
8.45-15
J70-15
.8.85-15

K70-15
. .... .9.00-15

L70-15
9.15-15

You
should explain to customers
these
new tire
designations. Such knowledge
will
act as a re­
minder
never to mix
radial
ply, wide treads or
conventional tires on one axle.
0-14.
WHEEL
AND
TIRE
SPECIFICATIONS
'Jeep'

Universal

V6
Engine

CJ-5,
CJ-6,
CJ-5A,
CJ-6A
'Jeep*

Universal

F4
Engine

CJ-3B,
CJ-5,
CJ-6
DJ-5,
DJ-6

WHEELS:
Rim
Size 15 x
6.00
16 x 4.50
15 x 5.50

K
E
K

Attachment

Type
Stud
Stud Stud

Circle
Dia 5.50 5.50 5.50

5 5
4

Size
H-20
H-20
H-20

Rear
Axle Shaft End Float .001*-.006"
.001"-.006" .001 *-.006"
[0 ,025 a 0,152 mm.)
[0,025 a 0,152 mm.] [0,025 a 0,152 mm.]

TIRES:
Size.
7.35-15

6.00-16
6.85-15

Ply
Rating 4
4 2
Revolutions per Mile @ 30 mph.. . 781 730 803

Inflation
Pressure

Front
20
psi
[1,406 kg-cm2]
20 psi [1,406 kg-cm2] 24 [1,687 kg-cm*]

Rear
24
psi
[1,687 kg-cm*]
20 psi [1,406 kg-cm2] 24 [1,687 kg-cm*] 340