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
10-6
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
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 12-22
SERVICE OPERATIONS
INSTRUMENT CLUSTER
Removal and Installation (Figs. 36 thru 40)
I. Disconnect battery ground cable.
2:
Remove four screws retaining instrument bezel to
top edge of instrument console. Disengage tabs on
bezel lower section from clips on instrument console
and remove bezel.
3.
Protect mast jacket to prevent scratching when re-
moving cluster assembly.
4.
Remove eight screws securing leading edges of in-
strument cluster to console and pull cluster forward
from console opening.
5. Reaching behind cluster disconnect speedometer ca-
ble,
chassis harness connector, clock and speed
warning device connections (if so equipped) at rear of
cluster.
NOTE:
On models- with gauge pack, disconnect
oil pressure line also.
6. When all disconnects are made, remove cluster as-
sembly from vehicle.
7. To install, position cluster assembly to console
opening and connect speedometer cable, chassis
harness connector and other electrical connections
as required.
8. Position cluster in console opening and install eight
retaining screws.
NOTE:
Make sure ground strap between
cluster case and center right lower attachment
is properly installed.
9. Engage tabs on instrument bezel with clips on con-
sole and position bezel in console opening, then in-
stall four retaining screws.
10.
Install speed warning device control attaching nut and
knob,
if so equipped.
II.
Connect battery ground cable and check operation of
cluster assembly.
Fig. 36 - Instrument Cluster Installation — Chevrolet
Fig. 37 - Speed Warning Device
INSTRUMENT CLUSTER LAMP REPLACEMENT
(Figs.
38 and 39)
1.
Rotate socket counterclockwise to remove from rear
of cluster housing.
2.
To remove bulb, if socket is black color, pull bulb
straight out. If socket is gray color, depress and
rotate bulb, then pull out.
3.
Install replacement bulb in socket, pressing inward
to lock in place.
4.
Insert socket into housing, with lugs entering notches
in case, and rotate clockwise to lock in place.
PRINTED CIRCUIT REPLACEMENT (Figs. 38 and 39)
1.
Remove instrument cluster as previously described
in this section.
2.
Remove all cluster illuminating and indicator lights
from cluster housing.
3.
Remove fuel gauge and clock terminal nuts securing
printed circuit to housing.
4.
Remove four hex head screws retaining printed cir-
cuit to the cluster housing and remove the printed
circuit. . .
5. To install, reverse removal procedure.
CAUTION:. The retaining screws and terminal
nuts are part of the grounding circuit and must
be installed to provide the proper ground con-
nections for the printed circuit.
SPEEDOMETER
REPLACEMENT
1.
Remove instrument cluster as previously described
in this section.
2.
Remove screws retaining rear cover to the cluster
assembly. Bend ground strap away from cover and
remove cover.
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY AND CHASSIS 12-24
1.
Temperature Gauge
2.
Instrument Cluster Lamp
3.
R.H. Directional Indicator
4.
Ammeter Gauge
Fig. 39- Optional Gauge Cluster
5. Fuel Gauge
6. L.H. Directional Indicator
7. Tachometer
8. "Brake" Indicator
9. "Bright" Indicator
10.
Oil Pressure Fitting
11.
Chassis Harness Connector
12.
Clock Assembly
13.
Printed Circuit
NOTE:
Observe carefully the stack up of the
internal parts of the fuel gauge assembly.
5. To install, reverse removal procedure.
CLOCK OR TACHOMETER REPLACEMENT
NOTE:
The tachometer is a self-contained, all
transistor unit requiring very little service
other than keeping the terminal nuts clean and
tight. The unit is not serviceable and must be
replaced, if defective.
1.
Remove instrument cluster as previously described
in this section.
2.
For clock replacement, remove clock set shaft knob
at front of console.
3.
Remove cluster lamps from cover, circuit attaching
screws, and terminal nuts at circuit to gauge attach-
ing points.
4.
Move printed circuit away from gauge and remove
screws retaining
•_
gauge or clock to the cluster
housing.
•5.
Remove unit, from housing and cover plate from
gauge unit.
6/To install, reverse removal procedure.
AMMETER TEMPERATURE AND OIL PRESSURE
GAUGES REPLACEMENT
1.
Remove instrument cluster as previously described
iii this section.
2.
Remove instrument lamps, attaching screws or nuts
and wiring connections as required.
3.
Remove gauge assembly backing plate retaining
screws and remove gauge assembly from cluster
housing.
4.
Remove terminal nuts and/or screws retaining gauge
to the backing plate and separate plate from the
gauge.
•
5. To install, reverse removal procedure.
OIL PRESSURE INDICATOR
If the light does not come on when the ignition switch is
turned on, or if the light comes on and remains on after
the engine is started, one or more of the following condi-
tions is indicated:
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY
AND
CHASSIS
12-26
•
Low oil
pressure
• High engine temperature
• Defective wiring
or
switch
connector from sender
in block above starter
on
and
at
left front
of
distributor
on V-8
Sending Unit Replacement
1.
Disconnect wiring harness
unit terminal (located
L-6 engines
engines).
2.
Remove sender unit using Tool J-21757
or 12
point
socket, replace with
new
unit
and
check operation.
GENERATOR INDICATOR
1.
Ignition
on,
Engine
not
Running
and
Telltale Light
Off.
• Indicator bulb burned out, replace bulb.
• Open circuit
or
loose connection
in the
telltale
light circuit.
2.
telltale Light Stays
on
after Engine
is
Started.
If indicator light does
not go out at
engine idle
speed, refer
to
Charging Systems under Engine
Electrical, Section
6Y.
TEMPERATURE (COOLING SYSTEM) INDICATOR
The temperature indicator circuit consists
of two re-
motely located units, indicator gauge
and
engine sender
unit.
The
indicator gauge, located
in the
instrument
panel, consists
of a
red light which will indicate
an
over-
heated engine condition.
Engine Sender Unit Replacement
1.
Drain engine cooling system
to a
level below unit.
2.
Remove sender unit (located
in the
inlet manifold
near water pump housing
on V-8
engines and
in the
cylinder head near
an
exhaust port
oh L-6
engines)
and replace with new unit.
3.
Refill cooling system
and
check operation
of
unit.
CHEVELLE INSTRUMENTS AND GAUGES
INDEX
Page
General Description
* *
i2-26
Service Operations
12-26
Instrument Panel
12-26
Instrument Cluster.
12-26
Fuel Gauge and/or Ammeter
12-27
Clock,
i 12-27
Speedometer
12-27
Page
Speedometer Cable
.
. 12-27
Temperature Gauge
12-29
Oil Pressure Gauge
12-29
Indicator Lights.
. 12-29
Oil Pressure Indicator
12-29
Generator Indicator
. . 12-29
• Temperature Indicator
12-29
GENERAL DESCRIPTION
The Chevelle instrument cluster assembly consists
of:
a speedometer;
a
fuel gauge;
a
generator,
an
engine
tem-
perature and an
oil
pressure indicator lamp, and includes
a clock
on
deluxe models.
On
super sport models,
am-
meter, coolant temperature
and oil
pressure gauges
re-
place
the
appropriate indicator lights. Except
for the
speedometer,
all of the
indicator lamps, instruments
and
gauges
of
these clusters may
be
serviced without remov-
ing
the
instrument cluster assembly from
the
vehicle.
In addition
to the
instrument indicator lamps,
a
brake
warning lamp
is
included
in the
cluster
as
standard
equipment.
The
indicator
is
connected
to the
parking
brake
and
brake pressure differential switches
and
serves
a
dual function.
It
lights when the parking brake
is applied
and
also when
the
brake pedal
is
applied,
if a
malfunction should occur
in the
brake system
due to a
loss
of
hydraulic pressure. Servicing
of the
hydraulic
pressure differential switch
is
covered
in
Section
5 of
this manual.
Regular maintenance
is not
required on the instrument
cjLuster
or its
components other than maintaining dean
and tight electrical connections, replacing defective parts
and keeping
the
speedometer cable properly lubricated.
SERVICE OPERATIONS
INSTRUMENT PANEL ASSEMBLY
INSTRUMENT CLUSTER (Figs.
41
thru
44)
Removal
1.
Disconnect battery ground cable.
2.
Remove steering coupling bolt and disconnect steer-
ing shaft from coupling.
3.
Loosen mast jacket lower clamp.
4.
Remove
air
conditioning center distributor duct
(if
so equipped).
5. Remove radio rear support bracket screw.
6. Remove mast jacket upper support clamp and retain-
ing bolts from lower support (refer
to
Section
9,
Steering).
CAUTION: Cover mast jacket
and
parl
brake handle with
a
suitable material
to
prevc
scratching.
7.
Disconnect speedometer cable
at
rear
of
cluster
housing
and
speed warning control knob
at
panel
(if
so equipped).
8. Remove instrument panel retaining screws (nine
upper and five lower).
.
9. Working under the console remove four lower retain-
ing screws from instrument cluster housing.
10.
Pull instrument panel assembly from console and
lay
forward on mast jacket.
11.
Disconnect wiring harness, cluster lamps and wiring
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY AND CHASSIS 12-29
Fig.
43b - Speed Warning Device
TEMPERATURE AND/OR OIL PRESSURE
GAUGE
1.
Disconnect battery ground cable.
2.
Remove ash tray and ash tray retainer.
3.
Disconnect A/C hose from the distributor duct.
4.
Disconnect wiring connectors and lamp bulbs from
rear of gauge.
5. Disconnect oil pressure pipe fitting from rear of oil
pressure gauge.
6. Remove (3) screws retaining gauge assembly to
cluster cover and disengage unit from cover.
7. Remove (4) retaining nuts and remove gauge from
template.
8. To install, reverse removal procedure.
INDICATOR LIGHT REPLACEMENT
To replace any indicator or cluster bulb, unsnap the
proper socket from rear of instrument cluster, remove
and replace bulb, and reinsert unit into rear of cluster
housing.
OIL PRESSURE INDICATOR
If the light does not come on when the ignition switch is
turned on, or if the light comes on and remains on after
the engine is started, one or more the following condi-
tions is indicated:
• Low oil pressure
• Defective wiring or switch
• High engine temperature
Switch Replacement
1.
Disconnect wiring harness connector from sender
unit terminal (located in block above starter on L-6
engines and at left front of distributor on V-8
engines).
2.
Remove sender unit using Tool J-21757, replace with
new unit, and check operation.
GENERATOR INDICATOR
Ignition on, Engine not Running and
Telltale Light Off
1.
Indicator bulb burned out, replace bulb.
2.
Open circuit or loose connection in the telltale light
circuit.
Telltale Light Stays on after Engine is Started
If indicator light does not go out at engine idle speed,
refer to' Charging Systems under Engine Electrical,
Section 6Y.
TEMPERATURE
(COOLING
SYSTEM)
INDICATOR
The temperature indicator circuit, consists of two re-
motely located units, indicator gauge and engine sender
unit. The indicator gauge on all models uses a single
red light to indicate an overheated engine condition.
Engine Sender Unit Replacement
1.
Drain engine cooling system to a level below unit.
2.
Remove sender unit (located in the inlet manifold
near water pump housing on V-8 engines and in the
cylinder head near an exhaust port on L-6 engines)
and replace with new unit.
3.
Refill cooling system and check operation of unit.
CHEVROLET CHASSIS SERVICE MANUAL
ELECTRICAL-BODY
AND
CHASSIS
12-31
CHEVY II INSTRUMENTS AND GAUGES
INDEX
Page
Page
General Description -.....
12-31
Service Operations.
12-31
Instrument Panel
. 12-31
Instrument Cluster
12-31
Fuel Gauge
12-32
12-32
Clock,
Speedometer
12-34
Speedometer Catte
12-34
Indicator Lights
12-34
Oil Pressure Indicator
12-34
Generator Indicator
12-34
Temperature Indicator
12-34
GENERAL DESCRIPTION
The Chevy
n
instrument cluster assembly consists
of:
a speedometer;
a
fuel gauge;
a
generator, temperature
and
oil
pressure indicator lamps, and includes
a
clock
on
deluxe models. Except
for the
speedometer,
all of the
cluster lamps, instruments and gauges
of
the cluster
may
be serviced without removing
the
instrument cluster
as-
sembly from
the
console.
In addition
to the
instrument indicator lamps,
a
brake
warning lamp
is
included
in the
cluster
as
standard
equipment.
The
indicator
is
connected
to
thfc parking
brake and brake pressure differential switches andserves
a dual function.
It
lights when
the
parking brake
is ap-
plied
and
also when
the
brake pedal
is
applied,
if a mal-
function should occur
in the
brake system
due to a
loss
of
hydraulic pressure. Servicing
of the
hydraulic pressure
differential switch
is
covered
in
Section
5 of
this manaul.
Regular maintenance
is not
required on
the
instrument
cluster
or its
components other than r^Mfitftl^i^g clean
and tight electrical connections, replacing defective parts
and keeping
the
speedometer cable properly lubricated.
SERVICE OPERATIONS
INSTRUMENT PANEL
INSTRUMENT CLUSTER
Removal
and
Installation {Figs.
45
thru
48)
1.
Disconnect battery ground cable.
2.
Remove mast jacket upper support clamp (refer
to
Steering, Section
9, for
complete procedure
on low-
ering jacket) and lower steering column.
NOTE:
Apply protective material
to the
mast
jacket
to
prevent damage
to the
painted surfaces.
3.
Disconnect retaining collar securing speedometer
cable
to
speedometer head.
4.
Remove screws retaining cluster
to
console.
5. Pull cluster forward
of
console opening and discon-
nect
all
wiring
and
lamp connections. Remove
cluster from vehicle.
CAUTION:
Do not
pull cluster outward further
than slack
in
wiring harness will allow, other-
Fig.
45-
Instrument Cluster Installation
—
Chevy
II
Fig.
46 -
Speed Warning Device
CHEVtOtET CHASSIS SERVICE MANUAL