1967 CHEVROLET CAMARO tire type

BRAKES

SECTION 5

CONTENTS OF THIS SECTION

Duo Servo Brakes

Disc Brakes
Page

5-1 Power Brakes

5-24 Special Tools
Page

5-31

5-32

DUO-SERVO BRAKES

INDEX

Page

General Description 5-1

Maintenance and Adjustments 5-3

Hydraulic Brake Fluid .. . 5-3

Bleeding Hydraulic System 5-3

Pressure Bleeding 5-3

Manual Bleeding 5_4

Push Rod to Main Cylinder Clearance 5-5

Hydraulic Brake Lines 5-5

Hydraulic Brake Hose 5-5

Hydraulic Brake Tubing 5-6

Brake Adjustment. .................... 5-7

Service Brake 5-7

Parking Brake 5-8

Component Replacement and Repairs 5-9

Parking Brake - Chevrolet, Chevelle and

Camaro 5^9

Pedal Assembly 5-9

Front Cable ,. . . 5-9

Center Cable 5-9

Rear Cables. . 5-9
Parking Brake - Chevy n 5-9

Lever Assembly 5-9

Idler Lever 5-11

Front Cable 5-11

Rear Cable . . ; 5-12

Parking Brake - Corvette 5-13

Lever Assembly . . . . 5-13

Front Cable 5-14

Rear Cable . . 5-14

Brake Pedal 5-15

Shoes and Linings 5-16

Organic 5-16

Metallic 5-17

Main Cylinder 5-18

Wheel Cylinders 5-21

Anchor Pin 5-22

Front Wheel 5-22

Rear Wheel 5-22

Brake Drums • 5-22

Brake Pipe Distribution and Switch Assembly . . . . . 5-23

Camaro Pressure Regulator Valve 5-23

GENERAL DESCRIPTION

All 1967 models are equipped with a new split brake

system as a safety feature. If a wheel cylinder or brake

line should fail at either the front end or rear end of

the vehicle, the operator can still bring the vehicle to

a controlled stop. The system is designed with separate

hydraulic systems for the front and rear brake using

a dual master cylinder (fig. 1). The design of the master

cylinder is similar to that used on the 1966 Corvette

in that it has two entirely separate reservoirs and outlets

in a common body casting. The front reservoir and outlet

is connected to the front wheel brakes, and the rear

reservoir and outlet is connected to the rear wheel

brakes. Two pistons within the master cylinder receive

mechanical pressure from the brake pedal push rod and

transmit it through the brake lines as hydraulic pressure

to the wheel cylinders. The filler cap is accessible from

inside the engine compartment.

A new brake pipe distribution and switch assembly

is mounted below the main cylinder. The front and rear

hydraulic brake lines are routed from the main cylinder,

through the brake pipe distribution and switch assembly,

to the front and rear brakes as shown in Figure 2. The

switch is wired electrically to the brake alarm indicator

light on the instrument panel. In the event of fluid loss

in either the front or rear brake system the indicator

on the instrument panel will illuminate red. (The indi-
cator will also' be illuminated when the parking brake is

applied.)

On Camaro models equipped with air conditioning, the

rear brake hydraulic line is routed through a pressure

regulator valve mounted on the left frame side rail

(fig. 3). The valve controls the hydraulic pressure to

the rear brakes resulting in the correct pressure balance

between the front and rear hydraulic systems.

The self-adjusting brakes (fig. 4), used on both front

and rear of all models, are the Duo-Servo single anchor

type which utilize the momentum of the vehicle to assist

in the brake application. The self-energizing or
self-

actuating force is applied to both brake shoes at each

wheel in both forward and reverse motion. The brake

shoe linings are bonded to the shoes.

Wheel cylinders are the double piston type permitting

even distribution of pressure to each brake shoe. To

keep out dust and moisture, both ejads of each wheel

cylinder are sealed with a rubber booC The wheel

cylinders have no adjustments.

The Chevrolet, Chevelle, and Camaro parking brakes

have a foot operated ratchet type pedal mounted to the

left of the steering column. A cable assembly connects

the pedal to an intermediate cable by means of an equal-

izer, where the adjustment for the parking brake is

incorporated. The intermediate cable attaches to the

CHEVROLET CHASSIS SERVICE MANUAL

BRAKES 5-22

2.
Replace ail push rods and pull back springs.

3.
Connect hose or line to wheel cylinder.

NOTE:
If replacing front wheel cylinder, con-

nect hose and inspect installation as outlined in

"Hydraulic Brake Hose Replacement".

4.
Install drum and wheel.

5. Bleed brakes as outlined in this section.

ANCHOR PIN

Front Wheel

1.
Raise front of vehicle and place on jack stands.

2.
Remove wheel and drum as outlined in this section.

3.
Remove brake shoe pull back springs, link and guide

plate.

4.
Disengage anchor pin lock and remove anchor pin by

turning counterclockwise.

5. Place new lock plate on anchor pin and pass pin

through the hole in flange plate and screw into tapped

hole in spindle support.

6. Torque pin to 130 lb. ft. and lock by peening over

washer tabs.

7. Install brake shoe guide plate, link and pull back

springs.

8. Adjust brakes, install drum and wheel as outlined

in this section. Test brake operation.

Rear Wheel

Two type anchor pins are used in production for the

rear wheels. The riveted type is not serviced and if

failure or damage should occur to either the anchor

pin or flange plate, both parts will have to be replaced

and the threaded type anchor pin used.

Threaded Type

1.
Raise rear of vehicle and place on jack stands,

2.
Remove wheel and drum as outlined in this section.

3.
Remove brake shoe pull back springs, link and guide

plate.

4.
Remove anchor pin retaining nut and washer and

remove pin from flange plate.

5. Position anchor pin to flange plate, install lock

washer and nut, and torque pin to 80 lb. ft.

6. Install brake shoe guide plate, link and pull back

springs.

7. Adjust brakes and install drum and wheel as outlined

in this section.

8. Test brake operation.

BRAKE DRUMS

Front brake drums are the demountable type; that is,

they can be removed without removing the hub. Rear

brake drums are demountable and may be removed

wihtout removing the axle shaft.

A lanced "knock out" area (fig. 34) is provided in

the web of the brake drum for servicing purposes in

the event retracting of the brake shoes is required in

order to remove the drum.

A small screw driver or hooked wire may be inserted

to disengage the automatic adjuster actuating lever so

the star wheel may be turned.

Removal

1.
Raise vehicle and place on jack stand.
2.
Remove wheel and tire assembly, back off brake

adjustment and remove drum.

Inspection and Reconditioning

Whenever brake drums are removed they should be

thoroughly cleaned and inspected for cracks, scores,

deep grooves, and out-of-round. Any of these conditions

must be corrected since they can impair the efficiency

of brake operation and also can cause premature failure

of other parts.

Smooth up any slight scores by polishing with fine

emery cloth. Heavy or extensive scoring will cause

excessive brake lining wear and it will probably be

necessary to rebore in order to true up the braking

surface.

An out-of-round drum makes accurate brake shoe

adjustment impossible and is likely to cause excessive

wear of other parts of brake mechanism due to its

eccentric action.

A drum that is more than .008" out-of-round on the

diameter is unfit for service and should be rebored.

Out-of^round, as well as taper and wear can be ac-

curately measured with an inside micrometer fitted

with proper extension rods.

If drum is to be rebored for use with standard size

brake facings which are worn very little, only enough

metal should be removed to obtain a true smooth braking

surface.

If drum has to be rebored more than .020" over the

standard diameter, it should be rebored to .060" diameter

oversize and the brake facing should be replaced with

.030"
oversize facings.

A brake drum must not be rebored more than .060"

over the maximum standard diameter, since removal

of more metal will effect, dissipation of heat and may

cause distortion of drum. Chevrolet brake facing is

not furnished larger than .030" oversize and this will

not work efficiently in drums bored more than .060"

oversize.

Brake drums may be refinished either by turning or

grinding. Best brake performance is obtained by turning

drums with a very fine feed. To insure maximum lining

life,
the refinished braking surface must be smooth and

free from chatter or tool marks, and run-out must not

exceed .005" total indicator reading.

Cleaning

New brake drums in parts stock are given a light.

coating of rust proofing oil to prevent the formation of

rust on the critical braking surfaces during the time

that the drums are in storage.

This rust proofing oil must be carefully removed

before the drum is placed in service to prevent any

of this oil from getting on the brake shoe facings, which

might cause an extreme brake grab condition.

It is recommended that a suitable volatile, non-toxic,

greaseless type solvent be used to clean the oil from the

braking surface of the new brake drums before they are

•placed in service to insure the cleanest possible surface.

Gasoline or kerosene should not be used as there is

danger that a portion of the diluated oil substance may

be left on the braking surface that may later cause

difficulty.

Installation

1.
Make brake adjustment as outlined in this section.

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-27

timing mark on pulley lines up with timing tab.

2.
Position distributor to opening in block in normal

installed attitude (fig. 15i), noting position of vacuum

control unit.

3.
Position rotor to point toward front of engine (with

distributor housing held in installed attitude), then

turn rotor counter-clockwise approximately 1/8 turn

more toward left cylinder bank and push distributor

down to engine camshaft. It may be necessary to ro-

tate rotor slightly until camshaft engagement is felt.

4.
While pressing firmly down on distributor housing,

kick starter over a few times to make sure oil pump

shaft is engaged. Install hold-down clamp and bolt

and snug up bolt.

5. Turn distributor body slightly until points just open

and tighten distributor clamp bolt.

6. Place distributor cap in position and check to see

that rotor lines up with terminal for No. 1 spark

plug.

7. Install cap, check all high tension wire connections

and connect spark plug wires if they have been re-

moved. It is important that the wires be installed in

their location in the supports.

NOTE:
The brackets are numbered to show the

correct installation. Wires must be installed as

indicated to prevent cross firing.

8. Connect vacuum line to distributor and distributor

primary wire to coil terminal.

9. Start engine and set timing as described under Turn-

Up in Section 6.

BREAKERLESS (MAGNETIC PULSE)

DISTRIBUTOR

REMOVAL (CORVETTE)

1.
If vehicle is equipped with radio, remove three bolts

securing ignition shield over distributor and coil.

One bolt is accessible from the top of shield, the

other two are at rear of shield, facing firewall.

2.
Disconnect tachometer drive cables from distributor

housing.

3.
Disconnect pickup coil leads at connector.

4.
Remove distributor cap.

5. Crank engine so rotor is in position to fire No. 1

cylinder and timing mark on harmonic balancer is

indexed with pointer.

6. Remove vacuum line from distributor.

7. Remove distributor clamping screw and hold-down

clamp.

8. Remove distributor and distributor-to-block gasket.

It will be noted that the rotor will rotate as the

distributor is pulled out of the block. Mark the re-

lationship of the rotor and the distributor housing

after removal so that the rotor can be set in the

same position when the distributor is being installed.

DISASSEMBLY (Fig. 16i)

NOTE:
If a distributor is being disassembled

for replacement of the stationary magnetic

pickup assembly only, it will be necessary to

perform only Steps 3, 4, 5, 7, 8, 9, and 12 of the

service procedure listed below.
1.
Remove screws securing rotor and remove rotor.

2.
Remove centrifugal weight springs and weights.

3.
Remove the tachometer drive gear from the distribu-

tor (Corvette only).

4.
Remove roll pin, then remove distributor drive gear

and washer.

CAUTION: To prevent

magnet, support drive gear
;e to the permanent

?n
driving out roll

pin.

5. Remove drive shaft assembly.

6. Remove centrifugal weight support and timer core

from drive shaft.

7. Remove connector from pickup coil leads.

8. Remove retaining ring which secures magnetic

core support plate to distributor shaft bushing in

housing.

9. As a unit, remove the entire magnetic pickup assem-

bly from the distributor housing.

10.
Remove brass washer and felt pad.

11.
Remove vacuum advance unit.

12.
To reassemble distributor, perform the above steps

in reverse order.

INSTALLATION (CORVETTE)

1.
Check to see that the engine is at firing position for

No.
1 cylinder (timing mark on harmonic balancer

indexed with pointer).

2.
Position a new distributor-to-block gasket on the

block.

3.
Before installing distributor, index rotor with hous-

ing as noted when distributor was removed. Install

distributor in block so that vacuum diaphragm faces

approximately 45° forward on the right side of the

engine and the rotor points toward contact in cap for

No.
1 cylinder.

4.
Replace distributor clamp leaving screw loose

enough to allow distributor to be turned for timing

adjustment.

5. Install spark plug wires in distributor cap. Place

wire for No. 1 cylinder in tower (marked on old cap

during disassembly) then install remaining wires

clockwise around the cap according to the firing

order (1-8-4-3-6-5-7-2).

6. Attach distributor to coil primary wires.

7. Replace distributor cap.

8. Adjust timing and then fully tighten distributor clamp

screw.

9. Attach vacuum line to distributor.

10.
Connect tachometer drive cables to distributor body.

11.
Replace ignition shields.

DISTRIBUTOR OFF-ENGINE TEST

The distributor's centrifugal and vacuum advance can

be checked in a distributor testing machine or synchro-

scope specially adapted or designed to accommodate this

type distributor. However, since this involves removing

the distributor from the engine, this test may be post-

poned until other system checks have been made. A dwell

reading cannot be obtained on this distributor and it is not

likely that the centrifugal or vacuum advance will be a

cause of trouble.

COIL REPLACEMENT

1.
Disconnect ignition switch and distributor leads from

CHEVROLET CHASSIS SERVICE MANUAL

ENGINE-ELECTRICAL 6Y-32

STARTER CIRCUIT

INDEX

Page

General Description 6Y-32

Maintenance and Adjustments . '. . 6Y-32

Resistance Checks 6Y-32

Starting Motor and Solenoid Check 6Y-33
Page

Service Operations 6Y-33

Starter Motor 6Y-33

Removal and Installation 6Y-33

GENERAL DESCRIPTION

The function of the starting system, composed of the

starting motor, solenoid and battery, is to crank the

engine. The battery supplies the electrical energy, the

solenoid completes the circuit to the starting motor, and

the motor then does the actual work of cranking the

engine.

The starting motor (fig. Is) consists primarily of the

drive mechanism, frame, armature, brushes, and field

windings. The starting motor is a pad mounted 12-volt

extruded frame type, having four pole shoes and four
fields,
connected with the armature. The aluminum drive

end housing is extended to enclose the entire shift lever

and plunger mechanism, protecting them from dirt,

splash, and icing. The flange mounted solenoid switch

operates the overrunning clutch drive by means of a

linkage to the shaft lever.

The V-8 wiring harness differs from the in-line engine

in that the ignition lead to the coil from the switch is at-

tached at the coil instead of at the starter solenoid (fig.

2s).

CONTACT

FINGER

PINION

STOP

BRUSH

INSULATED BRUSH HOLDER \ FIELD COIL

BRUSH SPRING ARMATURE

GROUNDED BRUSH HOLDER
OVERRUNNING

CLUTCH

Fig.
Is—Starting Motor Cross Section (Typical)

MAINTENANCE AND ADJUSTMENTS

No periodic lubrication of the starting motor or sole-

noid is required. Since the starting motor and brushes

cannot be inspected without disassembling the unit, no.

service is required on these units between overhaul

periods.

RESISTANCE CHECKS

Although the starting motor cannot be checked against
specifications on the car, a check can be made for. exces-

sive resistance in the starting circuit. Place a volt-

meter across points in the cranking circuit as outlined

below and observe the reading with the starting switch

closed and the motor cranking (distributor primary lead

grounded to prevent engine firing).

1.
From battery positive post To solenoid battery

terminal.

CHEVROLET CHASSIS SERVICE MANUAL

FUEL TANK
AND
EXHAUST SYSTEMS
8-18

CORVETTE

FUEL TANK

INDEX

Page

General Description.
. 8-18

Service Operations
8-18

Fuel Tank
8-18

Gauge Sending Unit
8-20

Fuel Lines.
8-20

GENERAL DESCRIPTION

20 GALLON TANK

Fig.
21
—Corvette Fuel Tanks

The Corvette
is
equipped with
a
standard
20
gallon

(approx.) tank
or an RPO 36
gallon (approx.) fiberglass

tank
(fig. 21). The
tanks
are
installed
at the
very rear

of
the
vehicle, convenient
for
direct fuel filling into
the

tank.
The
tanks
are
held
in
place
by
two metal straps
at-

tached individually
to a
removable
gas
tank frame
sup-

port.
Two
guides
at the end of
the straps
are
adjustable

for securing
the
straps onto
the
tank support. The tank

support
is
secured
to the
frame rail with flat washers,

lockwashers, bolts
and
nuts.
The
tanks' rest
on six
felt

anti-squeak pads.
One pad
centers
on the
rear frame

crossmember
and one at
each side
on the
same cross-

member.
At the
same rear location two pads
are
placed

on
the
tank
at the
metal support strap (rear) attachment
location
and
another anti-squeak
pad
cemented
on the

support
at
the front
of
the tank.

The fuel tanks
are
equipped with
a gas
gauge metering

unit,
a
fuel pickup, fuel strainer
and
vent line.
If it be-

comes necessary,
the
tank
can be
completely drained
by

removing
the
fuel pickup hose which
is
located
at
the
bot-

tom
of the
tank,
or
by removing the metering
for
quicker

draining.

A pressure vacuum type, positive vented design
cap,

conforming
to
I.C.C. regulations,
is
used on both regular

production
and
optional fuel tanks.
The cap is
inter-

changeable with past model tanks
for
service replace-

ment purposes.

SERVICE OPERATIONS

FUEL TANK

CAUTION:
IF THE GAS
TANK SHOULD
BE

REMOVED
AND
INSTALLED, CARE SHOULD

BE EXERCISED
TO
AVOID PUNCTURING,

DROPPING
OR
DENTING
THE GAS
TANK.

Removal
(20
Gallon Tank)

WARNING: FIRST REMOVE BATTERY

CABLE.
1.
Remove
the
spare tire from tire carrier.

2.
Remove spare tire carrier bolted attachments
and

carrier
(fig. 22).

3.
Remove
the "U"
bolt attachments
at
both rear tail

pipe
(See
Figure
23).

4.
Separate
the
exhaust system
at
the transmission sup-

port crossmember
by
loosening
the "U"
bolt nuts.

5. Remove both rear muffler brackets from
the
frame

and slide
the
muffler system rearward.

CHEVROLET CHASSIS SERVICE MANUAL

FUEL TANK AND EXHAUST SYSTEMS 8-20

4.
Attach the retaining straps with strap guide attached

to the fuel tank support, and secure with-the nut and

lockwasher assembly.

5. Connect the filler neck boot to the drain hose of the

tank and install boot around filler neck,

6. Connect the fuel pickup line, ground wire and make

certain that the fuel drain line is flush to 1/2" in-

board of the rear bumper opening.

7. Attach tank metering unit wires (fig. 25).

8. Replace fuel in tank. Replace gas cap.

9. Check for possible leaks.

10.
Reconnect the exhaust system by reversing the above

removal procedures (see "Exhaust System").

11.
Install spare tire carrier by securing the bolt

attachment.

12.
Install the spare tire in the tire carrier.

Removal (36 Gallon Tank)

1.
Remove cover (fig. 26).

2.
Disconnect hoses and drain tank and remove two

fittings at bottom of tank.

3.
Disconnect fuel and vent lines and wires at tank

(fig. 27).

4.
Remove straps.

installation (36 Gallon Tank)

Reverse removal procedure to install.

FUEL TANK METERING UNIT OR GAUGE

SENDING UNIT AND STRAINER

The fuel tank metering unit is located at the bottom of

the fuel tank. The fuel strainer is attached at the end of

the sending unit inside the tank.

Replacement (20 Gallon Tank)

1.
Follow fuel tank removal procedure through Step 2.

2.
Drain the tank. Disconnect the attaching wires.

3.
Remove metering unit with a fuel tank gauge unit

Spanner J-8950 (revised).

4.
'Remove metering unit and gasket.

CAUTION: Carefully remove unit so as not to

damage screen on the end of the pipe.

5. Clean strainer screen by blowing out with com-

pressed air.

6. Reverse procedure to install.

Replacement (36 Gallon Tank)

1.
Remove cover.

2.
Follow Steps 2 thru 6 as outlined under replacement

for 20 gallon tank.

FUEL LINES

20 Gallon Tank

The fuel lines are conveniently located along the out-

side of the right frame rail (fig. 28). The lines extend
Fig.
26—Gasoline Tank (36 Gallon) Compartment Cover

from the fuel tank pickup at the bottom of the tank, along

the rear frame crossmember to the right frame rail,

extending through the rail at the kickup area and along the

top inside edge of the frame to the fuel pump, Flexible

hoses are located at the fuel tank pickup and at the fuel

pump.

36 Gallon Tank

The 36 gallon tank fuel lines are routed from the bot-

tom of both sides of the tank to the right frame rail

(fig. 20).

Maintenance

CAUTION: Always drain gasoline from the

complete fuel system including carburetor, fuel

pump and all fuel lines and fuel tank if the vehi-

cle is to be stored for any great length of time.

This precaution will prevent accumulation~ol

gum formation and resultant poor engine

performance.

. The fuel lines should occasionally be inspected for

leaks,
kinks or dents, especially when work has been

done on the underside of car or after the car has been

traveling over rough or stone roads at higher speeds.

If evidence of dirt is found in the carburetor or fuel pump

at disassembly, the lines should be disconnected and

blown put. Check the fuel tank strainer for damage or

omission.

Fuel lines are beaded-type ends for connection to

hoses and flared ends for secure metal-to-metal line

connections.

CHEVROLET CHASSIS SERVICE MANUAL

STEERING 9-34

Fig.
64-Over Center Adjustment

transmission fluid "Type A" bearing the mark

"AQ-ATF" followed by a number and the suffix

letter "A".

ADJUSTMENTS

POWER STEERING GEAR

Chevrolet, Chevelle, and Camaro

The over-center adjustment (fig. 64) is the only power

steering gear adjustment which can be made on the car.

However, in order to make this adjustment, it is also

necessary to check the combined ball and thrust bearing

preload.

If the vehicle is equipped with a tilt column it will be

necessary to disconnect the steering coupling to obtain a

torque reading of the column. This torque should then be

subtracted from any reading taken on the gear.

1.
Disconnect the pitman arm from the relay rod.

2.
Loosen the pitman shaft adjusting screw loeknut and

thread the adjusting screw out to the limit of its

travel through the side cover. '. •

3.
Disconnect steering column harness at chassis wir-

ing connector plug.

4.
Remove horn button.

5.
Turn the steering wheel through its full travel, then

locate the wheel at its center of travel.

6. Gheck the combined ball and thrust bearing preload

with an inch-pound torque wrench on the steering

shaft nut by rotating through the center of travel

(approximately 1/4 turn in each direction). Note the

highest reading.

7.
Tighten the pitman shaft adjusting screw and check

torque at steering shaft nut until over center preload

and total steering gear preload falls within speci-

fications. Refer to torque specifications at rear of

manual for correct torque values.

8. Install horn button. Connect steering column harness

at wiring connector plug.
Chevy II and Corvette

The steering gear used with power steering is adjusted

in the same manner as the manual steering gear.

PUMP BELT TENSION

1.
Loosen nut on pivot bolt and pump brace adjusting

nut.

CAUTION: Do not move pump by prying against

reservoir or by pulling on filler neck.

2.
Move pump, with belt in place until belt is tensioned

to specifications as indicated by Tool J-7316 (Fig-.

65).

3.
Tighten pump brace adjusting nut. Then tighten pivot

bolt nut.

HYDRAULIC SYSTEM CHECKS

The following procedure outlines methods to identify

and isolate power steering hydraulic circuit difficulties.

This test is divided into two parts. Test number one

provides means of determining whether power steering

system hydraulic parts are actually faulty. If test number

one results in readings indicating faulty hydraulic opera-

tion, test number two will identify the faulty part. Be-

fore performing hydraulic circuit test, carefully check

belt tension and condition of driving pulley. Strand

tension of belt should be 125 lbs. on new belts and 75 lbs.

on old belts, as indicated by Tool J-7316 (Fig. 65).

Test Number One—Oil Circuit Open

Engine must be at normal operating temperature. In-

flate front, tires to correct pressure. All tests are made

with engine idling, so adjust engine idle speed to correct

specifications listed in Section 6 and proceed as follows:

a. With engine not running, disconnect flexible pres-

sure line from pump and install Tool J-5176 as

Fig.
65— Checking Belt Tension with Tool J-7316

CHEVROLET CHASSIS SERVICE MANUAL

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