Ford 1956 Truck Shop Manual

Copyright © 2011, Forel Publishing Company, LLC, Woodbridge, Virginia

All Rights Reserved. No part of this book may be used or reproduced in any manner whatsoever

without written permission of Forel Publishing Company, LLC. For information write to Forel

Publishing Company, LLC, 3999 Peregrine Ridge Ct., Woodbridge, VA 22192

1956 Ford Truck Shop Manual

EAN: 978-1-60371-065-7

ISBN: 1-60371-065-5

Forel Publishing Company, LLC

3999 Peregrine Ridge Ct.

Woodbridge, VA 22192

Email address: [e-mail]

Website: http://www.ForelPublishing.com

This publication contains material that is reproduced and distributed under a license from Ford

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allowed without the express written permission of Ford Motor Company.

Note from the Publisher

This product was created from the original Ford Motor Company’s publication. Every effort has
been made to use the original scanned images, however, due to the condition of the material;
some pages have been modified to remove imperfections.

Disclaimer

Although every effort was made to ensure the accuracy of this book, no representations or
warranties of any kind are made concerning the accuracy, completeness or suitability of the
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195&

Copyright

1955

FORD

MOTOR

COMPANY

DEARBORN.

MICHIGAN

All rilthts

reserved

September,

1955

FOR

D D

IVI

5

ION

FOR

0

MOT

0 R

COMPA

NY

FOREWORD

This

manual

has

been

prepared

to

provide

infonnation

for

the

proper

servicing

of

1956

Ford

Trucks.

The

manual

should

be

kept

where

it

will

be

readily

available

for

reference

at

all times.

The

service

procedures

are

accompanied

by

illustrations

of

many

of

the

service

operations.

Disassembled

views

of

some

of

the

truck

units

are

also given.
The

manual

is

divided

into

five

main

parts

as

listed

in

the

Table

of

Contents

on

the

following pages.

Part

ONE-POWER

PLANT-is

composed

of

the

various

truck

engines

and

their

related

systems,

which

are,

the

ignition, fuel,

and

cooling

system.

Part

TWO -CHASSIS

- includes

information

on

the

entire

power

train

(clutch,

conventional

transmission,

Overdrive,

drive

lines,

rear

axles,

etc.)

and

the

running

gear

(frames,

springs,

suspen-

sion,

brakes,

wheels, tires,

steering

gear,

steering

linkages,

etc.).

S~rvice

procedures

for

the

Fordomatic

transmission

are

published

in a separate

manual.

Part

THREE -ELECTRICAL

AND

ACCESSORIES -covers

all of

the

electrkal

systems

and

units

(except

the

ignition

system)

and

all

of

the

accessories

(except

the

Overdrive

and

Fordomatic).

Part

FOUR -BODIES -contains

information

on

the

mainte-

nance

and

repair

of

all

body

components,

including

adjustment

and

alignment

of doors, hoods,

and

fenders.

Window

glass

adjustments

are

also

included

in

this

part.

Part

FIVE -MAINTENANCE

AND

SPECIFICATIONS-

includes

complete

maintenance

and

lubrication

infonnation,

and

contains

all

the

specifications

necessary

for

properly

servicing

Ford

trucks.

The

page

headings,

throughout

the

manual,

designate

the

subject

matter

covered.

The

heading

on

each

left-hand

or

even-numbered

page

indicates

the

name

of

the

chapter

and

the

heading

on

each

right-hand

or

odd-numbered

page

indicates

the

section

covered.

The

descriptions

and

specifications

contained

in

this

manual

were

in

effect

at

the

time

the

book

was

approved

for

printing.

The

Ford

Division

of

Ford

Motor

Company

reserves

the

right

to

dis-

continue

models

at

any

time,

or

change

specifications

or

design,

without

notice

and

without

incurring

obligation.

SERVICE

DEPARTMENT

FORD

DIVISION

FORD

MOTOR

COMPANY

TABLE

OF

CONTENTS

Foreword

.................................................

.

Part

ONE-PO\VEH

PLA~T

CHAPTER

I-GENERAL

ENGINE

OVERHAUL,

INSPECTION,

AND

REPAIR

Sertion

Pa/l:~

~~

..

tion

1

Trouble

Shooting

.............

5 6

Timing

Chain

and

Sprockets,

Timing

Gears

and

2

Tune-Up

...

..........

8

Camshaft

3

Engine

Removal

and

Installation

....

10

7

Flywheel,

Crankshaft,

and

Main

Bearings

8

Cylinder

Block,

Pistons,

Piston

Rings,

and

4

Intake

and

Exhaust

Manifolds.

15

Connecting

Rods

and

Bearings

..

5

Rocker

Mechanisms,

Cylinder

Heads,

Valves, Valve

9

Oil

Pan

and

Oil

Pump

Lash

Adjustment

and

Valve

Timing

.............

15

10

Exhaust

System

...

CHAPTER

II-6-CYLINDER

ENGINE

1

Manifolds.

.........

.

...................

33

6

Flywheel,

Crankshaft,

and

Main

Bearings

..

2

Cylinder

Head

and

Valves

......

34 7

Connecting

Rods

and

Bearings,

Pistons,

Pins,

3

Crankshaft

Damper

...........

37

and

Rings

4

Cylinder

Front

Cover

and

Crankshaft

Oil Seal

......

38

8

Oil

Pan,

Oil

Filter,

and

Oil

Pump

5

Sprockets

and

Timing

Chain,

Camshaft

and

9

Exhaust

System

..

Bearings

and

Tappets

...........

..........

38

CHAPTER

III-8-CYLINDER

ENGINES

1

General

Information.

49

7

Sprockets

and

Timing

Chain,

Timing

Gear,

2

Engine

Front

Support

....

50

Camshaft

and

Bearings,

and

Tappets

.......................

8

Flywheel,

Crankshaft,

and

Main

Bearings

..

3

Manifolds

..

.........................

.

.........

50

9

Connecting

Rods

and

Bearings,

Pistons,

Pins,

4

Cylinder

Head

and

Valves

.......

................

52

and

Rings.

5

Crankshaft

Damper

..

....................

55

10

Oil

Pan,

Oil

Filter,

and

Oil

Pump.

6

Cylinder

Front

Cover

and

Crankshaft

Oil Seal

......

56

11

Exhaust

System

..

CHAPTER

IV-IGNITION,

FUEL,

AND

COOLING

SYSTEMS

1

Ignition

System

.......

.

8

Four

Barrel

Carburetor

Operation,

Adjustments,

Page

2.

PU/l:e

21
23

27
31
32

41
43

45
47

57
62

66
68

70

2

Distributor

Minor

Repair

and

Adjustments

......

.

73
78

80

and

Overhaul.

.........

102

3

Distributor

Overhaul

.........

.

4

Carburetor

Operation

and

Adjustments-

Single,

Dual,

and

Dual

Concentric

Carburetors

..

5 Single

Barrel

Carburetor

Overhaul

....

.

6

Dual

Carburetor

Overhaul

........

.

7

Dual

Concentric

Carburetor

Overhaul

...

86

92
95
97

9

Fuel

Tanks

and

Lines.

111

10

Fuel

Pump,

Vacuum

Boosters,

and

Fuel

Filter.

112

11

Governors..

116

12

Fans

and

Belts.

..

.........

118

13

Water

Pumps.

. . . . . 119

14

Cooling

System-Radiator,

Hose,

and

Thermostat..

122

Part

TWO-CHASSIS

CHAPTER

I-CLUTCH,

TRANSMISSION,

AND

GEAR

SHIFT

LINKAGE

1

Trouble

Shooting

.............................

126 7

4-Speed

Transmission

.......

2

Clutch

..........................

.........

127 8

Light-Duty

5-Speed

Transmissions

3

Flywheel

Housing

Alignment

..........

131

9

Medium-Duty

and

Heavy-Duty

5-Speed

4

Transmission

Cleaning

and

Inspection.

133

Transmissions.

5

3-Speed

Transmissions

...........

134

10

3-Speed

Au~iliary

Transmission

6

Overdrive

Transmission

.......

.........

139

11

Gear

Shift

Linkage.

CHAPTER

II-REAR

AXLES

AND

DRIVE

LINES

1

Trouble

Shooting

..........................

.

2 Cleaning

and

Inspection

.............

.

3

Integral

Housing

Hypoid

Rear

Axles

....

.

4

Banjo

Housing

Hypoid

Rear

Axles. .

........

.

169
170
172
180

5

Banjo

Housing

Spiral

Bevel

Rear

Axles

6

Two-Speed

Planetary

Rear

Axles

..

7

Drive

Lines

....

CHAPTER

III-TANDEM

REAR

AXLES

1

Construction

..............................

.

2

Operation....................

.

...........

.

207
210

3

Replacement.

4

Overhaul.

148
152

lSi

164

168

187
191
203

211
218

CHAPTER

IV-RUNNING

GEAR

~~("tion

1

Trouble

Shooting

..

.

2 Wheel Alignment

......

.

3

Frames

....

4

Front

Axles

....

5 Springs

233

235
237
239
242

SeC"tion

I'al(~

6 Shock Absorbers. . . . . . . . . . . . . . . . . . . . . .

243

7 Steering

Gear.

. . . . . . . . . . . . . . . . . . . . . . . . . . .

244

8 Steering

Linkage.

...........

. . . . . . . . . . . . . . .

..

246

9 Wheels

and

Tires. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..

248

10

Hubs

and

Bearings

..............................

250

CHAPTER

V-POWER

STEERING

1

Construction

and

Operation

............

255

3

Overhaul.......................................

264

2 Inspection

and

Trouble

Shooting

..................

261

CHAPTER

VI-BRAKES

1 Trouble Shooting

................................

273

5 Air

Brakes

.....................................

307

2

Hydraulic

Brakes

...............................

276

6

Brake

Drums

...................................

314

3

Vacuum

Boosters

................................

287

7

Parking

Brakes

.................................

315

4

Air-Hydraulic

Unit.

. . . . . . . . . . . . . . . . . . . . . . . . . . .

..

302

Part THREE-ELECTRICAL AND ACCESSORIES

CHAPTER

I-GENERATING

SYSTEM

AND

BATTERY

1

Trouble

Shooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..

317

3

Generator

Regulator

.............................

326

2

Generator

......................................

321

4

Battery........................................

332

CHAPTER

II-STARTING

SYSTEM

1

Trouble

Shooting

...............................

, 335 3

Starter

Drive.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..

344

2

Starter

and

Circuit

.............................

, 338

CHAPTER

III-LIGHTING

SYSTEM,

HORNS,

AND

INSTRUMENTS

1 Trouble Shooting

................................

345 3

Horns

..........................................

352

2 Lighting

System.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..

348 4

Instruments....................................

354

CHAPTER

IV

-ACCESSORIES

1 Trouble Shooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..

359 3

Heater.........................................

366

2

Radio

..........................................

362 4 Miscellaneous Accessories. . . . . . . . . . . . . . . . . . . . . .

..

368

Part

FOUR-BODIES

AND CABS

CHAPTER

I-BODY

CONSTRUCTION

AND

MAINTENANCE

Construction

Details

and

Sealer

Application.

. . . . .

..

371

2 General

Body

Maintenance

.......................

376

CHAPTER

II-INTERIOR

TRlrw:,

HARDWARE,

AND

GLASS

1 Seats

and

Interior

Trim

.........................

, 377

2 Window

Regulator

and

Glass

Replacement.

. . . . . .

..

381

3 Glass

Adjustments.

. . . . . . . . . . . . . . . . . . . . . . . . . . .

..

385

4 Door Locking

Mechanism.

. . . . . . . . . . . . . . . . . . . . .

..

385

5 Windshield

and

Back

Window.

. . . . . . . . . . . . . . . . .

..

390

CHAPTER

III-REMOVABLE

SHEET

METAL

ASSEMBLIES

1

Front

End

Sheet

Metal.

. . . . . . . . . . . . . . . . . . . . . . .

..

393 4

Hood..........................................

396

2

Fenders........................................

394 5

Doors..........................................

398

3 Cowl

Ventilator.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..

396 6

Running

Boards.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..

400

Part FIVE-MAINTENANCE AND SPECIFICATIONS

CHAPTER

I-MAINTENANCE

1

Preventive

Maintenance

.........................

403 2

Lubrication.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..

404

CHAPTER

II

-SPECIFICATIONS

1 Wheels

and

Tires. . . . . . . . .

..

....................

409

2

Brakes

.........................................

410

3 Wheel Alignment

and

Steering.

. . . . . . . . . . . . . . . . .

..

411

4

Rear

Axle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

..

413

5

Springs

........................................

415

6 Engines

........................................

416

7

Clutch

and

Transmission

.........................

419

8 Cooling

System

.................................

421

9

Fuel

System

....................................

421

10

Generating

System

..............................

421

11

Starting

System

.................................

422

12

Ignition........................................

422

13

Wiring

Diagram

.................................

424

14

Paint

..........................................

425

15

Bulb

Chart

.....................................

425

16

Tools

and

Equipment

...........................

, 426

Part

ONE

POWER

PLANT

Chapter

General Engine Overhaul, Inspection,

and

Repair

Section

Page

1

2

3

4

5
6
7

8

9

Trouble

Shooting

...................................................................

.

5

8

10
15
15

21

23

27

31

32

Tune-Up

..........................................................................

.

Engine

Removal

and

Installation

.......................................................

.

Intake

and

Exhaust

Manifolds

.........................................................

.

Rocker

Mechanism,

Cylinder

Heads,

Valves,

Valve

Lash

Adjustment,

and

Valve

Timing

.........

.

Timing

Chain

and

Sprockets,

Timing

Gears,

and

Camshaft

..................................

.

Flywheel,

Crankshaft,

and

Main

Bearings

...............................................

.

Cylinder

Block,

Pistons,

Piston

Rings,

and

Connecting

Rods

and

Bearings

...................

.

Oil

Pan

and

Oil

Pump

...............................................................

.

10

Exhaust

System

.....................................................................

.

Trouble

shooting;

tune-up;

the

cleaning,

inspection,

and

repair

of

component

parts;

and

overhaul

instructions

are

covered

in

this

chapter.

The

cleaning,

inspection,

repair,

and

overhaul

instruc-

tions

apply

only

after

the

parts

have

been

removed

from

the

engine,

or

in

the

case

of a complete

overhaul

after

the

engine

has

been

disassembled.

To

completely

disassemble

or

assemble

an

engine,

fol-

low all

the

removal

or

installation

procedures

contained

in

the

applicable

engine

chapter.

If

it

is

only

desired

to

remove

and

install

an

individual

part,

refer

to

the

ap-

plicable

section.

1.

TROUBLE

SHOOTING

Trouble

shooting

is

the

application

of a definite

pro-

cedure,

in a logical

sequence,

to

locate

and

eliminate

the

cause

of

trouble

in a particular

system

or

unit.

When

trouble

shooting,

first

look

for

the

obvious

causes

of

trouble,

such

as;

an

empty

gas

tank, a wet

or

cold

engine,

loose

or

disconnected

wiring,

or

any

other

item

that

may

cause a temporary

defect.

The

various

factors

that

affect

power

plant

operation

are

outlined

in

this

section.

a.

Engine.

Poor

engine

performance

can

be

attributed

to

the

engine

or

to

forces

on

the

truck

that

tend

to

retard

its

motion.

For

example,

dragging

brakes

can

cause

the

engine

to

work

harder

which

will

result

in

poor

performance.

Engine

performance

depends

on

proper

fuel

distribu-

tion,

correctly

timed

ignition,

normal

and

uniform

com-

pression,

and

an

unobstructed

flow

of

exhaust

gases.

Engine

troubles,

their

causes,

and

remedies

are

dis-

cussed

under

appropriate

headings.

(1)

ENGINE

WILL

NOT

CRANK.

If

the

starter

does

not

turn

the

engine

over,

or

turns

it

over

too

slowly

5

to

start,

the

most

probable

causes

are a defective

battery

or

starter.

Perform

the

following

checks

in

the

order

listed,

until

the

trouble

is

located.

(a)

CHECK

THE

BATIERY.

Try

the

horn

or

lights.

If

they

do

not

operate

properly,

test

the

battery.

Recharge

or

replace

the

battery

as

necessary.

(b)

CHECK

THE

BA

TIERY

CABLES.

Check

for

loose

or

corroded

connections

at

the

starter,

starter

relay,

bat-

tery,

and

ground.

Clean,

tighten,

or

replace

them

as

necessary.

(c)

CHECK

THE

STARTER

RELAY CIRCUIT.

The

starter

relay

contact

surfaces

seldom

become

so

badly

burned

that

they

will

prevent

the

starter

from

cranking

the

en-

gine.

However,

other

wiring

may

be

at

fault.

Repair

as

necessary.

Refer

to

Part

Three

"Electrical

and

Acces-

sories."

(

d)

CHECK

THE

STARTER

OR

STARTER

DRIVE.

If

the

above

components

are

not

at

fault,

the

trouble

is

proba-

bly

in

the

starter

or

starter

drive.

If

the

starter

is

run-

ning,

but

not

engaging

the

flywheel,

remove

the

starter

and

make

the

necessary

repairs

to

the

starter

drive.

In

rare

cases,

the

starter

drive

may

lock

up

with

the

fly-

wheel.

This

can

be

corrected

by

loosening

the

starter

and

releasing

the

starter

drive.

If

the

starter

does

not

6

Chapter

l-General

Engine

Overhaul,

Inspection,

and

Repair

operate,

remove

it

and

make

the

necessary

repairs.

(2)

ENGINE

CRANKS,

BUT

W'U,L

NOT

START.

The

trouble

probably

lies in

either

the

ignition

system

or

the

fuel

system.

The

following

test

will

determine

which

system

is

at

fault.

Remove

the

ignition

wire

from

one

spark

plug,

and

insert a piece

of

proper

sized

drill

rod

so

it

protrudes

from

the

insulator.

With

the

ignition

on

and

the

starter

turning

the

engine

over,

hold

the

end

of

the

rod

ap-

proximately

~)

6

inch

from

the

block.

CAUTION:

On

Fordomatir

equipped

trucks,

make

&ure

the

selector

lever

is

in

~'N."

If

there

is

no

spark

or

if

there

is a

weak

spark,

follow

steps

"a"

or

"b"

whichever

is

applicable.

If

there

is a

good

spark,

proceed

with

step

"c."

(a)

No

SPARK.

Follow

the

steps

below

to

determine

the

cause

and

make

the

necessary

repairs

or

replace-

ments.

(

1)

Pull

the

coil

wire

from

the

top

of

the

distribu-

tor.

Hold

the

wire

:i,tti

inch

from

the

cylinder

head,

'lnd

with

the

ignition

on

and

the

engine

turning

over,

check

for a

spark.

CAUTION:

On

Forclomatic

equippecl

trucks,

make

sure

the

selector

lever

is

in

HN."

If

a

good

spark

is

obtained,

the

trouble

lies

in

either

the

distributor

cap,

rotor,

or

spark

plug

wires.

Make

sure

these

components

are

clean,

dry,

and

not

defective.

Make

repairs

or

replacements

as

necessary.

(2)

If

there

was

no

spark

in

(1)

clean

the

coil

tower

socket

and

replace

the

high

tension

wire

between

the

coil

~nd

the

distributor,

then

repeat

the

check.

If

a

weak

spark

exists,

the

points

are

probably

arcing.

Test

the

condenser

and

replace

it

if

necessary.

Adjust

the

points.

If

a

weak

spark

persists,

test

the

coil

and

replace

it

if

necessary.

(3)

If

there

was

no

spark

in

(2),

remove

the

dis-

tributor

cap

a1"ui

see

if

the

points

are

"breaking"

and

if

an

electrical

spark

occurs

at

the

points.

Adjust

or

replace

the

points

as

necessary.

If

there

is a

spark

at

the

points,

and

they

open

properly,

the

secondary

circuit

of

the

coil

is

defective.

If

there

is

no

spark

at

the

points,

install

a

"jumper"

between

the

"Dist"

terminal

of

the

coil

and

the

distributor,

then

check

for a spark

at

the

points.

If

there

is a

spark,

replace

the

coil

to

distributor

primary

wire.

If

there

is

no

spark,

crank

the

engine

until

the

points.

Gire

closed,

then

install a "jumper"

on

one

of

the

primary

coil

terminals

and

check

for a spark

at

the

other

terminal.

Replace

the

coil if

there

is

now a spark.

If

there

is

no

spark,

install a "jumper"

between

the

battery

and

the

battery

terminal

of

the

coil,

then

check

for a

spark

at

the

points.

If

there

is a

spark,

the

ignition

switch

or

switch

to

coil

wiring

is

defective

and

must

be

repaired

or

replaced.

(b)

WEAK

SPARK.

Perform

the

following

checks

in

the

order

listed:

(

1)

Test

the

battery,

then

charge,

or

replace

it

as

necessary.

(2)

Remove

the

distributor

cap,

and

check

the

condition

of

the

points.

Adjust,

clean,

or

replace

them

as

necessary.

Severely

pitted

points

usually

indicate

that

the

voltage

regulator

is

improperly

set

or

the

condenser

is

faulty.

(3)

Check

the

condition

of

the

rotor,

distributor

cap,

and

plug

wires.

The

wires

must

be

clean,

dry,

and

fully

seated

in

the

terminals.

Replace

any

damaged

or

corroded

wire.

(

4)

If

the

weak

spark

persists,

test

the

coil

and

replace

it

if

necessary.

(c)

GOOD

SPARK.

If

there

is a

good

spark,

perform

the

following

fuel

system

checks

in

the

order

given.

(

1)

Check

the

fuel

supply

at

the

tank.

(2)

Check

to

see

if

fuel

is

reaching

the

carburetor.

Remove

the

air

cleaner,

and

look

down

the

carburetor

throat

while

working

the

throttle

by

hand

several

times.

Each

time

the

throttle

is

actuated

fuel

should

spurt

from

the

accelerator

pump

discharge

nozzle.

If

there

is fuel

at

this

point,

the

engine

is

probably

flooded

or

there

is

water

in

the

fuel

system.

If

no

fuel is

observed

at

this

point,

disconnect

the

carburetor

inlet

line

at

the

car-

buretor.

Using a suitable

container

to

catch

the

fuel,

crank

the

engine

to

see

if

fuel

is

reaching

the

inlet

fitting.

If

fuel is

reaching

the

inlet

fitting,

the

trouble

is in

the

fuel

pump

or

the

fuel

inlet

line

is

clogged.

NOTE:

Check

the

flexihle

gas

line

for a collapsed

conclition.

Remove

the

fuel

tank

filler

cap,

then

disconnect

the

fuel

pump

inlet

line

at

the

pump.

Blow

air

into

the

line

to

remove

any

obstructions.

Connect

the

line

and

try

to

start

the

engine.

If

the

engine

does

not

start,

check

the

fuel

pump

pressure,

then

repair

or

replace

the

pump

as

necessary.

(3)

ENGINE.

STARTS,

BUT

FAILS

TO

KEEP

RUNNING.

Check

the

fuel

system

first.

The

ignition

system

sometimes

can

cause

trouble,

but

it

is

usually

after

the

engine

has

run

for

some

time

and

is

at

operat-

ing

temperature.

(a)

Check

the

fuel

supply

at

the

tank.

(b)

Try

to

start

the

engine.

If

the

engine

will

operate

with

constant

foot

throttle,

ad

just

the

idle

speed

and

check

the

choke

adjustment.

If

it

will

not

operate

with

constant

foot

throttle,

check

the

fuel

system

as

outlined

in

(2)

(c).

(c)

If

the

fuel

system

is

operating

correctly

and

the

engine

still stalls,

it

may

be

due

to

the

coil

or

condenser

breaking

down

under

operating

temperature.

Check

these

components

and

replace

them

as

necessary.

Section 1-Trouble Shooting

7

(4)

f.;I\'l;//'iE

COIVTIlVUAl~I

.. Y l""SSES

AT

IDLE.

When

the

engine

continually

misses

on

the

same

cylin-

ders,

the

fault

generally

lies

in

the

ignition

system.

(a)

Isolate

the

miss

by

pulling

one

spark

plug

cable

at a time

from

the

plugs.

Remove

the

plugs,

then

clean,

inspect.

and

adjust

them.

Replace

those

that

are

badly

fouled

or

burned.

(b)

Check

the

spark

plug

wires

for

signs

of

deteriora-

tion

and

corrosion

and

replace

them

as

necessary.

(c)

Remove

the

distributor

cap

and

rotor,

then

clean,

inspect,

and

replace

them

as

necessary.

(d)

If

the

above

steps

do

not

correct

the

condition,

check

the

compression

to

determine

if

it

is

satisfactory,

and

check

the

intake

manifold

for

obstructions.

(5)

E/\'GilVE ,U/SSES

f:RRATICALLY

AT

Il)LE.

A miss of

this

type

may

be

caused

by a combination

of

things.

Check

the

following

in

sequence:

(a)

Carburetor,

including

choke

operation,

idle

mix-

ture

setting,

and

fuel

level.

(b)

The

ignition

system

starting

with

the

spark

plugs.

(c)

The

vacuum

lines

and

fittings

for

leaks.

(d)

Valve

operation.

Perform a compression

test

if

the

miss

persists.

Repair

the

engine

as

necessary.

(6)

E."i(;INE

.U/.~f'IRf;S

OR

Hf;SITATES

ON

AC·

Cf:/~f;R.4.TI01".

This

malfunction

is

usually a combina-

tion

of

faults

in

the

ignition

and

fuel

system,

but

also

can

be

caused

by

the

exhaust

system.

Perform

the

fol-

lowing

checks

in

the

sequence

given:

(a)

Check

the

operation

of

the

exhaust

gas

control

valve.

If

it is

sticking,

free

it

up

or

replace

it

as

necessary.

(b)

Check

the

paint

on

the

intake

manifol~

heat

riser

passage.

If

the

paint

is

not

burned

off,

the

passage

may

be

obstructed

preventing

the

carburetor

from

properly

vaJ:orizing

the

fuel.

(c)

Remove

the

spark

plugs.

Inspect,

clean,

and

ad-

just

the

gap.

Replace

any

plugs

that

are

defective

(Jr

lead

fouled.

(d)

Remove

the

distributor

cap

and

check

the

point

gap,

distributor

shaft

clearance,

condition

of

the

cam

lobes,

and

the

points.

Make

the

necessary

repairs

or

re-

placements.

Check

the

high

tension

wiring

for

signs

of

deterioration,

and

make

repairs

or

replacements

as

necessary.

(e)

Check

the

coil

and

condenser.

Replace

them

if

they

are

defective.

(f)

Check

the

fuel

pump

pressure

and

adjust

the

car-

buretor

fuel level.

Check

the

accelerator

pump

action

and

linkage.

(g)

If

the

problem

still

persists,

perform a compres-

sion

test

and

check

the

valve

lash.

Check

the

valve

spring

rates

and

assembled

height.

Make

repairs

or

re-

placements

as

necessary.

(7)

f;,\,(;II\'f; IJOf;S

NOT

Hf;V

f;/

..

OP

f'LJ

/./.

PO"" f;R.

Lack

of

power

is

usually

caused

by

poor

'1ression.

However,

some

preliminary

checks

should

be

made.

Make

sure

the

throttle

opens

all

the

way,

that

the

choke

remains

open,

and

that

the

governor

cut-off

operates

properly.

After

preliminary

checks

are

made,

perform

the

following

operations

if

the

trouble

has

not

been

located.

(a)

Check

the

compression.

This

wil1

indicate

whether

the

internal

components

are

operating

properly.

(b)

If

the

compression

checks

within

limits,

check

the

ignition

system,

including

initial

timing

and

distributor

operation.

(c)

If

the

compression

and

the

ignition

system

are

satisfactory,

check

the

fuel

system,

including

carburetion

and

fuel

pump

pressure.

(d)

If

the

problem

still

exists, a

check

of

mechanical

components

must

be

made.

Check

the

valve

lash,

cam

lobe, lift,

and

valve

timing.

Make

the

necessary

repairs.

b.

Fuel

System.

The

fuel

system

consists

of

the

fuel

tank,

fuel

pump,

carburetor,

and

connecting

lines.

Dirt

and

other

foreign

material

are a major

source

of

fuel

system

problems.

Keep

all

components

as

clean

as

possible.

(1)

EXCESSIJ'E

FUEL

COI,'SUMPTION.

Faulty

carburetion

is

usually

responsible

for

excessive

fuel con-

sumption.

However,

the

following

preliminary

checks

should

be

made.

Check

for fuel

leaks

in

the

system.

Check

choke

opera-

tion

and

adjustment.

and

make

certain

the

accelerator

linkage

is free.

Check

to

see

if

the

brakes

are

dragging.

Adjust

the

carburetor.

(a)

Verify

the

complaint

with

test

equipment

installed

in

the

truck.

Show

the

customer

how

improper

operation

of

the

truck

will

affect

fuel

consumption.

(b)

If

the

test

shows

fuel

consumption

to

be

excessive,

rebuild

the

carburetor.

Since

poor

carburetion

is

usually

a

combination

of

internal

malfunctions,

it is

usually

not

advisable

to

try

to

repair

only

one

system

in

the

car-

buretor.

Time

will

be

saved

by a complete

carburetor

overhaul.

(2)

CARIlURETOR

Fl

..

OODS.

Make a visual

in-

spection

of

the

carburetor

for

leaking

gaskets

or

casting

defects.

Tap

the

carburetor

bowl.

If

the

flooding

stops.

the

inlet

needle

was

held

open

by

foreign

material.

If

the

flooding

persists,

follow

the

steps

below:

(a)

Remove

the

air

cleaner

and

check

the

choke

operation,

(b)

Check

the

fuel level,

the

condition

of

the

car-

buretor

float,

and

the

fuel

inlet

needle

and

seat.

Replace

any

defective

parts.

(c)

Check

fuel

pump

pressure.

If

the

pressure

is ex-

cessive,

the

pump

was

forcing

fuel

past

the

fl0at

needle.

Rebuild

or

replace

the

pump.

c. CoolinA

Systenl.

The

cooling

system

is

thermostatically

controlled

to

8

Chapter

l-General

Engine

Overhaul, Inspection,

and

Repair

regulate

engine

operating

temperature

and

provide

for

a

short

engine

warm-up

period.

(I)

ENGINE

OVERHt.'ATS.

Usually,

engine

over·

heating

is

the

result

of

insuffici

ent

coolant

supply. Check

the

coolant

first.

Make

certain

that

the

cause

of

trouble

is

not

anti-freeze

evaporation

.

(a)

II

the

supply

is

low, check

for

leaks

in

the

cool·

ing

system,

then

make

the

necessary

repairs.

(b)

Check

the

water

pump

belt

for

proper

tension

and

adjust

it

if it is loose.

(c)

Inspect

the

radiator

fins for

obstructions

(bugs,

dirt, etc.).

Clean

it

if

it

is clogged.

(d)

Using a thermometer

in

the

radiator,

check

the

gauge

reading

for

accuracy.

NOTE:

Inaccurate

readings

are

someti~nes

caused

by

insufficient

clearance

between

tire Ifetid c(I!Jting

and

Ihe

temperature

sending

unit

elemen4

Make

repairs

or

replacemenl5

as

neceuary.

(e)

Check

the

thermostat

for

proper

operation

and

heat

range.

If

it

is

defective

or of

the

wrong

heat

range

,

replace

it.

Make

sure

the

thermostat

IS

correctly

installed.

(f)

Check

the

ignition

timing

and

adjust

it if

n

ecessa

ry.

(g)

Check

the

radiator

for

proper

flow. Flush

it if

ne

cessary

.

(h)

Remove

the

water

pump

and che

ck

for a defec-

tive

impeller

or a water

passage

obstruction.

Make

repairs

or

rep

lacements

as

necessary.

(i)

Check

the

cylinder head(s)

for

water

passage

obstructions.

Clean

out

the

passages

or

replace

the

head(s)

if

necessary.

(j)

Check

the

cylinder

block for

water

passage

oJ>.

structions.

Clean

out

the

passages

or

replace

the

block

if

necessary.

(2)

,.;NGINE FAILS

TO

REACH

NORMAL

OPER·

ATING

TEMPERATURE.

Generally,

this

is

caused

by

the

thermostat

sticking

or

being

of

the

wrong

heat

range.

Check

the

thermostat

first.

If

the

engine still

does

not

reach

operating

temperature, check

the

gauge

and

sending

unit

with a thermometer

installed

in

the

radia-

tor.

Replace

any

defective

parts.

2. TUNE·UP

Regular

maintenance

and

inspection

services

are

nec-

essary

for

proper

truck

operation.

In

addition,

to

main-

tain

satisfactory

performance, a periodic

engine

tune-up

should

be

made.

A

reliable

type

of

engine

test

equipment

sho

uld

be

used

to

perform

the

tests

out

lined. in

the

check

ing

pro-

cedures.

As

the

checks

and

tests

ar~

made,

make a visual

inspection

of

the

wiring,

vacuum 'hoses,

cooling

system

hoses,

heater

hoses,

etc.

a.

Minor

Tune·Up.

Perform

the

following

operations

in

the

order

given,

(I)

INSI,,.;CT

U;NITION

WIRES,

BATTERY

CAIJLES, AND

CHECK

THE

CONDITION

OF

THE

BAT1'1:'.-

'R

Y.

In

spect

all

ignition

wires

for

worn

or

damaged

insulation.

Make

sure

the

wires

are

firmly

seated

in

the

distriqutor

cap

and

that

the

terminals

and

the

terminal

soc

kets

are

free

from

corrosion.

In

spect

the

battery

case

for

cracks

and leaks.

Make

a

battery

capacity

test.

If

unsatisfactory,

make a battery

charge

test.

If

the

charge

is low,

recharge

the

battery.

Inspect

the

battery

cable

connections

for

corrosion,

and

clean

them

if

necessary.

Brush

the

cable

connectors

with

grease

to

retard

further

corrosion,

then

tighten

the

con-

nectors

securely.

(2)

TEST

CYLlNDf;R

COMPRf;SSION.

Be

sure

the

batt

ery

is

good.

Operate the

engine

until

normal

oper-

ating

temperature

is

reached.

Turn

the

ignition

switch

off.

Remove

all

spark

plugs.

Set

the

thrott

le in

the

wide

open

position

and

be

sure

the

choke

is

wide

open.

Install a compression

gauge

in

number 1 cylinder.

Crank

the

engine

until

the

gauge

registers a maximum

reading

and

record

the

reading.

Note

the

number

of

compression

strokes

required

to

obtain

this

reading.

Repe

at

the

test

on

each

cylinder,

cranking

the

engi

ne

the

same

number

of

strokes

as

was

required

to

obtain a maximum

reading

on

number

1

cylinder.

A

variation

of ± 10

pounds

from

specified

pressure

is

satisfactory.

However,

the

compression

of

all cylinders

shou

ld

be

uniform

within

10

pounds.

A

reading

of

more

than

10

pounds

above

normal

indi-

cates car

bon

or

lead

deposits

in

the

cylinder.

A

reading

of

more

than

10

pounds

below

normal

ind

i-

cates

leakage

at

the

head

gasket,

rings,

or valves.

A l

ow

even

compression

in

two

adjacent

cylinders

indicates a head

gasket

leak.

This should

be

checked

before condeming

the

rings

or

valves.

T o

determine

whether

the

rin

gs

or

the

valves

are

at

fault,

put a tablespoon

of

heavy oil

on

the

piston,

and

repeat

the

compression test. The oil

will

temporarily

sea

l leakage

past

the

rings.

If

the

same

reading

is

ob-

tained,

the

rings

are

satisfactory,

but

the val

ves

are

l

eaking.

If

the

com

pression

has

increased

10

pounds

or

more

over

the

original

reading,

it

indicates

there

is

leak·

age

past

the

rings.