reset JEEP DJ 1953 Service Manual

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

'Jeep9
UNIVERSAL
SERIES
SERVICE
MANUAL

h.
Check
ignition (distributor) timing; reset if
necessary.

i.
Check
carburetor
adjustments; reset if necessary,

j.
With
engine
fully warmed up, tighten cylinder
head and manifold
bolts
and nuts to specified
torque.
Check
cylinder head gaskets and
bolts
for
air
or coolant leaks.

Note:
Tightness of cylinder head
bolts
should be
checked and corrected after 500 to 600 miles [800

a
960 km.] of normal operation.

k.
Check
fan belt tension; adjust if necessary.

I.
Check
for and correct any oil leak, fuel leak or
coolant leak.
D-107.
VALVE
ADJUSTMENT

Proper
valve adjustment is important to prevent
burning
of valves and poor
engine
performance.

This
adjustment consists of obtaining a specified

lash
in the valve mechanism. The exhaust valve
tappets and the intake valve rocker arms should be adjusted to the proper clearance with the
engine

cold (at room temperature). Valve clearance can
be properly adjusted only when the tappet is on the
heel or low portion of the cam.
INTAKE

OPENS

9°
BTC?

FIG.
D-43-
10270

-VALVE
TIMING
D-108. Valve Adjustment Procedure

The
exhaust valve tappets are adjusted by turning
the adjusting screw in or out of the tappet as neces­
sary
to obtain the proper clearance. Where special
wrenches can be obtained, they should be used to facilitate the adjustment. The proper clearance is .016" [0,406 mm.]
between
the end of the adjusting
screw and the
bottom
of the exhaust valve.

Crank
the
engine
over to
close
a valve and check
the clearance with a feeler
gauge.
To adjust, hold
the tappet with one wrench and
turn
the adjusting

screw,
with the other.
Check
and adjust each of
the tappets in proper sequence.

Adjust
each intake valve by adjusting the rocker
arm
screw at the push rod to obtain .018" [0,457 mm.] clearance
between
the rocker arm and the
valve stem with tappet on the heel of the cam.
D-109.
Check
Valve
Timing

To
check the valve timing, carefully set the intake
valve rocker arm adjustment for No. 1 cylinder to .026"
[0,6604
mm.]
between
the rocker arm and the
valve stem. Rotate the crankshaft clockwise until
the piston in No. 1 cylinder is ready for the intake stroke. The intake valve
opens
9° before top center
(BTC).
Note
the distance
between
the
"TC"
and
"5°"
marks on the indicator on the timing gear
cover and estimate the 9° before top center position.
See
Fig.
D-43.
With
the crankshaft in this position, timing is correct if the rocker arm is just tight
against the intake valve stem. Do not overlook resetting the rocker arm adjustment to the correct

running
clearance.
D-110. Positive
Crankcase
Ventilation

Be
sure there are no air leaks at the tube connec­
tions
between
the air cleaner and the oil filler tube,

and
that the oil filler tube cap gasket is in
good

condition. Always keep the cap locked securely in
place. When tuning the
engine
or grinding valves, remove the control valve and clean it thoroughly.
If
the valve is blocked with carbon, the ventilating
system
will
not operate and, should the valve

fail
to seat, it
will
be impossible to make the
engine

idle satisfactorily. Refer to Par. C-6 for servicing.
D-111. Oil
Filter

The
engine
is equipped with a throw-away type

oil
filter.
This
oil filter must be serviced periodi­
cally
as outlined in the
Lubrication
Section. 69

D

HURRICANE
F4
ENGINE
D-112.
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

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

Defective
Spark Plugs—Clean or Replace
Defective
Breaker Points—Replace
Points

Incorrect Breaker Point Gap—Reset
Points

Defective
Condenser or Coil—Replace
Loose Electrical Connections—Locate and Tighten
Broken Valve Spring—Replace Spring Broken Piston or Rings—Replace
Defective
Head Gasket—Replace Gasket
Cracked
Distributor Cap—Replace Cap

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 Burned Valves and Seats—Continued
Valve Tappet Sticking
Valve Tappet Clearance Incorrect
Clogged
Exhaust System
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
Thermostat 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

Popping-Spitting-Detonation
Improper Ignition
Improper Carburetion
Excessive Carbon
Deposit
in Combustion
Cham­
bers
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
Excessive Oil Comsumption 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 70

Dl

DAUNTLESS
V-6
ENGINE
e.
Connect electrical wiring harness to coolant
temperature sending unit. Connect two distributor leads to ignition coil. Connect fuel line
between

fuel pump and carburetor, vacuum
hose
between
distributor and carburetor, and crankcase vent
hose

to intake manifold
below
rear
of carburetor.
FIG.
D1-46—-INTAKE
MANIFOLD
INSTALLATION

1—Long Bolt 2—Open Bolt Hole
Dl-102.
ENGINE INSTALLATION

Install
the
engine
in the vehicle in the following
procedure listed
below:

a.
Attach suitable sling to
engine
lifting
eyes
and,
using a hoist, lift the
engine
from blocks or
engine
stand.
b. When
engine
is free of the stand lower it slowly

into
the
engine
compartment of the vehicle.

Note:
The
engine
and transmission must be lined
up to
engage
the main shaft and clutch plate spline
while sliding the
engine
rearward
into
the mounting
position.
c.
Install
and tighten up
bolts
securing
engine
to
flywheel housing.

d.
Install
and tighten front
engine
mounting bolts.

e.
Remove sling from the
engine.

I.
Connect exhaust pipes to right and
left
engine
manifolds.
g. Connect choke cable support bracket to
car­

buretor.

h.
Connect
engine
fuel
hoses
and fuel lines at right
frame
rail.

I.
Connect fuel lines.

j.
Mount
engine
starter motor assembly to
engine.
k.
Connect battery cable and wiring to
engine

starter
motor.

I.
Connect
engine
wiring harnesses to connectors
located on
engine
firewall.

Note:
On
engines
equipped with exhaust emission
control, replace the air pump, air distributor mani­
fold, and anti-backfire (gulp) valve. See Section F2.
m. Replace radiator, and secure with bolts,
n.
Replace and tighten right and
left
radiator sup­
port rods.
0. Connect upper and lower radiator
hoses
to the

engine.
p. Connect alternator wiring harness from connec­
tor at regulator,
q.
Replace air cleaner.
r.
Connect battery ground cable from the battery
to the
engine
and the
engine
ground strap,

s.
Replace the hood.

After
the
engine
is installed in the vehicle,
fill
radiator
with coolant and
engine
with oil (Refer to
Lubrication
Section B), then perform an
engine

Tune-up
and road
test
(Refer to Tune-up Sec­
tion C).

Dl-103.
FINAL IN-VEHICLE ADJUSTMENTS

a.
Clean
battery terminals and check battery.
b.
Check
ignition wires and connections.
c. Service carburetor air cleaner.

d.
Service positive crankcase ventilation valve.
e.
Check
fuel lines.
f. Gap and install new
spark
plugs.
g.
Check
distributor
points
and capacitor; replace
if
necessary.

h.
Check
ignition (distributor) timing; reset if
necessary. 1.
Check
carburetor adjustments; reset if necessary,

j.
With
engine
fully warmed up, tighten cylinder
head and manifold
bolts
and nuts to specified
torque.
Check
cylinder head
gaskets
and
bolts
for
air
or coolant leaks.

Note:
Tightness of cylinder head
bolts
should be
checked and corrected after 500 miles [800 km.]
of normal operation and again at 1000 miles [1600

km.].
k.
Check
fan belt tension; adjust if necessary.
I.
Check
for and correct any oil leak, fuel leak or
coolant leak. 104

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

Fl
b. Connect tachometer to
engine.

c.
Warm
up
engine
and stabilize temperatures.

d.
Adjust
engine
idle to
speed
desired, using throt­
tle idle
speed
adjusting screw.

e.
Carburetors without Idle
Limiter
Cap turn idle mixture screws out (counterclockwise) until a
loss

of
engine
speed
is indicated; then, slowly turn mix­
ture screw in (clockwise-leaner) until maximum

speed
(RPM) is reached. Continue turning in (clockwise) until
speed
begins
to drop; turn mixture
adjustment back out (counterclockwise-richer) un­

til
maximum
speed
is just regained at a "lean as
possible" mixture adjustment.

Fl-14.
Distributor

Check
the distributor number for proper appli­
cation.
Check
the distributor cam dwell angle and
point condition and adjust to specifications or re­ place as required. (Specifications listed at the end
of this section)
Check
ignition timing and set at

0°
or
TDC.

Fl-15.
Anti-iackfire
Diverter Valve

The
anti-backfire valve remains closed
except
when
the throttle is closed rapidly from an
open
position.

To
check the valve for proper operation, accelerate
the
engine
in neutral, allowing the throttle to
close

rapidly.
The valve is operating satisfactorily when
no exhaust system backfire occurs. A further check
to determine whether the valve is functioning can be made by removing from the anti-backfire valve
the large
hose
Which
connects to the check valve.
Accelerate the
engine
to allow the throttle to
close

rapidly.
The valve is operating satisfactorily if a
momentary interruption of rushing air is audible.

Fl-16.
Check Valve

The
check valve prevents the reverse flow of ex­
haust
gases
to the pump in the
event
the pump
should, for any reason,
become
inoperative or should exhaust pressure ever
exceed
pump pressure.

To
check this valve for proper operation, remove the air supply
hose
from the pump at the
distri­

bution manifold.
With
the
engine
running, listen for exhaust leakage at the check valve which is
connected to the distribution manifold.

Fl-17.
Air
Pump

Check
for proper drive belt tension with belt tension
gauge
W-283. The belt strand tension should be

50-60
pounds on a belt with previous service, meas­

ured
on the
longest
accessible span
between
two pulleys. When installing a new belt, adjust the
tension to
60-80
pounds tension. DO NOT PRY
ON
THE DIE
CAST
PUMP
HOUSING.

To
check the pump for proper operation, remove the air
outlet
hose
at the pump.
With
the
engine

running,
air discharge should be
felt
at the pump

outlet
opening. The pump
outlet
air pressure, as determined by the relief valve, is preset and is not
adjustable.

The
air pump
rear
cover assembly, housing the pressed in inlet and discharge tubes, and the pres­
sure relief valve are the only pump
components

recommended for service replacement. These parts
are
to be replaced only when damaged as a result
of handling or in the
event
the relief valve was
tampered with.

Fl-18.
Carburetor
Air
Cleaner

Every
6000
miles
[9,600
km.] clean the inside
sur­

face at the sump and
refill
to indicated oil level with
SAE
40 or 50
engine
oil
above
32 F; SAE 20

below
32 F. Wash filter
element
in kerosene and

drain.
Reassemble the air cleaner.

More
frequent cleaning and replacement is advis­ able when the car is operated in dusty areas or on
unpaved roads. Accumulated dirt restricts air flow,
reducing fuel
economy
and performance.

Fl-19.
REMOVAL
PROCEDURES

The
following paragraphs
give
the procedures for removing the major units of the Exhaust Emission

Control
System and the required equipment
needed.

Fl-20.
Air
Pump

Loosen
the air pump adjusting strap to facilitate

drive
belt removal. Remove the air pump air dis­
charge hose(s) and air filter attachment. Separate
the air pump from its mounting bracket. At time of installation, torque tighten the air pump mount­ing
bolts
to
30-40
lbs-ft. [4,15 a 5,53 kg-m.]. Adjust
the belt strand tension to
50-60
pounds on a belt
with previous service and
60-80
pounds on a new
belt.

Fl-21.
Anti-Backfire
Diverter Valve

The
anti-backfire diverter valve removal requires disconnecting the
hoses
and bracket to
engine
at­
taching screws.

Fl-22.
Air
Distribution
Manifold
and
Injection Tubes

In
order to remove the air distribution manifold
without bending the tubing, which could result in
fractures
or leakage, it is necessary to remove the
exhaust manifold as an assembly from the
engine.

After
the exhaust manifold assembly is removed
from
the
engine,
place the manifold in a vise and

loosen
the air distribution manifold
tube
retaining nuts at each cylinder exhaust port. Tap the injec­
tion
tubes
lightly to allow the air distribution mani­
fold to be pulled away partially from the exhaust manifold. The stainless steel injection
tubes
in the
exhaust manifold may have
become
partially fused
to the air distribution manifold and, therefore, may
require
application of heat to the joint in order to
separate. While applying heat to the joint, rotate
the injection
tubes
with pliers being careful not to
damage the
tubes
by applying excessive force.

At
time of installation, the air injection
tubes
must
be positioned into the exhaust manifold prior to
placing the exhaust manifold assembly on the en­ gine.

Note:
Two different length injection
tubes
are used.

The
shorter length injection
tubes
must be inserted into cylinders 1 and 4. 145

F2
EXHAUST EMISSION CONTROL SYSTEMS
the throttle
stop
screw to idle the
engine
at 650
to 700 rpm.

F2-17. Carburetor Idle Setting
The
"Lean
Best
Idle"
Method of Idle Setting is as
follows:

a.
Any scheduled service of ignition system should
precede this adjustment

b.
Connect tachometer to engine.

c.
Warm
up
engine
and stabilize temperatures.

d.
Adjust
engine
idle to speed desired, using throt­
tle idle speed adjusting screw.
e.
Turn
idle mixture screws out (counterclockwise)

until
a
loss
of
engine
speed is indicated; then slowly
turn
mixture screws in (clockwise-leaner)
until
maximum speed (rpm) is reached. Continue

turning
in (clockwise) until speed begins to drop;

turn
mixture adjustment back out (counterclock­
wise-richer)
until maximum speed is just regained

at
a "lean as possible" mixture adjustment.

F2-18. Distributor
The
ignition distributor used with the
Exhaust
Emission
Control
System is the same as that used
on
engines
without
Exhaust
Emission
Control.
Check
the distributor cam dwell angle and point
condition.
Check
ignition timing and adjust to specifications shown on the last
page
of this section.

F2-19.
Anti-Backfire
Valve

The
anti-backfire valve remains closed except when
the throttle is closed rapidly from an open position.
To
check the valve for proper operation, accelerate
the
engine
in neutral, allowing the throttle to close

rapidly.
The valve is operating satisfactorily when
no exhaust system backfire occurs. A further check
to determine whether the valve is functioning can
be made by removing from the anti-backfire valve
the large
hose
which connects the valve to the

pump.
With
a finger placed over the open end of
the
hose
(not the valve), accelerate the
engine
and allow the throttle to close rapidly. The valve is
operating satisfactorily if a momentary air rushing
noise is audible.

F2-20.
Check
Valve

The
check valves in the lines to the air distribution manifolds prevent the reverse flow of exhaust
gases

to the pump in the event the pump should, for

any
reason,
become
inoperative or should exhaust

pressure
ever exceed pump pressure.

To
check this valve for proper operation, remove the air supply
hose
from the pump at the check

valve.
With
the
engine
running, listen for exhaust
leakage at the check valve which is connected to
the distribution manifold.

F2-21.
Air
Pump

Check
for proper drive belt tension with belt tension
gauge
W-283. The belt strand tension should be 60 pounds measured on the
longest
accessible span
between two pulleys. DO NOT PRY ON THE

DIE
CAST
PUMP
HOUSING. To
check the pump for proper operation, remove
the air
outlet
hose
at the pump.
With
the
engine

running,
air discharge should be felt at one of
the pump
outlet
openings. The pump
outlet
air
pressure,
as determined by the relief valve, is preset
and
is not adjustable.

The
air pump
rear
cover assembly, housing the pressed in inlet and discharge tubes, and the pres­
sure
relief valve are the only pump components
recommended for service replacement. These parts
are
to be replaced only when damaged as a result
of handling or in the event the relief valve was
tampered with.

F2-22.
Intake Manifold

Intake
manifold leaks must not be overlooked. Air
leakage at the intake manifold may be compen­
sated for by
richer
idle mixture setting, however, this
will
usually cause uneven fuel-air distribution
and
will
always result in
loss
of performance and
exhaust emission control. To check for air leakage
into the intake manifold, apply kerosene or naph­
tha,
on the intake manifold to cylinder head joints

and
observe whether any changes in
engine
rpm

occur.
If an air leak is indicated, check the mani­
fold to cylinder head bolt torque. The correct torque is 25-35 lbs. ft. [3,46 a 4,84 kg-m.]. If the

leak
is
still
evident,
loosen
the manifold assembly

and
torque-tighten the bolts evenly.
Start
from the center and use proper torque values. Replace the
manifold
gasket if the leak
still
exists.
Clean
both
mating surfaces and check for
burrs
or other ir­

regularities.

Always
torque the bolts evenly to the specified
torque value to prevent warpage.

F2-23.
Carburetor
Air
Cleaner
—Oil
Bath

Every
6,000
miles [9,600 km.] disconnect attach­

ing
hoses
and unscrew the wing nut from the top
of the air cleaner and lift it off the carburetor.

Lift
the cover and filter element off the oil sump.

Clean
the inside surface of the sump and
refill
to

indicated
oil level with SAE 40 or 50
engine
oil
above 32 F; SAE 20 below 32 F.
Wash
filter element in kerosene and
drain.
Reassemble the air

cleaner
and install on carburetor.

More
frequent cleaning and replacement are advis­ able when the car is operated in dusty areas or on

unpaved
roads. Accumulated
dirt
restricts air flow,
reducing
fuel economy and performance.

F2-24.
REMOVAL PROCEDURES
The
following paragraphs
give
the procedures for removing the major units of the exhaust emission
control
system and the required equipment needed.

F2-2S.
Air
Pump

Loosen
the air pump mounting bracket bolts. Re­ move the air pump air hose(s). Separate the air pump from its mounting bracket. At time of install­
ation,
torque tighten the air pump mounting bolts
to
30-40
lbs.-ft [4,15 a 5,53 kg-m.].
Adjust
the
belt strand tension to 60 pounds. 156

G
COOLING SYSTEM and
the outlet
hose
is connected to the water pump
housing.
When
installing a new hose, clean the pipe connec­
tions and apply a thin layer of nonhardening seal­
ing compound. Hose clamps should be properly
located over the connections to provide secure fastening. The pressurized cooling system pressure

can
blow off improperly installed hoses.

G-8.
Cylinder
Block

Any
coolant leaks at the engine block water joints

are
aggravated by pump pressure in the water

jacket
and by pressure developed in the cooling system when the pressure cap is in place.
Small
leaks showing up only as moist
spots
often
cannot
be detected when the engine is hot except by the
appearance of rust, corrosion, and dye stains where
leakage evaporated. Also, expansion and contrac­ tion of the engine block resulting from extreme
temperature changes can aggravate leaks. For
these

reasons, when checking for coolant leaks inspect
the block when it is cold and while the engine is

running.
A
leaking
drain
cock or plug that cannot be stopped

leaking
by tightening should be replaced.
Leaking

core-hole expansion plugs should be replaced.
If
tightening gasketed joints
will
not correct leak­
age, install new gaskets. Use a sealing compound
where recommended.

G-9.
Thermostat
a.
The cooling system of the engine is designed
to provide adequate cooling under most adverse conditions. However, it is necessary to employ
some

device to provide quick warming and to prevent
overcooling during normal operation. Automatic
control
of engine operating temperature is provided
by a water flow control thermostat installed in the
water
outlet of the
Hurricane
F4 engine. The ther­
mostat is a heat-operated valve. It should always
be maintained in working order and the vehicle
should never be driven without one installed as there would then be no control of engine tempera­

ture.
The temperature at which the thermostat
opens
is preset and cannot be altered.

b.
The thermostat on the
Hurricane
F4 engine is
located in a housing on the top front of the cylinder

head.
On the Dauntless V-6 engine it is located
in
the thermostat housing of the air intake manifold.

The
standard engine thermostat for the
Hurricane

F4
and Dauntless V-6 engine has a normal rating
of
190°F.
[87.8°C]
and should begin to open at

a
coolant temperature between
180°F.
[82°C]
to
192°F.
[89°C]
and be fully open at
202°F.
[94°C.].
See Fig. G-7 for method of testing.

When
the thermostat is not operating properly, the engine may
run
too hot or too cold. Overheating

may
damage the thermostat so that its valve
will

not function properly, and a cold engine
will
not achieve
full
efficiency.
Rust
can also interfere with
thermostat operation. To
test
the thermostat, place

it
in water heated approximately
25°F.
[17°C]
above the temperature stamped on the thermostat

valve.
Submerge the bellows completely and agitate
the water thoroughly. The valve should open fully.
Next, place the thermostat in water heated approxi-
FIG.
G-7—THERMOSTAT
TEST

mately 10°F.
[11°C]
below the temperature
stamped on the thermostat valve. Submerge the bellows completely and agitate the water thorough­
ly.
The valve should close completely. If the ther­
mostat fails either of
these
tests, it should be re­ placed with a new one of the same type and rating.

G-10. Temperature
Sending Unit

The
sending unit incorporates a temperature sens­ ing element that when it is surrounded by cold engine coolant, the unit provides the highest resist­
ance in the temperature
gauge
indicator
circuit.
Resultant
low current flow in the circuit causes the

indicator
on the instrument panel to read at the low (C) end of the
gauge.
As engine coolant tem­

perature
increases, the resistance of the unit is
decreased allowing an increased current flow in
the
circuit,
making the instrument panel
gauge

register in proportion to the temperature of the engine coolant.

To
test
the sending unit, first run the engine until

it
has had time enough to warm up.
If
no reading is indicated on the
gauge,
check the
sending unit to
gauge
wire by removing the wire

from
the sending unit and momentarily grounding
the wire. If the
gauge
now indicates, the sending

unit
is faulty. If the
gauge
still
does
not indicate, the wire is defective.
Repair
or replace the wire,

a.
Hurricane
F4 Engine.

The
thermo-couple coolant temperature sending
unit
is mounted in the right
rear
of the cylinder head (Fig. G-8) and is connected by a single wire
to the dash unit of the instrument cluster. 166

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

G
cation period. It is
good
preventive maintenance to
replace a badly frayed, worn or cracked fan belt
before it breaks in operation.

To
replace the fan belt,
loosen
the attaching
bolts

at each generator or alternator brace-to-engine mounting and pivot the alternator or generator to­

ward
the
engine
to gain slack needed to install the new belt Remove the old belt. Position the new
belt over the fan pulley, over the crankshaft pulley,
then over the generator or alternator pulley.
Pull
the generator or alternator away from the
engine

until
belt tension is
firm.
Then tighten the generator

or
alternator mounting
bolts
and check the tension
as indicated above. Reset the generator or alternator as necessary for correct belt tension.
Finally,
torque
the generator or alternator mounting
bolts
25 to 35 lb-ft. [3,4 a 4,8 kg-m.].

Note:
On the Dauntless V-6
engine
when adjusting
the fan belt tension, the alternator mounting
bolts

should be torqued 30 to 40 lb-ft. [4,14 to 5,53

kg-m.].
If a fan belt tension
gauge
(W-283) is
avail­

able, proper tension should be 80 pounds [36,2 kg.].

G-l
9. Engine Overheating

An
engine
will
not be damaged by high coolant
temperatures unless the coolant boils. The pres­

surized
cooling system on the 'Jeep' vehicles raises the boiling point of the coolant solution. Should
overheating be encountered, and the fault is be­
lieved to be in the cooling system check for the
following:

a.
Proper coolant level. See
Filling
Cooling Sys­
tem Par. G-2.
b. Poor air flow.
Check
for dirty radiator core. (See Radiator Par. G-5).
Check
for faulty belt
pulley operation, worn or
loose
fan belt, or dam­ aged fan.
Clean,
repair, replace or adjust as neces­

sary.

c. Foaming coolant.
Check
for air leaks at water
pump,
hose
connection and filler cap. Tighten, re­

pair
or replace as necessary.

d.
Surging or "after boil".
Check
pressure cap and
replace if valves or gasket are faulty.
e.
External
leaks.
Check
the following for leaks:
Hoses and clamps, water pump, radiator, head gas­
ket, core plugs and drain cocks, as well as the cylin­ der head or block for
cracks.

f.
Internal
leaks.
Check
for faulty head gasket,
cracked
cylinder head or block.
g. Poor coolant flow.
Check
hose
condition, water pump, fan belt, and repair or replace as necessary. Inspect block for rust or scale, and clean and flush
the system, if necessary.

h.
Check
the temperature
gauge.
169

'Jeep1
UNIVERSAL
SERIES SERVICE
MANUAL

H
will
cause the battery to gas excessively and
will

shorten the life of the ignition contacts and, in

general,
will
have a detrimental
effect
on all con­
nected load.

Connect
an ammeter in series with the regulator
"B"
terminal and the lead removed from the termi­

nal.
Run the generator at a medium speed and per­

form
the following operation. After each
test
is
completed reconnect whatever leads have been opened.

H-51.
Test One
Disconnect the field lead at the generator.

a.
Output drops to zero—shorted field circuit in regulator or in wiring harness. See
test
2.

b.
Output
does
not drop—shorted field circuit in
generator. Inspect generator.

H-52.
Test Two
Disconnect the field lead at the regulator.

a.
Output drops to zero—shorted field in regulator.
See
test
3.

b.
Output
does
not drop—shorted wiring harness.

Repair
or replace wiring harness.

H-53.
Test
Three

Remove the regulator cover and hold the
voltage

regulator contacts open.

a.
Output drops to zero—regulator contacts stick­

ing,
regulator out of adjustment, or regulator in­ operative.
Check
operation
(test
5), check for high
resistance
(test
4), and clean contacts per instruc­
tions in Par. H-56.

b.
Output
does
not drop—shorted field circuit in
the regulator.
Clean
the regulator contacts and in­ spect the regulator visually for incorrect wiring be­
tween units and shorted leads.

H-54.
Test
Four

Operate
the units at 10 amperes output and meas­

ure
the
voltage
drop from the regulator base to
the generator frame.

a.
Voltage reading below .03 volts—ground
cir­
cuit
is satisfactory. See
test
5.

b.
Voltage reading above .03 volts—Inspect ground

circuit
for poor connections and eliminate the high
resistance. See
test
5.

H-56.
Test
Five

Connect
a headphone from the regulator field ter­
minal
to the base and hold the current regulator
contacts closed.

a.
A steady beat is heard—voltage regulator oper­
ating.
Reset regulator as in the operation
test,

Par.
H-47.

b.
An unsteady beat is heard—dirty or sticking
contacts.
Clean
contacts per instructions in Par.

H-56.
c.
No beat is heard—inoperative
voltage
regulator
unit.
Adjust regulator operation as in the operation

test.
If the regulator cannot be adjusted within
limits,
remove for overhaul.
H-56.
Cleaning of Contacts

Clean
the
voltage
regulator contacts with a #6

American
Swiss cut equalling file.
File
lengthwise

and
parallel to the armature and then clean the
contacts with clean linen tape.
First
draw a piece
of tape that has been wet with carbon tetrachlor­
ide
between
the contacts then follow with dry tape. Reset the regulator operation as in the oper­
ation
test,
Par. H-47.

H-57.
Low Battery and a Low or No Charging Rate

Check
all wiring for
loose
connections, frayed in­
sulation and high resistance connections and cor­
rect
any fault.

Make
sure the generator operates correctly with­
out the regulator in the
circuit.
Remove the "A"

and
"B" leads from the regulator and connect an
ammeter
between
them. Remove the field lead from
the regulator and while operating at idle speed
touch the field lead to the regulator base. Increase
the speed slowly noting the charging rate. Do not

increase
the output above the rated output of the generator. If the generator output
will
not build

up,
inspect the wiring harness for shorts and
opens

and
remove the generator for an overhaul.

Connect
an ammeter
between
the battery lead and
the regulator
"B"
terminal. Connect the field lead to the regulator "F" terminal and connect the

armature
lead to the regulator
"A"
terminal.
Con­

nect a voltmeter from the regulator
"A"
terminal to
the regulator base. Operate the generator at a medium speed and perform the following
tests:

H-58.
Test Six

Read
the voltmeter.

a.
Voltage builds up—open series
circuit.
See
test
7.
b.
Voltage
does
not build up—regulator out of ad­
justment, field circuit open, grounded series
circuit.
See
test
8.

H-59.
Test Seven
Remove the regulator cover and with the generator
operating at a medium speed hold the circuit

breaker
contacts closed.

a.
Ammeter shows no charge—open
circuit
breaker
shunt winding, incorrect setting of circuit breaker,

or
dirty contacts.
Clean
contacts and reset circuit

breaker
as in
Par.
H-47d. If the circuit breaker
can­
not be set, the shunt coil is open and the regulator
should be removed for overhaul.

b.
No generator output—clean the circuit breaker
contacts and try the
test
again. If there is
still
no
charge the series windings are open and the regu­

lator
should be removed for overhaul.

H-60.
Test
Eight

Run
the generator at idle speed and momentarily
connect a jumper from the
F-terminal
to the regu­

lator
base.

a.
Voltage builds up—open field circuit or regula­
tor out of adjustment. See
test
9.
b.
Voltage
does
not build up—grounded series
cir­

cuit.
Remove regulator for overhaul. 193

'Jeep*
UNIVERSAL SERIES SERVICE
MANUAL

m
FRONT fiXLE

Contents

SUBJECT
PAR.

GENERAL.
M-l

4-WHEEL DRIVE FRONT
AXLE.
M-2
Maintenance
Requirements M-3

FRONT AXLE REMOVAL
.M-4

AXLE
SHAFT REMOVAL
M-5

REMOVING
AND
OVERHAULING
DIFFERENTIAL
.M-6

AXLE
SHAFT UNIVERSAL JOINT SERVICE
M-7

STEERING
KNUCKLE SERVICE
M-8
Replacing
Steering
Knuckle
Oil Seal M-10

M-1. GENERAL
The
front axle for all 'Jeep* Universal models,

which
have 4-wheel drive, is described in
Par.
M-2.
The
front axle for all DJ-5, DJ-6 models, which
have 2-wheel drive, is described in
Par.
M-l5.

M-2. 4-WHEEL-DRIVE FRONT AXLE
The
front axle is a live driving unit with hypoid

type
driving gears and spherical steering knuckles mounted m pivot pins which ride on tapered roller bearings for
ease
of steering. The drive is of the
full
floating
type
through axle shafts built integrally

with
cardan cross universal joints which revolve in the steering knuckles. The steering knuckle tie rod

arm
is made integrally with the knuckle. The
knuckles
are connected by a divided tie rod to a steering bell
crank.
A steering connecting rod con­

nects
the bell
crank
to the steering gear arm. The

divided
tie rod is adjustable and the
toe-in
of each
front wheel is adjusted independently.
Camber
and
SUBJECT
PAR.

REASSEMBLY
AND
BEARING PRELOAD
M-9

AXLE
SHAFT INSTALLATION
M-ll
FRONT AXLE INSTALLATION........
.M-l2
Turning
Angle Adjustment . .M-14

Steering
Tie Rod and
Beilcrank
M-l3

2-WHEEL DRIVE FRONT AXLE
M-15
Removal
of Solid
Front
Axle M-l6

Steering
Knuckle
Service M-l7

Steering
Knuckle
Pin Replacement. ......M-l8

SERVICE
DIAGNOSIS
M-19

AXLE
SPECIFICATIONS.
M-20

caster
of the front
wheels
is preset.
Camber
cannot
be altered but caster can be adjusted by installing

caster
shims
between
the axle pad and the springs.

For
information on the steering
geometry
see
"Steering
Section."

Service
procedures given in this section include
the removal, installation, disassembly and assembly
of the Model
27AF
front axle assembly, the axle
shafts, steering knuckles, and
universal
joints.

Note:
All service replacement axle assemblies are
shipped from the factory without lubricant in the
differential.
Lubricant
must be added; use grade

and
quantity as specified in the lubrication chart (Section B).

M-3.
Maintenance Requirements

A
spring-loaded breather is located on the top of
the differential housing.
Each
time the differential
lubricant
is checked, the breather should be