spark plugs JEEP CJ 1953 Service Manual

'Jeep*
UNIVERSAL SERIES
SERVICE
MANUAL

B
LUBRICATION
AND
PERIODIC SERVICES

Contents
PAR. SUBJECT
PAR.
SUBJECT

GENERAL
.B-l
Chassis
Lubrication
B-7
Engine
Lubrication System B-4, B-6

Special
Lubricants B-2

Fresh
Lubricant.
.B-3

LUBRICATION CHARTS
. Pages 8, 9

SERVICE
MAINTENANCE SCHEDULE.
.B-8
Air
Cleaner
B-2
5,
B-2
6
Air
Filter
—
F.E.E.C.
System Canister
B-2
4

Axle
U-Bolts B-49 Body
Lube
Points: B-65 Hood Hinge Pivot Points B-66

Glove
Compartment Door
Latch
B-6
7
Tailgate Hinges .B-68

Brakes,
Adjust .B-41
Brake
Linings .B-42

Brake
Master Cylinder B-40
Charging
Circuit
B-l9
Clutch
. B-43, B-44
Cooling System—Radiator. B-28, B-29 Differentials
........
.B-50, B-51, B-52, B-53

Distributor
B-14, B-l5

Engine
Oil B-9
Engine
Oil
Filter
B-10, B-ll

Engine
Tune-Up B-20
Exhaust
Emission Control System
B-2
2

Exhaust
Manifold Heat Control Valve. . . .B-l2

Exhaust
System
B-2 3
Fan
Belt . .B-21
Front
Axle U-Joint B-54, B-55

Generator
.B-16
Headlights B-61
Heater Controls B-62
Lights
and Controls B-59 Positive Crankcase Ventilation Valve. . . .B-l3
Shock Absorbers B-48
Spark
Plugs. B-17
Speedometer Cable. .B-60

Spring
Bushings.. . .B-46

Spring
Shackles .B-47
Steering
Gear
B-2 7
B-l. GENERAL
All
'Jeep' Universal vehicles require periodic
lubri­

cation and other maintenance services for normal
vehicle
usage
and application to promote satis­ factory operation and prevent
excessive
wear. Un­
der severe operating or atmospheric conditions
these
services should be performed more
often
than
under normal conditions. It should also be remem­
bered that common short trips and
stop-and-go
driving
are more severe on lubrication
points
than
Starting
Circuit
B-l8

Tie
Rod and Drag
Link
Sockets
.
B-45

Tires
B-64

Transmission
and Transfer Case—
Lubricant
Level
Check B-30

General
B-31

Transfer
Case B-32
Transmission
.B-33

Transmission
and Transfer
Case
—

Lubricant
Change .B-34
General
.B-35

Transfer
Case B-36
Transmission
B-3
7, B-38

Transfer
Case Linkage B-39

Universal
Joints and Slip Joints.
.......
.B-58

Wheel
Bearings..
.........
. . .B-56, B-57
Windshield
Wiper and Washer B-63

LUBRICATION
OF

OPTIONAL EQUIPMENT
B-69
Centrifugal
Governor. .B-71
Pintle Hook .B-70

Powr-Lok
or
Trac-Lok
Differential B-72

PARTS REQUIRING
NO LUBRICATION.
. . .B-73

Alternator
Bearings. B-76
Clutch
Release Bearings.
.............
.B-74
Shock Absorbers B-78
Springs
B-7
7
Starter
Motor Bearings B-75

Water
Pump Bearings B-74

LUBRICATION REQUIREMENTS FOR OFF-HIGHWAY OPERATIONS
B-79

Air
Cleaner B-82

Chassis
Lubrication
B-83

Engine
Oil B-80
Engine
Oil
Filter
B-81
Differentials .B-86
Front
Axle U-Joints. B-84
Transfer
Case and Transmission .B-85
constant
speed
driving on highways, and even more
intensified in extreme cold or hot weather; there­ fore, vehicles driven under
these
conditions must
be lubricated and serviced more
often
than nor­ mally operated vehicles. The specifications of
types
and
amounts of lubricant given in the Lubrication

Chart
and
text
of this section should be closely
followed. The off-highway operation lubrication
notes,
given in the last part of the section, should
be followed when applicable. 7

B
LUBRICATION B-3.
SERVICE
MAINTENANCE
SCHEDULE

Perform
the following operations at the mileage shown. Two thousand miles equals
3,200
km.

SERVICE
MAINTENANCE
SCHEDULE

OPERATION
VEHICLE
^ n>
MILEAGE
IN
THOUSANDS

6 8 10 12 24 30
Check Wheel Nut Torque*
Check
Fluid
Level
in Battery X Check
Fluid
Level
in Brake Master Cylinder0. X
Service
Cooling
System X Service Tires X

Lubricate
Distributor
Cam Lubricator (F4-134) X
Lubricate
Steering Linkage X

Lubricate
Propeller Shaft Universal Joints X

Lubricate
Propeller Shaft
Slip
Joints ; X
Lubricate
Tie Rod and Drag
Link
Sockets................................... X Change Engine
Oil
and
Filter,
and Service Air Cleaner (F4 134 Engine)** X
Change Engine Oil and
Filter,
and Service Air Cleaner (V6-225 Engine)**....
Check Brake Operation and Pedal
Free
Play X Check
Clutch
Pedal
Free
Play. .... X
Check all
V-Belt
Tensions X
Check Exhaust Emission System
(If
so equipped)*** \ X
Service Positive
Crankcase
Vent
Valve
and Breather . .' X
Road Test
Including
a Check of all Instrument
Lights
and Controls X Tune-up Engine
Check Operation of
Manifold
Heat
Control
Valve

Clean
Exterior of Radiator

Align
Headlights • Check Brake
Linings
,
Check Exhaust System for Leaks Replace Canister Air
Filter
(F. E. E. C. System)
Check
Axle
U-Bolt
Torque. Check Lubricaunt
Level
of Front
Axle
Universal Joints
Check Shock Absorber Mountings and Bushings Check Front and
Rear
Spring Bushings

Lubricate
Distributor
(V6-225).
Replace Spark, Plugs
Check Charging and Starting Circuits
Lubricate
Tailgate Latch, Supports and Hinges.

Lubricate
Door and
Hood
Hinge Pivots ;
Lubricate
Glove Compartment Door Latch

Lubricate
Heater Controls •

Lubricate
Windshield
Wiper and Washer Controls
Clean,
Repack and
Adjust
Wheel Bearings
Change Transmission and Transfer Lubricant. .
Replace
Dry-Type
Air Cleaner • Check Lubricant
Level
of
Differential

Lubricate
Transfer
Case
Shift
LeArer
Control
C«se.
. , . . . . . . . .
Continuing
each
2,000 miles

Continuing
each
6,000 miles

Continuing
each
24,000 miles

X
Continuing
each
30,000 miles
•Check after the
first
200 miles [320
km.
J
of operation.
If
wheel or wheels are changed for any
reason,
have
wheel nut torque rechecked after an additional two hundred miles of operation
••Service mileage shown or every 60 days, whichever occurs
first.

•••Maintenance check on emission system must be performed per
information
in this manual. "See text for brakes.

"Nj
^Miles
2,000
6,000
12,000
18,000
24,000
30,000
Kilometers

3,200
9,600
19,200
28,800
38,400 48,000

B-9.
Engine Oil

For
maximum
engine
protection under all driving conditions encountered during the recommended

oil
change intervals, it is necessary to use only

"MS"
certified
sequence-tested
oils. The term
"MS"
must appear on the oil container singly or

in
conjunction with other designations. "MS" des­
ignated oils are heavy-duty detergent oils that are
formulated to withstand all service conditions in
modern powerplants. Engine oils designated only
as
"ML"
and/or
"MM"
are not recommended and should not be used except in an emergency when

"MS"
oil is not available. Certified
sequence-tested

engine
oils are described on their containers by

such
phrases as:
meets,
exceeds,
excels, or has
proven superior in the
test
requirements,
test
sequences, MS Service
tests,
standards, and service

requirements,
of automotive manufacturers, auto­
makers,
or car manufacturers for MS service or
Service
MS.
It
may be necessary to change
engine
oil more
frequently than normally recommended, depending upon the type and quality of oil used, the severity
of operation conditions, if the
engine
is used for
short
periods in cold weather, or if the
engine
is allowed to idle for excessive periods.

Always
drain
the crankcase while the
engine
is hot since
dirt
and contaminants are then more
likely
to be held in suspension and therefore
will

drain
out more completely.
Drain
the crankcase as follows:

a.
Position the
drain
receptacle under the
drain

plug.

b.
Remove the
drain
plug using the correct size

wrench.
Be careful of hot oil.
c.
Carefully
clean the
drain
plug. Inspect and

replace
the gasket, if deteriorated.
d.
When the oil has drained, replace and tighten
the crankcase
drain
plug. 12

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

B
e.
Check
for the presence of
excess
water in the

oil
that might indicate an internal leak from the
cooling system.

f.
Pour oil into the oil filler tube. Replace the oil

filler
cap.

B-10.
Engine Oil
Filter
Service —
Hurricane
F4 Engine

The
engine
oil filter assembly should be replaced at each
2000
miles
[3.200
km.] of normal
engine

use. To remove the filter, use oil filter wrench
C-4065.
To install a new filter, wipe the gasket —
contact surface with
engine
oil, screw on the unit

until
gasket contacts the sealing surface, and then tighten at least one
half
turn
more. DO NOT USE

TOOLS.
Turn
by hand only. When refilling the
engine
crankcase after filter has been changed be

sure
to add one extra quart [1 ltr.] of oil to
fill

filter
and oil passages. Run
engine
to make sure there is no leak at oil filter.

B-l 1.
Engine Oil
Filter
Service — Dauntless V-6 Engine

To
replace the oil filter, use oil filter wrench, Tool

C-4065,
to remove the filter. After the filter has
been removed from the oil pump housing located
on the right front side of the engine, wipe the
housing surface clean and oil the gasket on the base of the new filter to make a
good
seal. Screw
the new filter in position until its gasket contacts
the pump housing surface, then tighten at least
one-half
turn
until filter fits snug.

Note:
Tighten by hand only, do not use a tool to
tighten.

Replace
oil filter each
6000
miles
[9.600
km.] at

engine
oil change.

B-12.
Exhaust
Manifold
Heat
Control
Valve
— Dauntless V-6 Engine

A
thermally-actuated heat control valve is located at
rear
of the right exhaust manifold of the Daunt­

less
V-6 engine.
This
valve has a bimetal thermo­
static spring which holds the valve closed when
the
engine
is cold.

Each
time the vehicle is lubricated place a few drops of penetrating oil on the valve shaft bushings

and
then work the valve by hand making sure that
the lubricant is worked into the bushings.

Note:
If the valve shaft
does
not operate freely
penetrating oil should be used to free the shaft.

B-l 3.
Positive
Crankcase
Ventilation
System

Service
the ventilation system of the
engine
each
multiple of
6000
miles
[9.600
km.] on the odometer
after
initial
2000
miles
[3.200
km.] service. Re­
place the ventilation valve each
12,000
miles
[19.200
km.].

For
information on servicing the positive crankcase
ventilation system on the
Hurricane
F4
engine
and
the Dauntless V-6 engine, refer to the Tune-up Section.

B-l4.
Distributor
— Hurricane F4 Engine

The
distributor shaft is lubricated through an oiler mounted on the side of the housing. Place three or four drops of light
engine
oil in the oiler each
2,000

miles
[3.200
km.]. Also place one drop of light
engine
oil on the wick located on the top of the
shaft, which is made accessible by removing the
rotor
arm. Sparingly apply cam lubricant to the
breaker
arm cam and place a drop of oil on the

breaker
arm pivot.

B-l
5.
Distributor
— Dauntless V-6 Engine

The
distributor has a lubricant reservoir that
car­

ries
sufficient
lubricant
for the life of the distributor.
When
servicing breaker points, place one drop of
light
engine
oil on the wick located on the top of the shaft Also, apply cam lubricant sparingly to
the breaker arm cam, and place a drop of oil on the

breaker
arm pivot.

B-l6.
Generator

On
early production vehicles oilers are provided
at each end of the generator, for lubrication
pur­

pose.
On late production vehicles one oiler is pro­
vided at the
rear
(bushing end) of the generator for lubrication purpose. Place two to four drops of
light
engine
oil in each oiler every
2,000
miles
[3.200
km.].

B-l
7. Spark Plugs

Replace
spark
plugs. Refer to Section C.

B-18.
Starting
Circuit

Check
the starting
circuit.
Refer to Section H.

B-l
9. Charging
Circuit

Check
the charging
circuit.
Refer to Section H.

B-20.
Engine Tune-Up

Refer
to Section C of this manual.

B-21.
Adjust
Fan
Belt

Refer
to Section C.

B-22.
Exhaust Emission
Control
System or
Controlled
Combustion System

•
Refer to the appropriate section in this manual.

B-23.
Exhaust System

Check
the exhaust system for leaks. Refer to Section F.

B-24.
Fuel Evaporative Emission
Control
Canister Air
Filter

The
only service required for the
F.E.E.C.
system
is cleaning the air cleaner filter mounted at the
bottom
of the canister. The filter requires replace­
ment at
12,000
mile intervals. Refer to Section

E,
Par. E-9 for service procedure.

B-25.
Oil Bath Air Cleaner
Some 'Jeep' Universal vehicles are equipped with

an
oil bath type air cleaner.
This
type air cleaner
thoroughly removes all dust from the air before it enters the carburetor, if it is properly serviced.

When
the vehicle is operated under normal condi­
tions the air cleaner must be serviced at regular

intervals
as care of the air cleaner is extremely 13

Jeep*
UNIVERSAL SERIES SERVICE
MANUAL

c
TUNE-UP

Contents

SUBJECT
PAR.

GENERAL
C-l

TUNE-UP
.C-2
Air
Cleaner
C-21

Battery
. C-3
Carburetor
Adjustments
C-2 5

Coil
C-20
Crankcase
Ventilation C-6

Cylinder
Compression C-9

Cylinder
Head(s) .C-5

Dash
Pot Adjustments .C-26

Distributor
Service C-10
thru
C-13

Distributor
Resistance Test C-l6

Fan
Belt
C-2 7
Fuel
Lines
and Screens
C-2
2

C-l.
GENERAL
An
engine tune-up should be performed for all
Jeep Vehicles each 6000 miles [9.600 km.] or at the end of each 250 hours off-the-road operation,
to ensure best possible performance at all times.
The
tune-up should follow the sequence given in
this section.
Because of federal laws limiting exhaust emissions,

it
is even more important that the engine tune-up is
done
accurately, using the specifications listed
on the tune-up sticker found in each engine com­

partment.

Note;
To ensure proper operation and effectiveness
of the exhaust emission control system, and to
comply with
Federal
and State requirements, a
recheck
of ignition timing, idle speed and idle mix­

ture
and necessary adjustments must be performed
after the first
2,000
miles [3.200 km.] of vehicle
operation.

A
minor engine tune-up should be performed every
6,000
miles [9.600 km.] or at the end of 250 hours
of off-the-road use.
Major
engine tune-up should
be performed every 12,000 miles [19.300 km.].

The
parts of units which affect power and perform­
ance may be divided into three groups:
(1) Units affecting compression
(2) Units affecting ignition
(3) Units affecting carburetion

The
tune-up procedure should cover
these
groups
in
the order given. While the items affecting com­
pression and ignition may be handled according
to personal preference, correction of items in the
carburetion
group should not be attempted until

all
items affecting compression and ignition have
been satisfactorily corrected.

Note:
To make sure hydro-carbon and carbon
monoxide emissions
will
be within limits, it is very

impotrant
that the adjustments be followed exactly
as listed on the sticker found in each engine compartment.
SUBJECT
PAR.

Fuel
Pump . . C-23

Heat
Control
Valve C-7

Ignition
Cables C-19

Ignition
Timing
. C-14

Ignition
Wires C-l8

Manifold
C-5

Manifold
Vacuum C-24

Point
Dwell C-17

Primary
Circuit
Tests
.................
C-15
Spark
Plugs C-4

Tappets
C-8

ROAD TEST C-2
8

SERVICE
DIAGNOSIS
. : C-29

TUNE-UP SPECIFICATIONS..
C-30

Minor
engine tune-up consists of the following.
Inspect
and correct as required:
Battery
cables and connections.
Alternator
and regulator wiring.

Primary
— Secondary wiring, distributor cap.

Cylinder
head torque.

Contact
point dwell.

Vacuum
and centrifugal advance.

Ignition
timing.
Spark
plugs for correct air gap.

Adjust
idle speed and idle air mixture.

Adjust
all drive belt tensions.
Clean
carburetor air cleaner.

Lubricate
exhaust manifold damper.

Major
engine tune-up includes the following.
Inspect
and correct as required:
Battery
condition and charging
circuit.
Clean,
lubricate
and tighten battery cable connec­
tions.

Ingition
system.
Spark
plugs; replace if necessary or clean and gap.

Compression
check.

Primary—Secondary
wiring, distributor cap.

Replace
contact points and condenser.

Lubricate
distributor cam with cam grease.
Adjust
contact points.

Check
vacuum and centrifugal advance. Set ignition timing.

Torque
cylinder head.
Adjust
idle speed and idle air mixture.

Replace
fuel filter element (every 12,000 miles [19.300
km.]).

Adjust
all drive belt tensions.

IMPORTANT: SPECIFICATIONS
FOR EN-

GINE
RPM.
DISTRIBUTOR POINT DWELL,
AND IGNITION TIMING GIVEN
IN
TUNE- UP SECTION
C
REFER
TO
VEHICLES
WITH
AND WITHOUT EXHAUST EMISSION CON­

TROL
SYSTEMS.

FOR
VEHICLES
EQUIPPED WITH EXHAUST
EMISSION CONTROL SYSTEMS ALSO
REFER
TO
SECTION
Fl (F4-134
ENGINE)
AND
F2 (V6-225
ENGINE).
19

c

TUNE-UP
C-2.
TUNE-UP SEQUENCE

The
following
Pars.
C-3 through
C-2
7
give the
sequence and describe the services to be performed
when tuning the engine.

C-3.
Clean
and
Check
Battery
Inspect
battery and cables. If the battery is not
satisfactory, install a fully-charged battery to allow
completion of the tune-up.
Note: If the battery fails any of the following tests,
remember that the cause may be other electrical
trouble, and not necessarily only a defective battery.
Refer
to Section H for electrical troubleshooting

and
tests.

a.
Check
the specific gravity of the eletrolyte in
each cell of the battery. A hydrometer reading of 1.260 indicates that the battery is fully charged.

If
the reading is 1.225 or below, the battery
needs

recharging.
If one or more cells is 25 "points" (.025)

or
more lower than the other cells, this indicates
that the cell is shorted, the cell is about to
fail,
or
there is a
crack
in the battery partition in the case.
Unless the battery is repaired or replaced, battery trouble
will
soon be experienced.

b.
Check
the electrolyte level in each cell, add

distilled
water to maintain the solution %" [9.5
mm.] above the plates. Avoid overfilling. Replace
the filler caps and tighten securely. It is important
to keep the electrolyte level above the plates at
all
times because plates that are exposed for any
length of time
will
be seriously damaged.

c.
Check
the wing nuts on the hold-down frame
for tightness. Tighten them only with finger pres­

sure,
never with pliers or a wrench. Excessive pres­

sure
could damage the battery case.

d.
Clean
the battery terminals and cable connec-
FIG.
C-l—FRAME
GROUND
STRAP
—

HURRICANE
F4
1—
Right
Front
Engine Mount

2—
Frame
Ground
Strap
DAUNTLESS
V-6
tors.
Prepare a strong solution of baking soda and

water
and brush it around the terminals to remove

any
corrosion that is present. The cell caps must
be tight and their vents sealed to prevent cleaning
solution entering the cells. After cleaning install
cable connectors on terminals and coat the ter­
minals
and connectors with heavy grease.
e. Inspect the battery cables and replace if badly

corroded
or frayed.
Check
tightness of terminal
screws to ensure
good
electrical connections.
Check

the tightness of the negative ground cable connec­ tion at the engine to ensure a
good
ground con­ nection.

f.
Load
test
the battery. Connect a voltmeter across the battery. Run the starting motor for 15 seconds.
If
the voltage
does
not drop below 10 volts on a 12 volt battery the battery is satisfactory. If the
voltage falls below
these
values, yet the specific
gravity
is above
1.225,
the condition of the battery
is questionable.

g.
Make sure the engine to frame ground strap or
cable connections are tight. If
these
connections
are
loose,
corroded or dirty,
hard
starting or failure
of the vehicle electrical system may result. Refer
to
Fig.
C-l
for location of the
Hurricane
F4 engine
to frame ground strap and its connections. Refer to Fig. C-2 for location of the Dauntless V-6 en­ gine to frame ground cable.

C-4.
Clean and
Adjust
Spark Plugs
Clean,
inspect, and gap
spark
plugs. Do not install

spark
plugs until completion of compression tests.

a.
Use a
Spark
Cable
and Installing
Plier
Tool,

W-2
74,
to remove the leads from the
spark
plugs.

Caution:
Pulling on the cables to remove them

from
the
spark
plugs can cause internal breaks in
the leads that
will
cause ignition failure.

b.
Using a
spark
plug wrench, loosen each
spark

plug one or two turns to break
loose
any carbon
deposits on the plug base. 20

'Jeep'
UNIVERSAL SERIES SERVICE
MANUAL

FIG.
C-3—SETTING SPARK PLUG
GAP
1—Wire
Gauge 2—Spark Plug
c.
Blow out all carbon and
dirt
from each
spark

plug hole with compressed air. If compressed air is
not available, start the engine and accelerate to 1000 rpm. to blow out the carbon and
dirt.
Stop
the engine.

d.
Remove the plugs carefully with a
spark
plug

wrench.

e. Inspect the plugs for serviceability. Especially
check
for burned and eroded electrodes, blistering
of porcelain at the firing tip, cracked porcelain, or

black
deposits and fouling. These conditions in­
dicate that the plugs have not been operating at
the correct temperature. Replace bad or worn plugs

in
sets.
f. Measure the electrode gap of each new or exist­
ing plug with a wire
gauge
as shown in Fig. C-3.

Adjust
each electrode gap to the specific gap by
bending the outer electrode mounted in the plug
shell.

g.
Clean
the plugs on a sand blast cleaner. Avoid
too much abrasive blast as it
will
erode the in­
sulator.
Clean
the threads with a wire
brush.

Deposits
will
retard
heat flow to the cylinder head.

h.
Clean
the electrode surfaces with a small flat
file. Dress the electrodes to secure flat parallel surfaces on both the center and side electrode.

i.
Champion J-8 are the replacement
spark
plugs
recommended for the F4-134 engine. Adjust elec­
trode gap to .030" [0,762 mm.] and should be
torqued to 25 to 33 lb-ft. [3,5 a 4,6 kg-m.].

j.
For the V6-225 engine, AC 44S or Champion

UJ12Y
spark
plugs are the replacement
spark

plugs recommended. The
spark
plugs should be gapped to .035" [0,889 mm.] and should be
torqued to 25 to 33 lb-ft. [3,5 a 4,6 kg-m.].
C-5. Torque Cylinder
Head(s)
and
Manifold
a.
Hurricane
F4 Engine.

Torque
the cylinder head bolts with a torque

wrench
to 60 to 70 lb-ft [8,3 a 9,7 kg-m.]. Follow
the sequence shown in Fig. C-4. Do not overlook
tightening the cylinder head bolt, No. 5, in the

intake
manifold directly under the carburetor
opening. 10102

FIG.
C-4—HURRICANE
F4
ENGINE CYLINDER HEAD BOLT TIGHTENING SEQUENCE
Torque
all manifold attaching nuts evenly to 29
to 33 lb-ft. [4,0 a 4,6 kg-m.].
b.
Dauntless V-6 Engine.

Torque
cylinder head bolts 65 to 85 lb-ft. [9,0 a 11,8 kg-m.]. Follow the sequence shown in Fig.

C-5.
Torque all intake manifold bolts 45 to 55 lb-ft. [6,2 a 7,6 kg-m.]. Torque all exhaust manifold bolts
15 to 20 lb-ft. [2,1 a 2,8 kg-m.]. Refer to Fig. Dl-
for tightening sequence. 14203

FIG.
C-5—DAUNTLESS
V-6
ENGINE CYLINDER HEAD BOLT TIGHTENING SEQUENCE C-6.
Service
Crankcase
Ventilating System

•
Refer to Fig. C-6 and C-7.
Positive crankcase ventilation is accomplished by

utilizing
the vacuum created in the intake mani­
fold to draw clean air through the crankcase and
valve chamber. A valve, in the vacuum line to the

intake
manifold, varies the air flow through the

crankcase
to
meet
changing conditions at all engine

speeds
and loads. The system
will
work effectively as long as all component parts are clean and free

from
sludge and carbon. Improper operation of the ventilating system can contribute to rough
idling,
power loss, and the formation of sludge and

varnish
in the engine.

The
system also prevents crankcase vapors from
entering the atmosphere. Engine vapors are drawn
into the carburetor through the ventilation valve
and
burned with the normal fuel mixture. 21

c

TUNE-UP

14011

FIG.
C-8—POSITIVE CRANKCASE VENTILATION VALVE
vacuum
hose
and insert a stiff wire into the valve
body and observe whether or not the plunger can be readily moved (Fig. C-8). The valve may be
cleaned, by soaking in a reliable carburetor clean­
ing solution and drying with low pressure dry air.
b.
Hurricane
F4 Engine.

Ventilation
of the
Hurricane
F4
engine
is accom­
plished in the same manner as the Dauntless V-6

engine
described above, the differences being that clean air enters the crankcase through a
hose
con­ nected
between
the top cover of the air cleaner and
the oil filler tube of the engine. The ventilation valve is screwed to a pipe fitting mounted in the
center of the intake manifold
between
number two

and
three cylinder inlet. A
hose
connects the venti­
lation valve to a vapor
dome
on the rocker arm
cover. Service procedures are the same as
those

used on the Dauntless V-6 engine. The valve may be checked for vacuum
pull
by removing the
hose

from
the valve while running the
engine
at fast idle speed and placing a finger on the valve opening to
check the vacuum. (Refer to Fig. C-9).

C-7.
Service
Manifold
Heat
Control
Valve
The
Dauntless V-6
engine
is equipped with a mani­fold heat control valve (Fig. F-6). Test the valve
for free operation. Place a few drops of penetrating

oil
at each end of the shaft where it passes through
the manifold.
Then
move
the valve up and down

a
few times to work the oil into the bushing. When
the
engine
is cold, the valve should be in the closed
position to ensure a fast warm-up of the intake
manifold for better fuel vaporization. When the
valve is closed, the counterweight is in its counter­ clockwise position. As the
engine
warms the coun­
terweight slowly rotates clockwise until the valve is fully open.

C-8.
Check
Valve
Tappet
Clearance
a.
Hurricane
F4 Engine.

With
the
engine
cold, check and adjust the intake
valve to .018"
[0,460
mm.] clearance and the ex­
haust valves to .016" [0,406 mm.] clearance. The
intake valves are adjusted by removing the rocker

arm
cover mounted on the cylinder head.
Turn
the
engine
over until No. 1 cylinder piston is on top
dead center on its compression stroke, then using a
feeler
gauge
check the clearance
between
the valve stem and the toe of the rocker arm. If clearance is

less
or greater than .018"
[0,460
mm.] the valve
must be adjusted by turning the rocker arm nut
clockwise to decrease and counterclockwise to in­ crease the clearance. When No. 1 cylinder intake
valve has been properly set use the same proce­
dures to check and reset, if necessary, the remaining
three cylinder valves. The exhaust valves are ad­ justed by removing the tappet cover located on
the right side of the engine. Place the cylinder to
be adjusted on top dead center (compression stroke) and check the clearance
between
the valve stem and tappet screw with a feeler
gauge.
If the
clearance is
less
or greater than .016" [0,406 mm.]
the valve must be adjusted by loosening the tappet
screw locknut and turning the screw until the proper clearance is obtained, then tighten the lock-
nut.

Note:
Always recheck the valve clearance after
tightening the locknut.
b. Dauntless V-6 Engine.

The
valve tappet clearance of the Dauntless V-6

engine
needs
no adjustment as the lifters are

hydraulic
and require no lash adjustment at time
of assembly or while in service.

C-9.
Check
Engine
Cylinder
Compression
a.
Hurricane
F4 Engine.

To
take the compression readings of the
engine
cylinders
remove all the
spark
plugs and disconnect
the high tension wire from the coil.
With
the throttle and choke open
turn
the
engine
with the

starter
motor while firmly holding the compression
gauge
in the
spark
plug port of the cylinder to be
checked. Allow at least four compression strokes
when checking each cylinder and record the first
and
fourth stroke reading of the
gauge.

When
pressure quickly
comes
up to specified pres­

sure
and is uniform
between
all cylinders within 10 psi. [0,7 kg-cm2] it indicates that the
engine
is
operating normally with satisfactory seating of

rings,
valves, valve timing, etc.
When
pressure is low on the first stroke and builds
up to
less
than specified pressure it indicates com­
pression leakage usually attributable to rings or
valves. To determine which is responsible, pour
Vz
oz. [15 cm3] of tune-up oil into each cylinder.

Allow
a few minutes for the oil to leak down past
the rings and then again
test
compression. If com­
pression pressures improve over the first
test,
the trouble is probably worn piston rings and bores. If
compression pressures do not improve, the trouble
is probably caused by improper valve seating. If
this condition is noticed on only two cylinders that
are adjacent, it indicates that there is a possible gasket leak
between
these
cylinders. If inspection
of the
spark
plugs from
these
cylinders disclosed
fouling or surface cracking of electrodes, gasket leakage is probable.

When
pressure is higher than normal it indicates
that carbon
deposits
in the combustion chamber have reduced the side of the chamber enough to
give
the
effect
of a raised compression ratio.
This

will
usually cause a pinging sound in the
engine
when under load that cannot be satisfactorily cor­rected by timing. The carbon must be cleaned out
of the
engine
cylinders to correct this trouble.

Reinstall
the
spark
plugs. Torque with a wrench
to proper setting.

Advise
the vehicle owner if compression is not satisfactory. 24

c

TUNE-UP
meter during this
test
Connect the red lead
tc*
dis­

tributor
primary
lead at the coil as shown in Fig.
C-21.
Connect black lead to the ground.
Turn

ignition switch on; with
engine
stopped, observe
dwell
meter. If the meter reads zero,
crank
the

engine
a fraction of a revolution to
close
the

breaker
points.

Distributor
resistance is normal, if dwell meter
pointer is within range of
black
bar. Distributor resistance is high, if
dwell
meter pointer is not

within
the black bar.
Remove test lead from
distri­
butor terminal of coil and
connect
to
each
of the
following points to determine
where
the excessive resistance is:

Distributor
primary
terminal

Distributor
primary
terminal in the distributor

Breaker
point bracket
Ground
side of points

Distributor
housing

Where
a noticeable change occurs in the meter
reading
in
these
steps, make the necessary correc­
tion and repeat the
test.

C-l 7. Distributor
Point
Dwell

Using
a dwell tester, connect red
lead
to the
distri­

butor terminal at coil. Connect black lead to
ground.
Set selector switch to the number of
cylin­

ders in the
engine
being tested. Operate
engine
speed at specified rpm. and
note
readings. Cam

dwell
angle must be 30° for the Dauntless V-6
Delco equipped engine, 29° ±: 3° Prestolite equipped
engine
and 42° for the
Hurricane
F4 engine. If the dwell reading is not to specifications,
trouble could be improper point spacing, point

rubbing,
defective block or breaker arm, or mis­
aligned and worn distributor cam.
Adjust
dwell
as shown in Fig. C-14 for the Delco equipped
Dauntless V-6 engine. For cam dwell adjustment
of the Prestolite equipped V6 and
Hurricane
F4 engine, refer to Par. C-10,
step
a.

Dwell
variation is determined by noting any
dwell
change as the
engine
is operated at different
speeds.

Excessive
variation indicates a change in point opening that can result from shaft or bushing wear,

or
from the distributor plate shifting because of

wear
or
looseness.

Measure
dwell variation at idle speed, using same

test
hookup for checking dwell. Increase speed to 1750 rpm.;
note
dwell reading.
Then
slowly reduce
speed to idle while observing dwell meter. Dwell

variation
should not exceed 3°. If dwell variation
exceeds
3°
between
idle speed and 1750 rpm.,
probable wear in the distributor shaft, bushings, or

breaker
plate is indicated. Distributor should then be checked more thoroughly.

C-l8. Check Ignition Wires
and
Connections

Examine
and clean the insulation on all ignition

wires
and check all connections. Wires should be
firm,
flexible, and free from roughness and minute
cracks.
Bend wires to check for brittle,
cracked,
or

loose
insulation. Since defective insulation
will
per­

mit
crossfiring or missing of the engine, defective

wires
should be replaced.

C-l9. Test Ignition
Cables

To
remove cables from
spark
plugs, use
Spark
Plug
Cable
Remover
Tool
W-274.
Twist
the
boot

slightly to break the seal and, grasping the rubber
protector
boot,
lift straight up with a steady even

pull.
Do not grasp the cable and
jerk
the cable off; this
will
damage the cables. Do not use a probe
on
these
wires; puncturing them may cause a
separation in the conductor. To remove ignition cables from the distributor cap or coil tower,
loosen

the nipple first, then grasp the upper part of the nipple and the cable and gently
pull
straight up.

Test
the cable with an ohmmeter. Resistance value

per
foot
is
3000-7000
ohms. The ignition cables
can
be checked for
circuit
continuity by removing
the cable from the
spark
plug and holding the cable
end Vi" [6,35 mm.] from the engine. A strong

spark
indicates
good
conductor continuity.

When
connecting the cable to the
spark
plug, be
certain
a
good
connection is made and that the
protector
boot
fits tight on the
spark
plug. A
partially
seated cable creates an additional gap in
the
circuit
and the resulting
spark
jump
will
cause

terminal
corrosion and cable damage.

C-20. Coil

When
an ignition coil is suspected of being defec­ tive, it should be checked on the car. A coil may

break
down after it has reached operating tempera­
ture.
It is important that the coil be at operating
temperature when
tests
are made.

Note:
The ignition coil and ballast resistor for the

V-6
engine
must be of the same manufacturer.
Ballast
resistors and ignition coils of one manufac­

turer
are interchangeable with both units of the
other.
C-21.
Service Air
Cleaner

Refer
to Par.
B-2 2
for the correct service of the

air
cleaner.

C-22.
Check Fuel Lines and
Screens

Check
all fuel line connections to guard against
leakage.
Check
fuel pump filter F4
engine
and
fuel
line filter V-6 engine. Replace fuel filter if
necessary.

C-23. Check Fuel Pump a.
Fuel
pump pressure is important, for low pres­

sure
will
seriously affect
engine
operation and high

pressure
will
cause excessive fuel consumption and
possibly flood the carburetor. Should there be any doubt of normal operation, check the pressure with
a
gauge
as shown in Fig.
C-2 2.
The minimum and

maximum
allowable pressures are 2% to 3% lbs. [0,176 a
0,264
kg-cm2], for the
Hurricane
F4 en­
gine.
Fuel
pump pressure at carburetor (inlet) on
the Dauntless V6-225
engine
should be 3% lbs.
[0,264
kg-cm2] minimum at specified
R.P.M.
idle

with
the vapor
return
hose
squeezed off.
With
the

vapor
return
hose
open pump pressure should be
2
V2
lbs. [0,176 kg-cm2] minimum.

b.
Test for volume, as a pump may build up suffi­
cient pressure but
fail
to produce sufficient volume.
Turn
down the carburetor fuel line fitting on the
pump and with the tank line connected, pump out
30

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

C

FIG.
C-22—-CHECKING
FUEL
PUMP
PRESSURE
—
DAUNTLESS
V-6
ENGINE a
couple of strokes to be sure the pump is primed.

Using
a half-pint
bottle
or similar measure, pump
Vi
pint [0,24 It] of fuel by cranking the
engine

with
the starter motor. Count the strokes neces­
sary
to
fill
the measure. If more than 20 strokes

are
required, the fuel pump is inefficient, the tank
line is leaking air, or the fuel supply is restricted.

Check
fuel filter in the fuel tank if line is restricted.

C-24.
Check Manifold Vacuum

To
check the intake manifold vacuum on the
Hurri­

cane F4 engine, remove the ventilation valve and

L
fitting from the manifold and install special adapter. On the Dauntless V-6
engine
remove the
pipe plug located in the right
rear
of the intake
FIG.
C-23—CHECKING MANIFOLD VACUUM
—

HURRICANE
F4
ENGINE
manifold and install special adapter. Connect the

vacuum
gauge
tube to the special adapter as shown

in
Fig. C-23 for the
Hurricane
F4 engine.

Start
the engine. Connect a Tachometer
Tool,

C-3896,
from the distributor
primary
terminal to ground and set the
engine
speed at the specified

rpm.
given in Par. C-30. Observe the vacuum
read­

ing and interpret as follows:

a.
A steady reading from 18" to 20" [457 a 508
mm.] of mercury is a normal reading, indicating
that valve and
spark
timing, valve seating, and
piston ring sealing are all satisfactory.
b. A steady but below normal reading indicates

a
condition common to all cylinders such as a

leak
at the carburetor gasket, late ignition or valve
timing, or uniform piston ring and bore wear.

c.
A slowly fluctuating or drifting reading in­ dicates that the carburetor idle mixture is incorrect

Look
for the cause in the fuel system.

d.
A rhythmic pulsating reading is caused by a
condition affecting one or more cylinders, but not

all,
and indicates leaky valve, gasket blowby, re­
stricted intake port, or an electrical miss.
e. An intermittent pulsating reading is caused by

an
occasional malfunction, such as a sticking valve
(all
valves may be
erratic
in operation if the valve
springs are weak), electrical miss caused by insuffi­
cient distributor point tension or low coil
voltage

coupled with inconsistent
spark
plug
gaps
or fouled
plugs, or
dirt
in the fuel system finding its way into
passages of
critical
size or valve
seats
in the
car­

buretor.

f.
A normal reading that quickly falls off (with

engine
running at
2000
rpm.) indicates exhaust
back
pressure caused by a restriction in the exhaust
system.

g.
Make indicated corrections to bring vacuum to 18" to 20" [457 a 508 mm.] of mercury normal

reading.

C-25.
Carburetor Adjustments

•
Refer to Fig. C-24, C-25 and C-26.

Carburetor
adjustments should not be attempted

until
it is known that
engine
ignition and com­
pression are in
good
order. Any attempt to adjust

or
alter the carburetor to compensate for faulty conditions elsewhere
will
result in reduced econ­
omy and overall performance.

Caution:
If an
engine
is idling too slow or rough,
this may be caused by a
clogged
ventilator valve

or
hose;
therefore, never adjust the carburetor idle
without first checking the crankcase ventilator
check valve and
hose.

The
air cleaner must be left in place while making
idle speed and mixture adjustments. All lights and accessories, must be turned off. The positive
crank­

case ventilator system should also be in
good
oper­
ating condition when making carburetor adjust­ ments.
Either
of
these
items noticeably affects the

air
fuel ratio at idle.

•
Hurricane
F4 Engine.
Note:
The idle mixture adjustment procedure for
the late model
YF-4941S
and
YF-6115S
Carter

31

TUNE-UP

C-29.
SERVICE
DIAGNOSIS

POOR
FUEL ECONOMY Ignition Timing Slow or Spark Advance Stuck

Carburetor
Float High
Accelerator Pump Not Properly Adjusted High Fuel Pump Pressure

Fuel
Leakage

Leaky
Fuel Pump Diaphragm Loose Engine Mounting Causing High Fuel Level in Carburetor

Low
Compression
Valves Sticking
Spark
Plugs Bad

Spark
Plug Cables Bad
Weak
Coil
or Condenser Improper Valve Tappet Clearance

Carburetor
Air Cleaner Dirty
High Oil Level in Air Cleaner Dragging Brakes

Front
Wheels Out of Alignment

Tires
Improperly Inflated Inaccurate Odometer

Faulty
Fuel Tank Cap
Clogged
Muffler or Bent Exhaust Pipe Sticking Exhaust Manifold Valve

LACK
OF POWER
Low
Compression Ignition System (Timing Late)
Improper Functioning Carburetor
or Fuel Pump

Fuel
Lines
Clogged

Air
Cleaner Restricted Engine Temperature High Improper Tappet Clearance
Sticking Valves
Valve Timing Late

Leaky
Gaskets
Muffler
Clogged

Bent Exhaust Pipe Sticking Exhaust Manifold Valve —
Dauntless V-6 Engine

LOW
COMPRESSION
Leaky
Valves Poor Piston Ring Seal Sticking Valves
Valve Spring Weak or Broken
Cylinder
Scored or Worn
Tappet Clearance Incorrect Piston Clearance too Large

Leaky
Cylinder Head Gasket

BURNED
VALVES AND SEATS Sticking Valves or too Loose in Guides
Improper Timing
Excessive Carbon Around Valve Head and Seat Overheating
Valve Spring Weak or Broken
Valve Tappet Sticking
Valve Tappet Clearance Incorrect
Clogged
Exhaust System

Defective
Valve
Lifter
— Hydraulic
VALVES
STICKING
Warped Valve Improper Tappet Clearance Carbonized or Scored Valve
Stems

Insufficient Clearance Valve Stem to Guide
Weak or Broken Valve Spring Valve Spring Cocked Contaminated Oil

OVERHEATING
Inoperative Cooling System
Theromstat Inoperative Improper Ignition Timing
Improper Valve Timing
Excessive Carbon Accumulation
Fan
Belt too Loose

Clogged
Muffler or Bent Exhaust Pipe
Oil
System Failure Scored or Leaky Piston Rings
Sticking Exhaust Manifold Valve — Dauntless V-6 Engine

POPPING-SPITTING-DETONATION
Improper Ignition Improper Carburetion
Excessive Carbon
Deposit
in
Combustion Chambers
Poor Valve Seating Sticking Valves
Broken Valve Spring Tappets Adjusted too Close
Spark
Plug Electrodes Burned
Water or Dirt in Fuel
Clogged
Lines Improper Valve Timing

Clogged
Fuel Filter Sticking Exhaust Manifold Valve —
Dauntless V-6 Engine

EXCESSIVE
OIL CONSUMPTION Piston Rings Stuck in Grooves, Worn or Broken Piston Rings Improperly Fitted or Weak Piston Ring Oil Return
Holes
Clogged

Excessive Clearance, Main and
Connecting Rod Bearings

Oil
Leaks at Gaskets or Oil Seals
Excessive Clearance, Valve Stem
to Valve Guide (Intake)

Cylinder
Bores Scored, Out-of-
Round or Tapered
Too Much Clearance, Piston to Cylinder Bore
Misaligned Connecting Rods
High Road
Speeds
or Temperature
Crankcase
Ventilator Not Operating

BEARING
FAILURE
Crankshaft
Bearing Journal Out-of-Round

Crankshaft
Bearing Journal Rough

Lack
of Oil
Oil
Leakage

Dirty
Oil

Low
Oil Pressure or Oil Pump Failure

Drilled
Passages
in Crankcase or Crankshaft
Clogged

Oil
Screen Dirty
Connecting Rod Bent 34