
WHEELS AND TIRES 10-3
Fig.
3 - Spof Wear
to cautioning the owner of his driving habits, is to inter-
change tires regularly.
Side
This may be caused by incorrect wheel camber, under-
inflation, high cambered roads or taking corners at too
high a rate of speed.
The first two causes are the most common. Camber
wear can be readily identified because it occurs only on
one side of the treads, whereas underinflation causes
wear on both sides (fig. 2).
There is, of course, no correction for high cambered
roads.
Cornering wear is discussed further on.
Center
This is caused primarily by overinflation pf the tire
(fig. 2). Invisible fabric damage can also be caused by
overinflation.
Uneven
Uneven or spotty wear (fig. 3) is due to such irregu-
larities as unequal caster or camber, bent front or rear
suspension parts, out-of-balance wheels, brake drums
Fig.
4 - Cornering Wear
out-of-round, brakes out-of-adjustment, or other me-
chanical conditions. The remedy in each case consists
of locating the mechanical defect and correcting it.
Cornering
Since the introduction of independent spring front and
rear wheels, improvements in spring suspension have
enabled drivers to negotiate curves at higher rates of
speed with the same feeling of security that they had
with the older cars at lower speeds. Consequently,
curves are being taken at higher speeds with the result
that a type of tire wear called "Cornering Wear" (fig. 4),
frequently appears.
When a car makes an extremely fast turn, the weight
is shifted from a normal loading on all four wheels to an
abnormal load on the tires on the outside of the curve
and a very light load on the inside tires due to centrifugal
force. This unequal loading may have two unfavorable
results.
First, the rear tire on the inside of the curve may be
relieved of so much load that it is no longer geared to
CHEVROLET CHASSIS SERVICE MANUAL

WHEELS AND TIRES 10-4
the road and it slips, grinding off the tread on the inside
half of the tire at an excessive rate. This type of tire
shows much the same appearance of tread wear as tire
wear caused by negative camber.
Second, the transfer of weight may also over-load the
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 ex-
cessive 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 in-
struction of owners.
Fig.
5 - Tire Rotatidh
Rotation
To minimize the possibility of tire noise and to equal-
ize tire wear, it is recommended that tires be inter-
changed every 6000 miles as shown in Figure 5 or more
frequently in the case of extremely heavy wear.
NOTE:
Rotate Corvette tires at 4000 miles or
sooner.
Interchanging tires will effectively prevent undue wear
on any particular tire. II tire interchanging is followed
as recommended above, all tires will have the same
number of miles in each wheel position at the end of the
fourth change. When interchanging tires, inspect for
signs of abnormal wear, bulging, etc., stones, glass, and
nails should be removed before reinstallation.
Noise
Noise caused by the normal action of tire treads on
various road surfaces is often confused with rear axle
gears or other noises in the car.
The determination of whether tires are causing the
noise complained of is relatively simple. The car should
be driven at various speeds and note taken of part
throttle, and sudden acceleration and deceleration. Axle
and exhaust noises show definite variations under these
conditions, while tire noise will remain constant. Tire
noise is, however, most pronounced at speeds of approx-
imately twenty or thirty miles per hour.
The tires may be further checked by driving the ear
over smooth pavement with the tires at normal pressure
and again over the same stretch of pavement when the
tires have been inflated to fifty pounds pressure. Reduce
the tires to normal pressure one at a time to determine
the faulty tire or tires. This high inflation pressure
should immediately be reduced to normal after test. If
the noise for which the test is being made is caused by
tires,.
it will noticeably decrease when the tire pressure
is increased, whereas axle noise should show no change
in volume.
If, on inspection, the tires on the front wheels are
found to be creating most of the noise the alignment of
the front wheels should be checked. Excessive tire noise
usually results from lower than recommended tire pres-
sure, incorrect alignment, uneven tire wear, or defective
(thumper) tire.
Cleaning
A great deal of ordinary road dirt which collects on
white sidewall tires may be sponged off with clear water
or a mild soap solution.
A good brand of whitewall tire cleaner, however, is
a quicker and more effective cleaner for removing dirt
and stains from whitewall tires and in many cases it
will remove stains and discoloration that the simpler
method of soap and water will not remove.
Under no circumstances should gasoline, kerosene or
any cleaning fluid containing a solvent derived from oil
be used to clean whitewall tires. Oil in any form is
detrimental to tire rubber and a cleaner with an oil base
will discolor or injure whitewall tires.
Change (W/Wheels)
To change the road wheels using the jack that comes
with the car, observe the following procedure:
1.
Set hand brake and block front wheels if rear wheel
is being changed.
2.
Remove hub cap or wheel disc and break wheel
mounting nuts loose.
3.
Place the jack as directed tinder, General Informa-
tion,
Section 0 and raise car until wheel clears
ground.
4.
Remove wheel mounting nuts and remove wheel from
hub or drum.
5. To replace road wheel, reverse the above instrue-
. tions. Proper torque on nuts is 55-75 ft. lbs.
torque (70-85 ft. lbs. for Corvette aluminum wheel
nuts).
CAUTION: On models equipped with discs, in-
dex the pilot hole in the disc on the valve stem.
(To insure that the anti-rotation notches in wheel
disc register on lugs in wheel rim.)
CHEVROLET CHASSIS SERVICE MANUAL

WHEELS AND TIRES 10-5
WHEELS
The wheel and tire assembly should be removed from
vehicles equipped with disc brakes to properly perform
balancing operations. This is necessary due to drag of
the spring loaded brake shoes on the disc.
Static Balancing (W/Tire)
Static Balance (still balance) is the equal distribution
of weight of the wheel and tire assembly about the axis
of rotation so that the assembly has no tendency to rotate
by
itself.
Static unbalance causes the pounding action of
the front wheels that is called "tramp".
To correct static unbalance (front and rear): The
quickest and best methods to correct static unbalance
are through the use of wheel balancers which are com-
mercially available. Refer to the Information and in-
structions included with these balaricers.
Dynamic Balancing (W/Tire)
Dynamic Balance (running balance) requires the wheel
to be not only in static balance, but balanced and running
smoothly while turning on an axis which runs through the
centerline of the wheel and tire perpendicular to the axis
of rotation.
The quickest and best methods of testing and correcting
dynamic unbalance are by the use of dynamic wheel
balancers which are commercially available. These bal-
ancers include all necessary information on where and
how the balancing weights should be placed. The follow-
ing information, however, will help in the correction of
dynamic balance.
NOTE:
Before attempting to balance the
wheels, check to be certain that no foreign
matter has been trapped in the wheel ventila-
tion slots or in the accessory wheel discs. This
is especially important if the vehicle has been
run in soft mud and then parked in freezing
weather.
When a wheel that is statically unbalanced is dynam-
ically in balance the dynamic balance can be retained
while correcting "the static balance by installing the cor-
rective weights so that half of the weight required is
placed on the inner edge of the rim and the other half
on the outer edge of the rim.
Dynamic unbalance can be corrected without destroying
static balance by installing weights so half of weight
required for dynamic balance is placed on the rim op-
posite the heavy point, while the other half is placed 180°
away and on the opposite side of the rim.
NOTE:
Vehicles with wire wheel covers should
have the wheels balanced with the wire wheel
covers installed on the wheels.
Run Out (W/OTire)
The wheels should not run out (wobble) more than
1/16" as measured on the side of the rim at the base
of the tire. Excessive run-out is the result of a bent
wheel, an improperly mounted wheel, worn knuckle bear-
ings or steering connections. These parts should be
checked for correct adjustment, proper alignment and
wear whenever excessive run-out is encountered.
The wheels should also run concentric with the steering
knuckle spindle within 1/16 inch as measured on the tire
bead seat of the rim with the tire removed.
Wheel run-out, eccentricity and balance are closely
associated with steering and front wheel alignment.
Further information on these subjects will be found under
"Suspension".
Cleaning Aluminum Wheels
Do not use wire brush or abrasive cleaners when
cleaning wheels. Use only cleaners that will not react
with aluminum.
SERVICE OPERATIONS
TIRES
Removal
Dismounting tubeless tires presents no problems if the
correct procedures are used and the following precau-
tions observed.
1.
Remove the valve cap and valve core. Let out all the
air.
2.
Press the inner side of the tire into the rim well.
Use bead loosening tool or if regular tire irons are
used, take particular care not to injure or tear the
sealing ribs on the bead.
CAUTION: Never use tire irons with sharp
edges or corners.
3.
Using tire irons on the opposite side, remove bead,
taking small "bites" around the rim.
4.
Turn the tire over, and use two tire irons, one be-
tween the rim flange and the bead to pry the rim
upward, the other iron to pry outward between the
bead seat and the bead.
Installation
Extreme care must be exercised to prevent injury to
the sealing bead and circumferential bead when forcing
tire over rim.
1.
Apply a light film of Ruglyde or other suitable rubber
lubricant to sealing bead of tire.
NOTE:
The use of excessive lubrication may
lead to rim slippage and subsequent breaking of
air seal.
2.
Carefully mount the outer bead in usual manner by
using tire irons, taking small "bites" around rim,
being careful not to injure the tire bead.
CAUTION: DO NOT use a hammer, as damage
to the bead will result.
3.
Install the inner bead in the same manner.
NOTE:
If a seal cannot be effected in the fore-
going manner with the rush of air it can be
, accomplished by applying to the circumference
of the tire a tire mounting band or heavy sash
cord and tightening with the use of a tire iron.
On tire mounting machines, bouncing the tire
assembly is not required. The tire should be
CHEVROLET CHASSIS SERVICE MANUAL

WHEELS AND TIRES
10-6
lifted on the rim to force the top tire bead
against the top rim flange. The weight of the
tire will seat the bottom bead.
Repair
When a tire loses all or most of its air pressure,
particularly when driving at high legal speeds on today1 s
super-highways, recommended procedure is to remove it
from the wheel for complete inspection to be sure no
tire damage has occurred. Punctured tires should be
removed from the wheel and permanently repaired from
the inside.
Externally applied plug type repairs should be con-?
sidered temporary and the tire should be permanently
repaired as soon as possible.
Hot Patch Method
It is essential to thoroughly clean and remove all
foreign matter from the hole left by the puncturing-object
without enlarging the injury and then follow the manu-
facturer's instructions for vulcanizing the patch.
Rubber Plug Methods
There are several types of rubber plugs--some are
inserted from the inside of the tire; others are inserted
from the outside of the tire without demounting the tire
from the rim.
When using the plug method be sure to clean and
lubricate the hole with repair cement before inserting
the plug. Your tire supplier has available complete kits
containing materials, tools and detailed instructions for
making repairs with plugs. Follow instructions in the kit
you use.
Cold Patch Method
(Self Vulcanizing Type)
In this method it is essential to thoroughly clean and
remove all foreign matter from the hole left by the
puncturing object without enlarging the injury; also on
the inside of the tire, buff an area large enough for the
patch. Follow the manufacturer1 s instructions for appli-
cation of the special cement and self-vulcanizing cold
patch.
Pressure Gun Method
Several types of pressure guns are available. Consult
your tire supplier for materials and instructions.
Tire Installation Safety Precautions
When tires are mounted on dirty or corroded rims, or
when they are not properly centered on rims, the tire
bead may "bind" on the rim, and refuse to seat. Allowing
pressure to continue to build up within the assembly in
an attempt to seat the tire bead is a DANGEROUS PRAC-
TICE which can result in a broken tire bead, and serious
injury to the serviceman.
1.
Make sure that rim flanges and bead ledge (espe-
cially hump and radius) areas are smooth and clean.
Remove any oxidized rubber, dried soap solution,
rust, heavy paint, etc. with a wire brush, or, in ex-
treme cases, a file.
2.
Lubricate tire beads, rim flanges, and bead ledge
areas with a liberal amount of thin vegetable oil
soap solution, or approved rubber lubricant,
3.
Insure that air pressure build-up during the bead
seating process is not allowed to exceed 40 pounds
pressure. If beads have not seated by the time pres-
sure reaches 40 pounds, assembly should be deflated,
re-positioned on rim, re-lubricated and re-inflated.
4.
Make sure valve core is inserted in valve stem
prior to inflating.
5.
Use an extension gauge with clip on chuck so air
pressure build-up can be closely watched and so
that you can stand well back from the assembly
during the bead seating process.
WHEELS
Valve Assembly
Replace
NOTE: Always use new valve assembly when
replacing.
1.
Cut or drive old valve assembly out of rim.
2.
Clean valve hole and surrounding area on inside of
flange with steel wool.
Fig. 6 - Installing Valve
Fig. 7 - Rim Inspection
CHEVROLET CHASSIS SERVICE MANUAL

WHEELS AND TIRES 10-7
3.
Coat O.D. of new valve assembly liberally with the 2. Clean rim flange thoroughly with small piece of
mounting compound. steel wool or sand paper.
4.
Insert assembly through rim from inside (fig. 7). 3. Inspect the butt-weld in the rim flange area to make
Snap into place, using a pair of slip-joint pliers certain there is no groove or high spot (fig. 8).
with one jaw on rim and one jaw on base of valve 4. If air loss occurs at valve it can be corrected by
assembly. replacing valve core or valve assembly.
Rim
Repair
1.
Straighten the rim if it is bent or dented.
CHEVROLET CHASSIS SERVICE MANUAL

ELECTRICAL-BODY AND CHASSIS 12-3
Fig.
2 - T-3 Safety Aimer
wearing away the insulation due to vibration.
By referring to the wiring diagrams, circuits may be
tested for continuous circuit or shorts with a conventional
test lamp or low reading volt meter.
HEADLAMP ADJUSTMENT-
T-3 HEADLAMPS
CAUTION: Check and tighten radiator support
grille retaining bolts prior to attempting head-
lamp aiming. Distorted grille or supports in
this area will hinder proper aiming of head-
lamps. On Corvette models make sure head-
lamp panel is adjusted properly - refer to
"Headlamp Panel Travel Adjustment".
When aiming headlamps, vehicle should be filled to ca-
pacity with gas, oil, and water but no load. Tires should
be uniformly inflated to recommended pressure.
the T-3 Safety Aimer-Type B (fig. 2), is used for the
headlamp aiming description that follows. An adapter is
required with the Type B T-3 Aimer when adjusting the 7
inch headlamp used on the Chevy n vehicle.
1.
Drive vehicle onto selected aiming area. Bounce
vehicle several times and allow to settle.
2.
Remove headlamp bezels.
3.
Mount the T-3 Aimers on either the No. 1 or No. 2
pair of headlamps so that "the points of the headlamps
engage the smooth inner ring of the aimers.
HORIZONTAL
AIMING
SCREW
STRING OVER
"2R" ON AIMER ARM
Fig.
4—-Headlamp Horizontal Adjustment
NOTE:
In the dual headlamp installation, the
inboard unit is designated No. 1 and the outboard
unit is designated No. 2.
4.
Secure the aimers to the headlamp units by firmly
pressing knob at center of each aimer (fig. 3). Ro-
tate crossarms inboard to approximate horizontal
position.
NOTE:
Moisten suction cups slightly to obtain
maximum holding force.
5. With both aimers in place, knot both ends of elastic
string and, using slots provided, fasten string across
horizontal crossarms of each aimer.
6. Rotate both aimers so that the string just clears the
points on the crossarms.
HORIZONTAL ADJUSTMENT
7. a. Turn horizontal aiming screw, Figure 4, on left-
VERTICAL ADJUSTMENT SCREW
Fig.
3 - Installing Aimer on Headlamp Unit
Fig.
5 - Headlamp Vertical Adjustment
CHEVROLET CHASSIS SERVICE MANUAL

ELECTRICAL-BODY AND CHASSIS 12-4
b.
hand lamp until the string is positioned over the
crossarm centerline. Turn the screw clockwise
in making the final adjustment to take up play in
the headlamp mechanism.
Repeat the above procedure on the right-hand
lamp to complete the horizontal adjustment of the
headlamps.
VERTICAL ADJUSTMENT
8. a. Numeral "2" (fig. 5) should appear in the "down"
window of each aimer. If not, loosen knob at
underside of aimer arm and slide back and forth
until the numeral does appear.
NOTE:
This setting will give a 2" drop of the
headlamp high beam spot centerline on a screen
placed 25 feet forward of the vehicle. Check
state laws for proper vertical setting.
b.
Turn headlamp vertical aim screw (fig. 5) on left-
hand unit counter-clockwise until the bubble is at
the inner end of the glass tube. Then turn screw
clockwise until bubble is centered in tube.
c. Repeat this procedure on right-hand headlamp
unit to complete vertical adjustment of lamps.
9. Recheck the string at the ends of each crossarm for
correct setting and the bubble on each aimer for
centered position.
10.
Remove the aimers by pulling on the suction cup tabs
through the openings in the aimers (fig. 6).
11.
With headlamps properly aimed, replace headlamp
bezels.
HOW TO SELECT A LEVEL AIMING AREA
1.
Select area you believe to be level.
2.
Remove headlamp bezels and install Aimers on each
headlamp (fig. 3) making sure aiming lugs engage
smoooth inner ring of the Aimer.
"
To install Aimer,
press firmly on the knob extending out from the cen-
ter of the Aimer base. This forces the suction cup
into place on the Sealed Beam unit.:
3.
Loosen the slider knob beneath the aimer arm and
set the numeral "2" in the DOWN view window (fig.
7).
Back vertical lamp adjustment out on each lamp
until bubble is outside of black line of vial, then cen-
ter bubble in between black line of vial by turning
clockwise.
VERTICAL AIMING SCREW
VIEW WINDOWS
BUBBLE
Fig.
6 - Removing Aimer from Headlamp
Fog.
7- Selecting Level Aiming Area
4.
After botli bubbles are centered, turn the car around
end for end, making sure the tires are in the spots
made on the floor before the car was moved.
.5.
If the bubbles are still within the two outside black
marks on the vials, the floor is level enough to use
the Aimer as it comes from the factory.
NOTE:
A quick level check can be made by
using the T-3 Safety-Aimer as a level. Use
with a true eight to ten foot two by four as an
extension. Make sure pads on base of Aimer
are used. Place the board where you expect the
wheels to be and take readings as outlined above.
6. If either bubble moves outside the black lines of the
vial there is too much slant to the floor. Try driving
the car in at different angles onto the aiming area.
If bubbles can
not
be centered follow procedure under
"How to Compensate for Unlevel Floor."
NOTE:
When level portion of floor is obtained,
mark tire spots on floor so spots can be used
next time without calibrating Aimer.
TO COMPENSATE FOR UNLEVEL FLOORS
If your floor is not level within the limits specified, the
T-3 Aimer can be calibrated to compensate for the error
in the floor. Follow this procedure with both aimers.
1.
Drive the car onto the area for which you wish to
compensate the aimers, and install the aimers in
place on the headlamps.
2.
Loosen knob beneath the aimer arm and move the
slider until the bubble is centered.
3.
Record the numeral in the view window. (This nu-
meral is to be used only for recalibration.)
4.
Move the slider to a position halfway between this
recorded numeral and the numeral "2" in the
DOWN
window. (This numeral is used only in recalibration
and not for headlamp aiming.)
5.
Recalibrate aimers by turning screw shown in Figure
8 until the bubble is centered.
6. The T-3 Aimers are now calibrated for the selected
area. All future aiming must be done in the same
area and with the car pointed in the same direction.
Mark the tire spots on the floor so that other vehi-
cles can be located in the same position.
CHEVROLET CHASSIS SERVICE MANUAL

SPECIFICATIONS
21
WHEELS AND TIRES
SECTION 10
CHEVY II
Tire Usage and Recommended Tire Inflation Pressures
Pounds per Square Inch (PSI) Cool
Models
All Models Except
Station Wagon
Station Wagon
Tire
Ply
4 Ply Rating
2 Ply
8 Ply Rating
4 Ply
Tire
Usage
6.95 x 14
6.95 x 14
Standard Inflation Pressure
for all Loads
including Full Rated
1 to 6 passengers
+ 200
lbs. luggage
(1,100 lbs. load)
Front
26**
Rear
26**
1 to 6 passengers
+ 300 lbs. cargo
(1,200 lbs. load)
Front
24
Rear
40
Optional Inflation
Pressure for
Reduced Load
1 to 5 passengers
(750 lbs. load)
Front
24
Rear
24
1 to 5 passengers
(750 lbs. load)
Front
22
Rear
28
•Optional tires are not available.
**Add 2 psi when vehicle is equipped with V-8 engine.
1.
Tire inflation pressures may increase as much as
six (6) pounds per square inch (PSI) when hot.
2.
For continuous high speed operation (over 75
increase tire inflation pressures four (4) pounds per
square inch over the recommended pressures up to
a maximum of 32 pounds per square inch cool for
4-ply rating tires dr 40 pounds per square inch for
8-ply
rating tires. Sustained speeds above 75 MPH
are not recommended when the 4 pounds per square
inch adjustment would require pressures greater
' than the TpaxiTP^Tns stated above.
3.
Cool tire inflation pressure: after vehicle has been
inoperative for three (3) hours or more, or driven
less than one (1) mile.
Hot tire inflation pressure: after vehicle has been
driven ten (10) miles or more at 60-70 MPH.
4.
Station Wagon loads should be distributed as far
forward as possible.
5. Vehicles with luggage racks do not have a load limit
greater than the l,100# load (l,200# load for station
wagons) specified above.
6. When towing trailers, the allowable passenger and
cargo load must be reduced by an amount equal to
the trailer tongue load on the trailer hitch.
CHEVELLE
Tire Usage
Engine and Body Styles
L-6, All styles except Station Wagon
283 V-8, All styles except Station
Wagon, Spt. Sedan and Convertible
283 V-8, Sport Sedan and Convertible
327 V-8 Std., except Sport Sedan
and Convertible
327 V-8 Std., Sport Sedan and
Convertible
327 V-8 H.P., All styles
396 V-8, Pick-Up Delivery
396 V-8, Super Sport Convertible and
2-Door Coupe
All engines, Station Wagon
Standard 14 Inch
With A/C*
7.35
7.75
7.75
7.75
F70
7.75
Without A/C*
7.35
7.35
7.75
7.75
F70
7.75
Optional 14 Inch
With A/C*
7.75
—
-
--
-
7.75
(8-Ply Rating,
4-Ply)
Without A/C*
7.75
7.75
-
—
-
7.75
(8-Ply Rating,
4-Ply)
*A/C (Air Conditioning)
All tires listed are 4-ply rating, 2-ply unless otherwise specified.
CHEVROLET CHASSIS SERVICE MANW