ECU JEEP CJ 1953 Service Manual

'Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL

A
GENERAL
DHTfl

Contents

SUBJECT
PAR.

General
A-l

Vehicle
Description .A-2

Vehicle
Identification A-3
Identification
Number Location A-4
Serial
Number Location A-5

Engine
Code Number A-6

Plate-And-Trim
Option Plate A-7

General
Specifications A-8

A-1.
GENERAL
This
manual is provided for the guidance of all
automotive service men, vehicle owners, and service salesmen who
repair,
maintain, or adjust
the 'Jeep' Universal Series vehicles. The informa­tion herein was prepared from the service man's
viewpoint to
give
him the accurate and concise
data
he may need to service the entire vehicle.

The
information is not elementary as it is intended
for automotive service men who are familiar with
automotive construction and repair in general. It is not intended, nor would it be possible in such

limited
space, to cover every possible repair that he may encounter. All specifications are in accord

with
Engineering Specifications and should be

adhered
to in all work on the vehicle.
The
manual sections follow logical division into

major
components of the vehicles. The first
page

of each section has a detailed index of the
contents
of that section. Subject matter covers all models

included
in this manual unless an exception for a

particular
model is specifically mentioned.
Specifications and components covered were for

standard
production models of 'Jeep' vehicles
current
at the time the manual was approved for

printing.
'Jeep' Corporation reserves the right to
discontinue models at any time or change specifi­
cations or design of any of its models without
notice and without
incurring
any obligation.

A-2.
Vehicle Description

This
manual covers all standard production 'Jeep'

Universal
models currently being produced at the time this manual was approved for publication.

Significant
changes made in each model since it
was first produced are included in the manual.
A
description of each model follows.
General

specifications for each model are listed in Par. A-8. Detailed specifications covering major vehicle units

are
listed at the end of each section of the manual.
CJ-3B
—
This
is a 4-wheel-drive 'Jeep' Universal
model, equipped with the four-cylinder

Hurricane
F4-134 engine. Wheelbase is 80".

CJ-5

CJ-5A
— These are 4-wheel-drive 'Jeep' Universal models, equipped with either the Daunt­

less
V-6 engine, or the four-cylinder

Hurricane
F4-134 engine. Wheelbase is 81".

CJ-6
CJ-6A
— These are 4-wheel-drive 'Jeep' Universal models, equipped with either the Daunt­
less
V-6 engine, or the four-cylinder

Hurricane
F4-134 engine. Wheelbase is 101".

DJ-5
DJ-6
— These are 2-wheel-drive 'Jeep' Universal models, equipped with the four-cylinder

Hurricane
F4-134 engine. DJ-5 wheel- base is 81". DJ-6 wheelbase is 101".

A-3.
Vehicle Identification
Each
'Jeep' vehicle model series has one or more

serial
number prefixes to identify it. Complete
identification of a specific vehicle requires the

prefix
plus the
serial
number.
Serial
numbers are
consecutive for each prefix grouping. Prefix infor­
mation following
will
identify the 'Jeep' models
shown by
serial
number prefix from model inception to date.-.
••
' . -

Note:
Vehicles with a
serial
number prefix of five
(5) or more digits that have an S, 5, or 7 as the last
digit are equipped with
Exhaust
Emission
Control.

A
number 1 in the sixth (6th) digit within a seven (7) digit vehicle
serial
number prefix indicates

Left
Hand
Drive;
a 2 indicates Right
Hand
Drive;
a
3 indicates
Left
Hand
Drive
California
Exhaust

Emission
Control
Engine;
a 4 indicates Right
Hand
Drive
California
Exhaust
Emission
Control
Engine.
3

LUBRICATION

vital
to the life of the
engine.
When the vehicle
is operated under abnormal conditions, (for ex­
ample when driven on secondary roads or through
fields) then service of the air cleaner must be more frequent

Note:
Under extreme continually dusty and dirty
conditions where the vehicle operates in clouds of dust and
dirt,
service the air cleaner daily.

a.
To service the air cleaner on vehicles equipped
with the
Hurricane
F4
engine
(Fig. B-5) unscrew
the eye
bolt
on the oil cup clamp and remove the

oil
cup from the cleaner body. Remove the oil from the cup and scrape all
dirt
from the inside, wash cup clean using a cleaning solution if neces­

sary.
In summer
refill
the oil cup with IV2 pints [0,6 ltrs.] of
SAE-40
or 50 grade
engine
oil. In
winter
refill
using grade
SAE-20
engine
oil. For
servicing the air cleaner
body
(less
oil cup),
loosen

hose
clamp and remove
hose
from the cleaner. Detach breather
hose
from the fitting on the cleaner. Remove the two wing screws and lift the
cleaner from the vehicle. Agitate the cleaner
body

thoroughly in cleaning solution to clean the filtering

element.
Dry
element
with low pressure com­ pressed air. Reinstall the cleaner
body
and replace
the oil cup. Service the air cleaner every
2000
miles
[3.200
km.].
b. To service the oil bath air cleaner on vehicle
equipped with the Dauntless V-6
engine
(Fig. B-6),

first
remove the air cleaner from the carburetor
by unscrewing the wing nut. Remove the oil cup
FIG.
B-5—OIL
BATH AIR
CLEANER
-
HURRICANE F4 ENGINE 1—
Horn
7—Clamp
2—
Flexible
Connector
8—Oil
Cup
3—
Hon
Clamp
9—Clamp

A—Carburetor
Vent Tube 10—Hose 5— Body 11—Clamp
6—
Screw
and
Lock
Washer 13—Gasket
FIG.

B-6—OIL BATH AIR
CLEANER
-
DAUNTLESS V-6 ENGINE

1—WinB
Nut
2—
Cover

3—
Rubber
Gasket
4—
Cork
Gasket
5—
Oil
Cup 6—
Breather

7—
Clamp

8—
Vent
Tube 9—
Air
Pump Hose from cleaner
body
and remove the oil from the cup,
scrape all
dirt
from the inside.
Clean
oil cup thor­
oughly, wash filter
element
in a solvent that
will
leave it clean and dry.
Fill
oil cup to indicated
level with clean
S.A.E.
40 or 50 grade
engine
oil
(S.A.E.
20 grade in winter.) Assemble cleaner filter

element
to oil cup making sure that gasket is in
place
between
the two pieces. Assemble air cleaner assembly to carburetor making sure the gasket
be­

tween
air cleaner and carburetor is in place. Secure

air
cleaner to carburetor with wing nut. Service the

air
cleaner every
6000
miles
[9.600
km.],
c.
Carefully
check the
hose
clamps and
fittings
on
the breather
hoses
at frequent intervals. Loose con­nections
will
affect proper operation of the
crank­

case ventilating system.

B-26. Dry-Type
Air Cleaner Service the air cleaner on Dauntless V-6
engines

at each oil change under normal driving conditions.

If
the vehicle is operated under dusty conditions,
check the condition of the air cleaner
element
more
frequently and service if dirty.

Servicing
the air cleaner consists of cleaning or replacing the air cleaner
element
and replacing the

crankcase
ventilation filter (breather assembly). See Fig. B-7.

The
air cleaner
element
assembly consists of a
paper
element
and a polyurethane
element
The
paper
element
cannot be cleaned.

To
clean the polyurethane
element,
first carefullly remove it from the paper
element
Then
wash it in 14

B

LUBRICATION
Note:
Hard
shifting of the transmission gear in
cold weather is a positive indication that the
lubri­

cant
is of the wrong viscosity or of poor quality

which
allows it to congeal.

B-38.
Optional
4-Speed
Transmission
and
Transfer Case

The
four-speed transmission and transfer case re­

quire
separate lubrication for each unit as
they
have no cross-over oil passage. At each transmission
service check, the
fill
plugs of
both
four-speed

transmission
and transfer case should be pulled
and
the lubricant refilled to level if necessary.

B-39.
Transfer
Case
Linkage

The
transfer case shift linkage should be lubricated

periodically.
All
bearing surfaces that are assembled
with
studs and cotter pins should be disassembled, cleaned, and coated with a
good
waterproof grease.

The
bearing surfaces that cannot be disassembled
should be lubricated with a lubricant that
will
penetrate the bearing
area.
These bearings include
the two on the cross shaft assembly and the
threaded stud.

The
type
of penetrating lubricant recommended is
DuPont
"PM 7", No. 2911, or its equivalent.

B-40.
Brake Master Cylinder

Clean
the top of the
fill
cap and also the housing

area
around it. Remove the cap and observe the
fluid
level. It should be
half
an inch
below
the top
of the fill-hole. If not, add brake fluid to
half
inch
[1,3 cm.]
below
the top of the fill-hole. Use
only heavy-duty brake fluid conforming to speci­
fication
SAE-J-1703.
Be sure to handle the brake

fluid
in clean dispensers and containers that
will
not introduce even the
slightest
amount of other

liquids
or foreign particles. Replace and tighten
the
fill
cap.

B-41.
Adjust Brakes

Refer
to Section P.
B-42.
Brake Linings

Refer
to Section P.

B-43.
Adjust Clutch

Refer
to Section I.

B-44.
Clutch Cross Shaft (Lever Type)

Lubricate
the clutch cross shaft in accordance with
specifications given in the
Lubrication
chart: see
Item
1. Chassis Bearings.

B-45.
Tie Rod and Drag
Link
Sockets

The
tie rod and drag
link
sockets
are equipped

with
lubrication
fittings
and should be lubricated

per
specifications given in the
Lubrication
chart: see Item 1. Chassis Bearings.
B-46.
Front
and
Rear Spring
Bushings

The
condition of the spring bushings is indicated
by the alignment of the spring pivot and spring
shackle
bolts.
Check
the alignment of
these
bolts,

and
check that nuts are
tightened
securely.

B-47.
Spring
Shackles

Rubber
bushings are provided on the spring
shackles.
These rubber bushings have no lubrication
fitting and it is very important that
they
never be lubricated.

B-48.
Shock Absorbers

Visually
check for broken mounts or bolts, worn

or
missing bushings on the shock absorbers. Refer
to Section S.

B-49.
Front and
Rear
Axle
U-Bolts

Torque
the front and
rear
axle U-bolts. Refer to Section S.

B-50. Front
and
Rear
Axle
Differentials
—
Lubricant Levels

The
lubricant
level of all front and
rear
differentials should be at the level of the fill-hole.

B-51.
Front and
Rear
Axle
Differentials
—
Changing
Lubricant
B-52.
Conventional Differentials

To
remove the lubricant from the front or
rear
differential,
it is necessary to remove the housing cover. Let the lubricant
drain
out, and then flush
the differential with a flushing oil or light
engine

oil
to clean out the housing
(except
Powr-Lok
or
Trac-Lok
Differentials). Do not use water, steam,
kerosene, or
gasoline
for flushing.

Reinstall
the housing cover, replacing the gasket whenever necessary, torquing the cover
bolts
to 15 to 25 lb-ft. [2,1 a 3,4 kg-m.].
Remove the filler plug, and
refill
the differential
housing as specified in the
Lubrication
Specifica­
tions.

B-53.
Powr-Lok
or
Trac-Lok Differential

Some vehicles may be equipped with the
Powr-Lok

or
Trac-Lok
Differential as optional equipment.
Special
lubricant and ordinary multipurpose gear

lubricants
must
not be used. Use only
'Jeep*
Differ­

ential
Oil,
Part
No. 94557.

Powr-Lok
or
Trac-Lok
differentials may be cleaned
only by disassembling the unit and wiping with
clean
rags. Do not flush the unit. Refer to Sec­
tion N.

B-54.
Front Axle Universal Joint
—
Lube

Check
the level of the front axle universal joint
lubricant
at each front wheel by removing the
fill-hole plug. The lubricant should be level with
the fill-hole. If required, add lubricant as specified

in
Lubrication
Specifications.

B-55.
Front
Axle
Universal
Joint
— Service

On
all 4-wheel drive vehicles the front axle
uni­

versal
joint should be serviced by removing the shaft and thoroughly cleaning the universal joints

and
housing. For the correct procedures, refer to
Section M. 16

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
C-10.
Distributor
Service

The
distributor cap should be inspected for
cracks,

carbon runners and evidence of arcing. If any
of
these
conditions exists, the cap should be re­
placed.
Clean
any corroded high tension terminals. Inspect the rotor for cracks or evidence of
exces­

sive burning at the end of the metal strip. After

a
distributor rotor has had normal use the end
of the rotor
will
become
burned. If burning is found
on top of the rotor it indicates the rotor is too
short and
needs
replacing. Usually when this con­
dition is found the distributor cap
segment
will

be burned on the horizontal face and the cap
will

also need replacing.
Check
the condenser lead for broken wires or

frayed
insulation.
Clean
and tighten the connec­
tions
on the terminal
posts.
Be sure the condenser
is mounted firmly on the distributor for a
good
ground connection. Should a condenser tester be available the capacity
should be checked. In the absence of a tester check
by substituting a new condenser.
Examine
the distributor
points
(Fig.
C-ll).
If
they

show wear, poor mating, transferred metal, or pitting, then new
ones
should be installed.
Clean

the
points
with a suitable solvent and a stiff
bristled brush.
Check
the alignment of the point for a
full,
square
contact. If not correctly aligned, bend the station­
ary
contact bracket slightly to provide alignment,

a.
Hurricane F4 Engine (Prestolite).

The
contact gap of the distributor point on the

Hurricane
F4
engine
should be set at .020"
[0,508

mm.],
measured with a wire
gauge.
Adjustment of
the gap is accomplished by
loosening
the lock screw and turning adjusting eccentric screw (Fig.
C-12)
until correct gap is secured. Be sure that the
fiber block on the breaker arm is resting on the
highest point on the cam while the adjustment is being made. Recheck the gap after locking the
adjustment.

Apply
a thin film of cam lubricant to the cam to
lessen fiber block wear. Should a condenser tester be available the capacity
should check from .21 to .25 microfarads. In the
absence of a tester check by substituting a new
condenser.

Check
point contact spring pressure, which should
be
between
17 and 20
ounces
[0,487
a 0,56 kg.].
Check
with a spring scale hooked on the breaker

arm
at the contact and pull at right
angle
to the

breaker
arm. Make the reading just as the
points

separate. Adjust the point pressure by
loosening
the stud holding the end of the contact arm spring

and
slide the end of the spring in or out as neces­

sary.
Retighten the stud and recheck the pressure. Too low a pressure
will
cause
engine
missing at
high
speeds.
Too high a pressure
will
cause rapid wear of the cam, block, and points.
b. Dauntless V-6 Engine (Delco).

The
spark advance is fully automatic being con­
trolled by built-in centrifugal weights, and by a vacuum advance system (Fig.
C-13).
The same
checking procedures are used as (a)
above
except,

the capacity of the condenser must be .18 to .23 microfarads and the contact gap should be set at
.016"
[0,406
mm.]. Adjustment of the gap is made
by rotating the socket head adjustment screw with
a
Vs" [3,86 mm.] Allen wrench (Fig.
C-14).

The
contact spring pressure must be 19 to 23 ozs.
[0,538
a
0,652
gr.] and the cam dwell
angle
is

30°,
with distributor vacuum line disconnected.
The
preferred method of adjusting cam dwell re­
quires turning of the adjusting screw until the specific dwell
angle
is obtained as measured by a
dwell
angle
meter. Refer to Par. C-l7. To adjust
the cam dwell by an alternate method, turn the adjusting screw in (clockwise) until the
engine

FIG.
C-12—PRESTOLITE DISTRIBUTOR HURRICANE F4 ENGINE
1— Condenser
2—
Lubricating
Wick

3—
Breaker
Cam
4—
Breaker
Arm Pivot 5—
Distributor
Cap (Rotation &
Firing
Order)
6—
Distributor
Points 7— Adjustment
Lock
Screw
8—
Adjusting
Eccentric
Screw
9—
Oiler

10—Primary
Wire
26

'Jeep'
UNIVERSAL SERIES SERVICE
MANUAL

D
Remove the screws and lockwashers that attach
the main bearing caps to the cylinder block. Use
a
lifting bar beneath the ends of each bearing cap.

Be
careful not to exert too much pressure to cause
damage to the cap or
dowels
and pry the caps free.

CAUTION:
If main bearing caps are not removed
carefully
by raising both sides of each cap evenly

until
free of the dowels, the
dowels
may be bent.

A
bent main bearing cap dowel can cause misalign­ ment of the cap and resultant
rapid
bearing wear
necessitating replacement. Therefore, remove each
main
bearing cap carefully. If there is reason to
believe any of the
dowels
have been bent during
the bearing cap removal, remove them and install
new
dowels
as detailed in Par. D-34c.
Remove the upper
half
of the
rear
main bearing

oil
seal from the cylinder block and the lower
half

from
the oil seal
groove
in the
rear
main bearing

cap.
Install
the main bearing caps and bearings on
the cylinder block in their original positions.

Note;
Removal of the crankshaft may be ac­
complished only with the
engine
out of the vehicle.

D-27.
Remove
Exhaust
Valves and Springs
Access to the valve chamber is obtained by re­ moving the attaching parts and the valve spring
cover and gasket from the cylinder block. Use cloths
to block off the three
holes
in the exhaust valve
chamber to prevent the valve retaining locks falling
into the crankcase, should they be accidentally dropped.

With
a valve
/
spring compressor, compress the valve springs on
those
valves which are in the
closed position (valve seated against cylinder

block).
Remove the exhaust valve spring retainer

locks,
the exhaust valve spring retainer, and the exhaust valve spring. Close the other valves by
rotating the camshaft and repeat the above opera­
tion for the other valves in the same manner.
Lift

out all the exhaust valves and tag or place them in
a
rack
to indicate the location where each was re­moved from the cylinder block. If a valve sticks in
the guide and cannot be easily lifted out,
pull
the valve upward as far as possible and remove the

spring.
Lower
the valve and remove any carbon

deposits
from the valve stem.
This
will
permit re­ moval of the valve.

For
intake valve and spring removal, see
Par.
D-l7.

D-28.
Remove Camshaft

a.
Push the intake and exhaust valve tappets into the cylinder block as far as possible so the ends of
the tappets are not in contact with the camshaft. b. Secure each tappet in the raised position by in­
stalling a common clip-type clothes pin on the

shank
of each tappet or tie them up in the valve
chamber.

c. Remove the camshaft thrust plate attaching
screws.
Remove the camshaft thrust plate and

spacer.

d.
Pull
the camshaft forward out of the cylinder
block using care to prevent damage to the cam­
shaft bearing surfaces.
D-29.
Remove Valve Tappets
Remove the intake and exhaust valve tappets from
the
bottom
or crankshaft side of the cylinder block
after the camshaft has been removed. Tag each
tappet or place them in a marked
rack
so they may be reassembled in their original positions.

D-30.
Remove Oil
Gallery
Plugs
Remove the plug at each end of the oil gallery in the cylinder block.
This
operation is only applicable
when the
engine
is out of the vehicle and
will
allow access to the oil gallery so it may be cleaned.

D-31. ENGINE INSPECTION
AND
REPAIR
The
inspection and repair procedures detailed here­

in
are recommended to be followed when a com­
plete
engine
overhaul is to be made with the
engine

out of the vehicle. These instructions can generally be applied individually with the
engine
in the
vehicle. Wherever the procedure differs due to
the
engine
being in the vehicle, the necessary

special
instructions are provided. Inspection and

repair
instructions are included to cover the

cylinder
block, cylinder head, crankshaft and bearings, connecting rods and bearings, oil pump, valves and tappets, pistons and rings, flywheel,
timing gears, and the camshaft and bearings. In addition, fitting operations for
these
engine
com­

ponents
are included.

Important:
Before the inspection and repair pro­
cedures listed below are begun, the
engine
serial
number must be checked for the presence of
code

letters denoting undersize bearings or oversize
pistons. Refer to Par. D-2.

D-32.
Cylinder
Block

The
cylinder block must be thoroughly cleaned, inspected and repaired as detailed in the following

paragraphs.

D-33.
Cleaning

The
cylinder block may be steam cleaned or cleaned

with
a suitable solvent. A scraper is recommended
to remove
hard
deposits, except on highly finished surfaces. Special attention must be directed to the
cleaning of the oil passages, valve chamber,
crank­

case, and cylinder walls to remove all sludge,
dirt

and
carbon deposits. After cleaning, use air pressure to dry the block thoroughly.
D-34. Inspection

Examine
the cylinder block for minute cracks and

fractures.
Rusted valve springs or evidence of rust

in
the valve chamber or the cylinder walls is a
good

indication of a possible
crack
in the block,

a.
Examine all machined surfaces of the cylinder block for
burrs
and scores.
Check
for cylinder block
distortion by placing a straight
edge
along the
length of the cylinder head surface of the block.
With
a feeler
gauge,
check for clearance
between
the straight
edge
and the block, particularly be­
tween adjacent cylinders. Maximum permissible
out of line for service is .010"
[0,254
mm.] over the
full
length of the block. 45

'Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL

D
straight
in the hole, then tap the dowel lightly

with
a hammer until it
bottoms.

d.
When installing bearing eaps, be sure to tighten
the
bolts
evenly in each cap to
pull
it into place
without bending the
dowels
or distorting the
bearing
cap.
e. Other parts of the block which require inspec­ tion
and
possible
repair,
but which are directly
related
to other
engine
components (such as tappets, pistons, camshaft, valves, crankshaft, and

oil
pump) are covered later in this section.

D-35.
Cylinder
Bores

The
cylinder bores may be reconditioned by honing
or
reboring. Use oil-soaked rags to protect
crank­

shaft
journals
and other
engine
parts from abrasive
dust during all reconditioning operations.

Both
honing and reboring of the cylinders must be
done
carefully to fit the pistons and to obtain
specified clearances. If reboring of the cylinder bores is not required but the walls are glazed, use

a
finishing
hone
to remove the glaze. Reboring the cylinders must not be attempted unless ade­
quate facilities and experienced service technicians
are
available. The amount of material to be re­moved is determined from the original diameter
of the cylinder bores (3.125" to 3.127") [79,375 a
79,426
mm.] plus the amount of oversize in diameter
of the oversize pistons to be fitted. Pistons are
available
in the following oversizes.
.010"
[0,254
mm.] .030" [0,762 mm.] .020" [0,508 mm.] .040" [1,016 mm.}

The
largest cylinder bore
will
determine the over­
size to which all cylinders must be rebored, since the size and weight of all pistons must be uniform
to maintain proper
engine
balance. The maximum rebore should not exceed .040" [1,016 mm.] from

standard.
Measure
the cylinder diameters by making mea­
surements both parallel to and at right angles to
crankshaft
over entire piston travel and at
bottom

of cylinder. Proceed as follows:

a.
If bores are scored; if out-of-round
exceeds
.005
"
[0,127 mm.]; if diameters differ more than .005";

or
if taper
exceeds
.005
"
on diameter, it is generally
recommended that cylinders be reconditioned by
reboring
and honing to the next oversize using new
pistons of the proper size.

Note:
If reboring is performed, allow .0015"
[0,0381
mm.] for final honing.

All
cylinder bore diameters must be within .002
"
[0,0508
mm.] after reconditioning.

b.
If bore measurements are within the above

limits,
but indicate hollows or waviness, cylinders should be honed with 250 grit
stone
hone. Pump
hone
up and down in cylinder while it is rotating
to produce a satin-finish, diamond cross-hatched

pattern
approximately 30° with horizontal. Hone
only enough to correct waviness.
c. If cylinder bore correction is unnecessary, break the glaze on cylinder walls with a 250 grit
stone

hone
or with a suitable deglazing tool. Operate the
hone
or deglazer to obtain diamond cross-hatched

pattern
previously mentioned.

d.
Regardless of type of correction on cylinder
walls,
wash out bores thoroughly afterwards and
apply
a light coat of
engine
oil. If cylinders have
been rebored or honed heavily, measure cylinder
diameters again to assure proper selection of piston
size.

D-36.
Pistons, Rings, and Connecting Rods
Pistons are each fitted with three rings, two com­ pression rings and one oil control
ring.
The pistons have an extra
groove
above the top ring which acts as a heat dam or insulating
groove
to protect
against sealing of the top ring in the ring
groove

with
hard
carbon. The piston pin is secured by the lock screw.

The
pistons and connecting rods were removed from
the
engine
as assemblies. If cylinders were rebored,
new oversized pistons and rings
will
have to be in­

stalled.

Disassemble the pistons and rods. Remove the
two compression rings, the oil control
ring,
and the oil control ring expander from each piston. Do not remove the
bolts
from the lower end of the
connecting rods unless the
bolts
are damaged.
Clamp
each connecting rod and piston assembly

in
a padded bench vise and remove the piston pin

lock
screw and lockwasher. Press the piston pin
out of the piston and connecting rod.
Clean
all
carbon,
gum, and lacquer
deposits
from both the

inner
and outer surfaces of each piston, connecting

rod,
and piston pin. Use a ring
groove
cleaner or a
broken
ring filed to a sharp square
edge
to clean
the carbon from the piston ring
grooves
and the

insulator
groove. Use care not to scrape metal from
the sides of the
grooves
or make
burrs
on ring
groove
surfaces. Run a length of wire through the

oil
spray
hole
near the lower end of the connecting

rod
to clear the
hole
of hardened oil
deposits
or
foreign matter.
Carefully
inspect the pistons and
replace
any that are broken or cracked. Replace
pistons if any of the ring lands are chipped, broken,
or
rounded on the
edges;
or if the piston is scored,

scratched,
or burned so seriously that the imperfec­
tions cannot be removed with a hand honing
stone

or
crocus cloth.

Replace
the pistons as follows:

a.
After cylinder bores have been carefully checked for out-of-round and taper (Par. D-35), check fit
of each piston to cylinder bore with block and
pistons clean and dry and at approximately 70
°F.
[21°C]
by using Piston Fitting Gauge And Scale

Tool
No. C-690 as shown in Fig. D-7. Use a .003"
[0,0762
mm.] thickness
gauge
%" [19 mm.] wide.

The
piston is fitted upside down in the block to
facilitate the operation. The
gauge
must extend the
full
length of the piston on the thrust side
(opposite

side from slot in piston
skirt).
Scale should register
5
to 10 pounds [2,3 a 4,5 kg.]
pull
to remove the
thickness
gauge
from
between
cylinder
wall
and piston. Excessive
pull
indicates need for a slightly

smaller
piston or additional honing of cylinder. In­ sufficient
pull
indicates need for fitting a larger piston. 47

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

D
satisfactory bearing replacement cannot be made

and
it
will
be necessary to regrind the crankshaft.

Install
the bearing lower
half
and the connecting

rod
cap and draw the cap bolt nuts down equally
and
only slightly tight. Move the connecting rod
endwise, one way or the other, on the crankshaft to be sure the bearing is not tight.
Pull
the nuts tighter, first one then the other, a little at a time,

and
keep trying the fit of the rod on the crankshaft by hand until the recommended torque of 35 to 45 lb-ft. [4,8 a 6,2 kg-m.] is reached. If the
bearings are of the correct size, and have been
properly
lubricated with light
engine
oil before in­

stallation,
the connecting rod should be easy to
slide back and forth parallel to the
crankpin.
If
the connecting rod is tight on the crankshaft, a

larger
bearing is required. If there is no binding

or
tightness, it is
still
necessary to check clearance
to guard against too
loose
a fit. The use of "Plasti­

gage"
or shim stock of the proper size to measure .001" [0,025 mm.] clearance is recommended for

checking
connecting rod bearing clearances.
This

is the same material recommended for checking
crankshaft
main bearings and the method of check­
ing is
similar.
Refer to
Par.
D-45 or D-46. Connect­
ing rod bearings are fitted to the same clearance as the main bearings but the torque specified for con­
necting rod cap
bolts
is different.

D-50.
Connecting
Rod
Side Play

Check
the connecting rod side play with a feeler
gauge
as shown in Fig. D-l8. The side clearance is .004" to .010"
[0,101
a
0,254
mm.].

D-51.
Camshaft and Bearings

The
camshaft is supported at four points in the

cylinder
block. The front is supported in a re­ placeable, steel-shell, babbit-lined bearing. The

bearing
is pressed into place The other three bear-
FIG.
D-18—CONNECTING
ROD
SIDE
PLAY
ing surfaces are precision machined in the cylinder
block. The camshaft bearings are pressure
lubri­

cated through drilled passages in the crankcase.

End
thrust of the camshaft is taken by a thrust plate bolted to the crankcase. The camshaft is

driven
by a silent helical-cut
tooth
timing gear at
the front of the engine. A worm gear, integral with
the camshaft, drives the oil pump and distributor.

The
fuel pump is actuated by an eccentric forged

onto
the camshaft.

Clean
the camshaft thoroughly in cleaning solvent.
Inspect
all camshaft bearing surfaces to determine

if
they are scored or rough. The cam faces must be
perfectly smooth throughout their contact face

and
must not be scored or worn.

D-52.
Camshaft
Front Bearing Replacement

Use
a suitable driver to remove the camshaft front
bearing
from the cylinder block. To install a new
bearing,
align the oil
hole
in the bearing with the
bored oil
hole
in the cylinder block and drive the

bearing
in until the front end of the bearing is

flush
with the front surface of the cylinder block.

Make
sure the oil
hole
is open and clear. It is not
necessary to line-ream the bearing after installation because bearings for replacement are precision
reamed
to the finished size. Do not stake the

bearing.

D-53-
Camshaft End Play

End
play of the camshaft is determined by running
clearance
between
the
rear
face of the camshaft gear and the thrust plate and is established by the

spacer
thickness. The standard clearance is .004"
to .007"
[0,101
a 0,178 mm.] and can be measured by a
dial
indicator. As a general rule this clearance

will
change but little through wear or when a new gear is installed. To predetermine the correct end
float with the gear, spacer, and thrust plate re­
moved, measure the thickness of both the thrust
plate and spacer with a micrometer. The thickness
of the spacer should be approximately .006" [0,152 mm.] greater than that of the thrust plate.

When
this is correct and the parts are assembled

and
drawn tightly
together
by the gear retaining

screw,
the end play should
come
within standard
limits.

D-54.
Timing Gears
and
Cover

The
timing gears are mounted at the front of the
engine. Camshaft drive is through helical-cut
timing gears; a steel gear on the crankshaft and a
pressed fiber gear on the camshaft. The gears are keyed to their respective shafts. The camshaft

driven
gear is secured on the front end of the
camshaft by means of a capscrew and a plain

washer.
The crankshaft gear is secured on the
front end of the crankshaft by a nut threaded
onto
the front end of the crankshaft holding the
crank­

shaft pulley, crankshaft oil slinger, and the
crank­

shaft drive gear spacer. The timing gears are

lubricated
through a jet threaded into the
crank­
case directly above the gear contact and oil supplied
through a drilled passage from the front main

bearing.
The timing gears are enclosed by the
sealed timing cover. The oil seal in the cover bears 53

HURRICANE
F4
ENGINE

FIG.
D-28-
CHECKING
OIL
PUMP
ROTORS

FIG.
D-29—CHECKING OUTER ROTOR
TO
OIL
PUMP
BODY If,
however, the
teeth
are broken, cracked, or
seriously
burred,
the ring gear should be replaced.

D-69.
Ring
Gear
Replacement

The
ring
gear
is secured on the flywheel by a
shrink

fit. Before starting the operation of replacing the
ring
gear, place the new ring gear against the old
gear to make certain both have the same number of
teeth.

To
remove the ring gear from the flywheel,
drill
a [9,5 mm.]
hole
through the ring gear and cut
through any remaining metal with a cold chisel. Remove the ring gear from the flywheel. Thorough-
FIG.
D-30—CHECKING
OIL
PUMP
COVER
ly
clean the ring gear surface of the flywheel. Heat
the new ring gear evenly to a range of
650°F.
to
700°F.
[343°C.
a
371°C.]
and place it on the cold
flywheel,
making
certain that the chamfer on the
teeth
is on the crankshaft side of the flywheel. Be

sure
that the ring gear is firmly seated on the fly­
wheel. Allow the ring gear to cool slowly to
shrink
it
onto
the flywheel. Do not quench the ring gear;
allow it to slowly air cool.

D-7Q.
Flywheel Pilot Bushing

Inspect
the flywheel pilot bushing in the flywheel.

For
procedure on replacing the bushing, refer to

Par.
1-8.

D-71.
Flywheel Housing

The
flywheel housing, which
encloses
the flywheel

and
clutch is bolted to the
engine
rear
plate and
cylinder
block. The
rear
of the housing provides
the front support for the transmission. Examine the housing for cracks and distortion of the

machined
surfaces. The front face must seat evenly
against the
engine
rear
end plate without evidence
of warpage. The
rear
face must be parallel to the front face. Improper alignment may cause trans­mission gear disengagement. In addition, the open­
ing in the
rear
of the housing, which serves as a
pilot for the transmission, must be concentric with the crankshaft. The flywheel housing should be
checked for alignment after it is installed on the
engine. Refer to Par. D-88.

D-72.
Core Hole Expansion Plug

Any
evidence of coolant leakage around any of
the core
hole
expansion plugs
will
require replace­ ment of the plug. The expansion plug at the
rear

end of the cylinder block can be driven out with a 24" [60 cm.] length of half-inch bar stock carefully
inserted through the camshaft bore in the cylinder
block. The other core
hole
expansion plugs in the
cylinder
block and cylinder head can be removed
by piercing the center with a sharp tool and prying them out. Before attempting to install a new plug,
clean
the
hole
thoroughly. Apply a thin coat of
sealer on the new plug and install the plug with a
driver.
60