cooling JEEP CJ 1953 User Guide

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

'Jeep'
UNIVERSAL SERIES
SERVICE
MANUAL

Dl

DAUNTLESS
V-6
ENGINE
Contents

SUBJECT
PAR.
SUBJEC

GENERAL
.... . . Dl-1 Oil Pump Cl(
ENGINE DESCRIPTION
D1-2

Engine
Mounts Dl-3

ENGINE REMOVAL
Dl-4
ENGINE DISASSEMBLY
Dl-5
Alternator
and Fan Belt Dl-11
Camshaft
.... Dl-26
Cooling Fan and Water Pump.
......
.Dl-12
Crankshaft
Front Oil Seal .Dl-21

Crankshaft
Pulley D1-17
Crankshaft
Vibration Damper Dl-18

Cylinder
Head Assembly Dl-24

Distributor
Dl-9
Exhaust
Manifold .Dl-8

Flywheel
Dl-28

Flywheel
Housing and
Clutch
Dl-27
Fuel
Pump. ... . .Dl-10
Intake
Manifold and
Carburetor
Assembly.
.............
.Dl-7

Main
Bearing and Crankshaft. Dl-32 Mounting Engine on Engine Stand. . . . .Dl-6

Oil
Dipstick. Dl-16
Oil
Filter
Dl-13
Oil
Pan.. ...
.......
.Dl-29
Oil
Pressure Sending Unit Dl-15

Oil
Pump Dl-19
Oil
Pump Intake Pipe and Screen Dl-30
Piston and Rod Assembly. Dl-31
Push
Rod and Valve
Lifter.
.Dl-25
Rocker
Arm Cover Dl-23
Starter
Motor Dl-14

Timing
Chain
and Sprocket Dl-22
Timing
Chain
Cover Dl-20

ENGINE CLEANING, INSPECTION AND REPAIR
. . ... .Dl-33
Camshaft
Cleaning and Inspection Dl-55
Connecting Rod Bearing Inspection
and
Fitting .Dl-49

Crankshaft
Cleaning Dl-38
Crankshaft
Inspection and Repair Dl-39
Crankshaft
Main Bearing Cleaning
and
Inspection Dl-41

Crankshaft
Main Bearings. Dl-40

Crankshaft
Pulley Inspection. Dl-70
Crankshaft
Vibration Damper Inspection. D1-69

Cylinder
Block .Dl-34
Cylinder
Block Cleaning Dl-35
Cylinder
Block Inspection Dl-36

Cylinder
Block Repair. .Dl-37
Cylinder
Head and Valve Repair .Dl-63

Cylinder
Head and Valve Cleaning
and
Inspection.. . .Dl-62

Flywheel
Cleaning and Inspection Dl-52

Flywheel
Housing Cleaning
and
Inspection Dl-54

Hydraulic
Valve
Lifter
Leakdown Test. .Dl-57
Main
Bearing Fitting or

Shim
Stock Dl-42, Dl-43

Oil
Pan Cleaning and Inspection .Dl-51
PAR.
and
Inspection. .... .Dl-68

Oil
Pump Intake and Screen Cleaning. . .Dl-50
Piston and Rod Assembly.
...........
.Dl-48
Piston and Rod Cleaning and Inspection.D1-45
Piston and Rod Disassembly Dl-44
Piston Fitting Dl-46
Piston Ring Fitting. .Dl-47

Ring
Gear
Replacement. .Dl-53
Rocker
Arm Assembly. Dl-60
Rocker
Arm Cleaning and Inspection. . .Dl-59

Rocker
Arm Cover Cleaning

and
Inspection D1-65

Rocker
Arm Disassembly .Dl-58
Timing
Chain
and Sprocket Inspection. . .Dl-66

Timing
Chain
Cover Cleaning

and
Inspection.. . Dl-67

Valve
Installation D1-64
Valve
Lifter
and Push Rod

Cleaning
and Inspection. . Dl-56

Valve
Removal Dl-61

ENGINE REASSEMBLY
Dl-71
Alternator
and Fan Belt Dl-96

Camshaft
Dl-80
Clutch
and Flywheel Housing Dl-79
Cooling Fan.. . .Dl-95
Crankshaft
End Play Check. . Dl-74

Crankshaft
Front Oil Seal Dl-85
Crankshaft
Pulley Dl-89
Crankshaft
Vibration Damper Dl-88
Cylinder
Block and Crankshaft
Rear
Oil Seals Dl-72

Cylinder
Head Assembly .Dl-82

Distributor
Dl-99

Exhaust
Manifold Dl-98
Flywheel
.Dl-78
Fuel
Pump.. .. . Dl-97
Intake
Manifold and Carburetor Assembly Dl-101

Main
Bearing and
Crankshaft
Installation
.
Dl-73

Oil
Filter
Dl-93
Oil
Level
Dipstick Dl-90

Oil
Pan Dl-77
Oil
Pressure Sending Unit Dl-91

Oil
Pump.. .Dl-87
Oil
Pump Intake and Screen Assembly. .Dl-76
Piston and Rod Installation Dl-75

Rocker
Arm Cover. Dl-83

Spark
Plugs.. Dl-100
Starter
Motor Dl-92
Timing
Chain
and Sprocket.
..........
.Dl-84

Timing
Chain
Cover Dl-86
Valve
Lifter
and Push Rod Dl-81

Water
Pump. Dl-94

ENGINE INSTALLATION
Dl-102

FINAL
IN-VEHICLE
ADJUSTMENTS.
D1-103

SERVICE
DIAGNOSIS
Dl-104
ENGINE SPECIFICATIONS
. .Dl-105 75

'Jeep*
UNIVERSAL SERIES SERVICE
MANUAL

Dl

12710

FIG.
D1
-3—HYDRAULIC VALVE
LIFTER
ASSEMBLY, CROSS-SECTIONAL VIEW
1—
Snap
Ring
6—Ball Retainer

2— Rod
Seat
7—Plunger Spring

3—
Oil
Inlets
8—Lifter
Body

4—
Plunger
9—Bronzed
Cap
5— Feed
Hole
sages
in the block and cylinder head.

The
water cooled system is pressurized to provide efficient
engine
cooling. It consists of a centrifugal-
type water pump, mounted on the timing chain cover, and is driven by the
engine
fan pulley. The
pump provides coolant flow equally to both
cylin­
der banks under control of a thermostat. Coolant
flow is around the cylinders and through the
cylinder
head to dispel the heat of combustion in
the engine.

Dl-3.
Engine Mounts

The
engine-transmission unit is mounted to the chassis at three points by rubber pads. The two
front mounts are bolted to the
engine
cylinder
block and the frame members. These mounts sup­ port most of the
engine
weight, and absorb
vibra­

tion which would otherwise be caused by changes
in
engine
output torque. The single
rear
mount is
placed
between
the transmission and the trans­ mission support. It supports part of the engine'

and
transmission weight, and locates the
rear
of
the
engine
with respect to the centerline of the
vehicle.

Dl-4. ENGINE REMOVAL
To
remove the
engine
from the vehicle follow the
procedurers listed below:

a.
Remove hood. b. Disconnect battery cables from battery and
engine. c. Remove air cleaner.

d.
Drain
coolant from radiator and engine.
e.
Drain
engine
oil.
f. Disconnect alternator wiring harness from con­ nector at regulator.

cj.
Disconnect the fuel evaporative purge line con­ nected to the
P.C.V.
valve.

h.
Disconnect upper and lower radiator
hoses
from
the engine.

i.
Remove right and left radiator support
bars,

j.
Remove radiator from the vehicle.

k.
Disconnect
engine
wiring harnesses from con­
nectors located on
engine
firewall.
I.
On
engines
equipped with exhaust emission con­

trol,
remove the air pump, air distribution manifold,

and
anti-backfire (gulp) valve. See Section F2 for
procedure.

m.
Disconnect battery cable and wiring from en­

gine
starter assembly.

n.
Remove
engine
starter assembly from engine,

o.
Disconnect
engine
fuel
hoses
from fuel lines at

right
frame
rail,
p. Plug fuel lines.

q.
Disconnect choke cable from carburetor and cable support bracket mounted on engine,
r.
Disconnect exhaust pipes from right and left

engine
manifolds.
s. Place
jack
under transmission and support trans­
mission weight.
f. Remove
bolts
securing
engine
to front motor mounts.

u.
Attach suitable sling to
engine
lifting
eyes
and,
using hoist, support
engine
weight.
v. Remove
bolts
securing
engine
to flywheel housing.
w. Raise
engine
slightly and slide
engine
forward
to remove transmission main shaft from clutch plate spline.

Note:
Engine and transmission must be raised
slightly to release the main shaft from the clutch
plate while sliding the
engine
forward.
x. When
engine
is free of transmission shaft raise

engine
and remove from vehicle,
y. Place
engine
on suitable blocking or
engine
stand and remove sling from engine.

Dl-5.
ENGINE DISASSEMBLY

Engine
disassembly is presented in the sequence to be followed when the
engine
is to be completely
overhauled after removal from the vehicle. Some of the operations of the procedure are also appli­cable separately with the
engine
in the vehicle,
provided that wherever necessary the part of the
engine
to be worked on is first made accessible by removal of
engine
accessories or other parts.

When
the disassembly operations are performed
with
the
engine
out of the vehicle, it is assumed,
in
this procedure, that all of the accessories have
been removed
prior
to starting the disassembly and
the oil has been drained.

Dl

DAUNTLESS
V-6
ENGINE
In
addition to the instructions covering operations
for disassembling the
engine
out of the vehicle, special instructions are given to cover different
operations required when disassembly is
done
with
the
engine
installed.

During
disassembly operations, the
engine
should be mounted in a suitable
engine
repair stand.

Where
practicable, modify or adapt an existing re­

pair
stand as necessary to accommodate the
engine.
If
an
engine
repair stand is not used, take care to

perform
disassembly operations in a manner that
will
protect personnel against an accident and the
engine
and its parts against damage.

Dl-6.
Mounting Engine
On
Engine Stand

Refer
to Fig. Dl-4.
a.
With
the
engine
supported by a hoist, remove
the clutch housing and clutch. Match
mark
the flywheel and the clutch cover before disassembly to assure proper reassembly.
b. Position the
engine
on the
engine
stand.
c. Release
some
tension of the hoist cables and secure
engine
to stand.

d.
Make sure the position lock on the
engine
stand
is tight to prevent the
engine
from accidentally
inverting.

e.
Release the hoist cables.
FIG.
D1
-4—ENGINE
MOUNTED
ON
STAND

1—
Spacer
J-8690-6
A—Bolt,
i/2-NC
x 3i/2"

2—
Bolt,
3/a-NC
x 4*/2" 5—Adapter 21316-J 3—
Engine
Mounting Stand
Dl-7.
Remove Intake Manifold
and

Carburetor Assembly

Disconnect crankcase vent
hose,
distributor vacuum

hose,
and fuel line from carburetor. Disconnect two distributor leads from ignition coil. Disconnect

wiring
harness from coolant temperature sending

unit.
Remove ten cap
bolts
which attach intake
manifold to cylinder heads. Remove intake mani­
fold assembly and gaskets from
engine.

Dl-8. Remove Exhaust Manifold
The
engine
has two exhaust manifolds. Remove five attaching screws, one nut, and exhaust mani­
fold from each cylinder head.

Dl-9.
Remove Distributor

Disconnect vacuum
hose
and wiring harness from

distributor.
Disconnect spark plug cables from
spark
plugs. Remove sparks plugs from
engine.
Pull

spark
plug cable retainers from brackets on rocker

arm
covers. Remove mounting screw, retainer

bracket,
and distributor from timing chain cover.
If
timing chain and sprockets are not to be re­
moved from
engine,
note
position of distributor
rotor so that it can be installed in identical position.

Dl-10. Remove
Fuel Pump
Disconnect output fuel line from fuel pump. Re­
move
two mounting bolts, fuel pump, and gasket

from
timing chain cover.

Dl-11.
Remove Alternator
and Fan
Belt

Disconnect wiring harness from alternator. Remove nut and flat washer which fasten alternator to
adjustment bracket. Pivot alternator
inward,
to­

ward
engine
cylinder block, to relieve fan belt
tension. Remove fan belt from pulleys. Remove
two attaching screws, mounting bracket, and alter­ nator from right cylinder head of
engine.

Dl-12.
Remove Cooling
Fan and
Water Pump

Refer
to Fig. Dl-5.
Remove four cap screws, lock washers, cooling fan,

fan
hub, and fan drive pulley from flange of water
pump shaft. Remove nine attaching screws, water
pump, alternator adjustment bracket, and water pump from timing chain cover.

Dl-13.
Remove
Oil
Filter

Unscrew
oil filter from
engine
oil pump.

Dl-14.
Remove Starter Motor

Disconnect wiring harness from starter motor and
solenoid. Remove two attaching screws, starter motor, solenoid, and motor attaching bracket from

engine
flywheel housing and cylinder block.

Dl-15.
Remove
Oil
Pressure Sending Unit

Disconnect wiring harness from oil pressure send­
ing unit. Remove oil pressure sending unit from

engine
cylinder block.

Dl-16.
Remove
Oil
Dipstick

Withdraw
and remove oil level dipstick and dip­

stick
tube
from
engine
cylinder block.

Dl-17.
Remove Crankshaft Pulley

Remove six attaching screws and crankshaft pulley

from
crankshaft vibration damper. 80

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

Dl

13296

FIG.
Dl-5—ENGINE
LUBRICATION
AND
COOLING
PARTS

1— Bolt and
Lock
Washer
2—
Fan
Assembly
3—
Fan
and Alternator Belt
4—
Fan
Driven Pulley 5— Water Pump Assembly
6—
Hose
Clamp 7— Thermostat Bypass
Hose

8—Hex
Head Bolt
9— Water Outlet Elbow
10— Water Outlet Elbow Gasket
11— Thermostat
12— Water Pump Gasket
13— Impeller and Insert, Water Pump
14— Water Pump Seal 15— Dowel Pin % x Vfc"
16— Water Pump Cover
17— Bolt,
1/4-20
x 1"
18— Water Pump Shaft and Bearing
19—
Fan
Hub
20—
-Oil
Suction Pipe Gasket
21—
Oil
Suction Housing, Pipe and Flange
22— Bolt,
y4-20
x s/8"
23—
Oil
Pump Screen
24—
Oil
Dipstick
25—
Oil
Pan Gasket
26—
Oil
Pan Assembly
27—
Drain
Plug Gasket
28—
Drain
Plug 29— Screw and
Lock
Washer #6-18 x %
30—
Oil
Pump Shaft and Gear
31—
Oil
Pump Cover Gasket
32— Valve Bypass and Cover Assembly
33—
Oil
Pressure Valve 34— Valve Bypass Spring
35—
Oil
Pressure Valve Cap Gasket
36—
Oil
Pressure Valve Cap
37— Screw V4-20 x lVg"
38— Screw 1/4-20 x 1W' 39—
Fan
Driving Pulley
40— Hex. Head Bolt, x 1"
Dl-13.
Remove
Crankshaft
Vibration Damper

Refer
to Fig. Dl-6.
Remove cap screw and flat washer which attach

crankshaft
vibration damper to crankshaft. Tap

vibration
damper with a soft-headed hammer to remove it from crankshaft.

Dl-19.
Remove Oil Pump
Remove five screws, oil pump cover, and gasket

from
right side of timing chain cover. Remove
two oil pump gears.

D1-20.
Remove Timing Chain Cover

Refer
to Fig. Dl-6. Remove two
bolts
which attach oil pan to timing

chain
cover. Remove five mounting bolts, timing

chain
cover, and gasket from cylinder block of
engine.

Note:
Water pump must be removed from timing

chain
cover before timing chain cover is removed

from
cylinder block.
Dl-21.
Remove Crankshaft Front
Oil
Seal

Refer
to Fig. Dl-6.
Use timing cover aligner and oil seal remover
tool
J-22248 to remove oil seal.

Dl-22.
Remove Timing Chain
and
Spocket

a.
Temporarily install vibration damper (Fig.

Dl-6)
bolt and washer in end of crankshaft.
Turn

crankshaft
so sprockets are positioned with index

marks
aligned as shown in Fig. Dl-7.
This
will

make it easier to install parts. Remove vibration
damper bolt and washer; rap the wrench handle
sharply
to start the bolt without changing position
of sprockets.

Note:
It is not necessary to remove timing chain
dampers unless they are worn or damaged and

require
replacement.
b. Remove front crankshaft oil slinger.
c. Remove bolt and special washer which retain
camshaft distributor drive gear and fuel pump
eccentric at forward end of camshaft. Remove gear
and
eccentric from camshaft. 81

Dl
DAUNTLESS
V-6
ENGINE

FIG.
Dl-41—WATER
PUMP
AND
TIMING CHAIN COVER BOLT LOCATION
Cover
Bolts

alternately and evenly 8 to 12 lb-ft. [1,10 a 1,66

kg-m.].

Dl-88.
Install
Crankshaft
Vibration
Damper

a.
Lubricate
the vibration damper hub
before
in­
stallation to prevent
damage
to the crankshaft
front oil seal during installation and when the

engine
is first started.
b.
Install
the vibration damper on the crankshaft.
Secure it with its attaching flat washer and screw.

Torque
the screw to a minimum of 140 lb-ft.
[19,35
kg-m.].

Dl-89.
Install
Crankshaft Pulley
Secure the crankshaft pulley to the crankshaft

vibration
damper with six screws. Torque screws 18 to 25 lb-ft. [2,5 a 3,4 kg-m.].

Dl-90.
Install
Oil
Level
Dipstick

Insert
oil level dipstick
into
the dipstick tube.

Dl-91.
Install
Oil
Pressure Sending Unit

Install
oil pressure sending unit in cylinder block.
Connect electrical wiring harness to unit.

Dl-92.
Install Starting Motor

Secure starting motor and
solenoid
assembly to
the flywheel housing and cylinder block with two attaching screws. Torque screw, which attaches this
assembly to the flywheel housing, 30 to 40 lb-ft. [4,1 a 5,5 kg-m.]. Torque screw, which attaches

bracket
to cylinder block, 10 to 12 lb-ft. [1,4 a 1,7 kg-m.].
Dl-93.
Install
Oil
Filter

Install
a new oil filter
element
at oil filter nipple,
at
left
side
of timing chain cover. Torque 10 to 15 lb-ft. [1,38 a 2,07 kg-m.].

D1-94. Install Water Pump
Be
certain that mating surfaces of the water pump

and
timing chain cover are clean.
Install
a new
gasket
on the pump flange. Secure the pump and
alternator adjustment bracket to the cover with
nine attaching bolts. Torque
bolts
6 to 8 lb-ft. [0,83 a 1,10 kg-m.]. Refer to Fig. Dl-41.

D1-9S.
Install
Cooling Fan
Secure the cooling fan, fan hub, and fan drive
pulley to the water pump shaft
flange
with four
attaching screws. Torque screws 17 to 23 lb-ft. [2,35 a 3,18 kg-m.].

Dl-96.
Install
Alternator
and Fan
Belt

Mount the alternator and bracket assembly on
right
cylinder head with two attaching screws.

Torque
screws 30 to 40 lb-ft. [4,1 a 5,5 kg-m.].

Fasten
the alternator
loosely
to its adjustment
bracket
with attaching flat washer and nut.
Install

the fan
belt
on its pulleys. Pivot the alternator
outward,
away from cylinder block, to apply fan

belt
tension. Adjust fan
belt
tension to 80 lb. [36,2 kg.];
tighten
alternator-to-adjustment bracket
nut to secure adjustment
setting.
Connect wiring
harness to alternator.

Dl-97.
Install
Fuel Pump

Install
two mounting
bolts
and new
gasket
on

flange
of fuel pump. Secure pump to timing chain cover with screws; torque screws 17 to 23 lb-ft. [2,35 a 3,8 kg-m.]. Connect
output
fuel line to
pump.

Dl-98.
Install Exhaust Manifold

Secure each of two exhaust manifolds to corre­
sponding cylinder head with five attaching screws,
and
one nut. Torque screws and nut 15 to 20 lb-ft. [2,07 a 2,8 kg-m.]. See Fig. Dl-42.

Dl-99.
Install Distributor

Insert
distributor drive gear
into
distributor mount-
FIG.
Dl-42—EXHAUST
MANIFOLD INSTALLATION

1—Torque
Bolts—15
to 20
lb-ft.
[2,07 a 2,8
kg-m.]

102

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

Dl
Dl-104.
SERVICE
DIAGNOSIS

Poor Fuel Economy
Ignition Timing Late or Spark Advance Inoperative

Carburetor
Float Setting Too High
Accelerator Pump Improperly Adjusted
Fuel
Pump Pressure High

Fuel
Line
Leakage

Fuel
Pump Diaphragm Leakage
Cylinder
Compression Low
Valves Do Not Seat Properly
Spark
Plugs
Defective

Spark
Plug Cables
Defective

Ignition
Coil
or Capacitor
Defective

Carburetor
Air Cleaner Dirty

Brakes
Drag
Wheel Alignment Incorrect

Tire
Pressure Incorrect Odometer Inaccurate

Fuel
Tank
Cap Clogged or
Defective

Muffler or Exhaust Pipe Clogged or Bent

Lack
of
Power
Cylinder
Compression Low
Ingitdon Timing Late

Carburetor
or
Fuel
Pump Clogged or
Defective

Fuel
Lines Clogged
Air
Cleaner Restricted
Engine Temperature High Valves Do Not Seat Property

Valve
Timing Late Intake Manifold or Cylinder Head
Gasket Leaks
Muffler or Exhaust Pipe Clogged or Bent
Spark
Plugs Dirty or
Defective

Breaker
Point Gap Incorrect
Breaker
Points
Defective
Ignition
Coil
or Capacitor
Defective

Electrical
Connection Loose
Broken
Valve Spring

Broken
Piston Ring or Piston
Cylinder
Head Gasket
Defective

Distributor Cap Cracked

Low
Compression
Valves Not Seating Properly Piston Rings Seal Poorly
Valve
Spring Weak or Broken
Cylinder
Scored or Worn
Piston Clearance Too Great

Cylinder
Head Gasket Leaks

Burned
Valves and
Seats
Valves Stick or Are Too Loose in Guides
Valve
Timing Incorrect

Valve
Head and Seat Have Excessive Carbon
Engine Overheats

Valve
Spring Weak or Broken

Valve
Lifter Seized or Collapsed
Exhaust
System Clogged
Valves Sticking

Valve
Stem Warped

Valve
Stem Carbonized or Scored

Valve
Stem Clearance Insufficient in Guide

Valve
Spring Weak or Broken

Valve
Spring Distorted
Oil
Contaminated

Overheating
Cooling System Inoperative
Thermostat Inoperative Ignition Timing Incorrect

Valve
Timing Incorrect
Carbon
Accumulation Excessive

Fan
Belt Loose
Muffler or Exhaust Pipe Clogged or Bent

Oil
System Failure
Piston Rings Worn or Scored
Popping,
Spitting,
Detonation
Ignition Timing Incorrect

Carburetion
Improper

Carbon
Deposit
in Combustion
Chambers Excessive
Valves Not Seating Properly
Valve
Spring Broken
Spark
Plug Electrodes Burned
Water or Dirt in
Fuel
Fuel
Line
Clogged
Valve
Timing Incorrect

Excessive
Oil
Consumption
Piston Rings Stuck in Grooves, Weak,
Worn,
Broken, or Incorrectly Fitted

Crankshaft
Main Bearings or
Connecting Rod Bearings Have
Excessive Clearance
Gaskets or Oil Seals
Leak

Cylinder
Bores Worn, Scored,
Out-of-Round or Tapered
Pistons Have Too Great Clearance to Cylinder Bores
Connecting Rods Misaligned High Road Speed
High Temperature

Crankcase
Ventilation System Inoperative
Bearing Failure
Crankshaft
Bearing Journal Rough or Out-of-Round

Oil
Level Low
Oil
Leakage

Oil
Dirty
Oil
Pressure Low or Lacking
(Oil
Pump Failure)

Drilled
Passages
in Crankshaft or
Crankcase
Clogged

Oil
Screen Dirty
Connecting Rod Bent 105

E

FUEL
SYSTEM
Note:
Do not remove pressed-in parts such as
nozzle, pump jet, or antipercolator air bleed.

j.
Remove body flange attaching screws, body flange assembly, and gasket.

k.
Remove idle-adjustment screw, spring, idle

port
rivet, throttle lever assembly, washer, fast
idle arm, throttle plate screws, throttle plate, and throttle shaft.
1. Remove throttle shaft seal by prying out seal

retainer.

Note:
Do not remove pressed-in vacuum passage

orifice.

m.
Remove choke valve screws and choke valve.

Unhook
choke spring and slide shaft from housing,
n.
Wash all parts in carburetor cleaning solution

and
blow out passages with compressed air. Do not immerse diaphragm or seals in cleaning solution.

Inspect
all parts for wear or damage. Always use
new gaskets when reassembling.

E-22.
Carburetor
Reassembly

•
Refer to Fig. E-13.

To
expedite
reassembly, it is advisable to group all

related
parts by the circuit to which they belong.

a.
Install
throttle shaft seal and retainer in flange casting.

b.
Install
fast-idle
arm,
washer, and lever assembly
on throttle shaft. Slide shaft into place and install throttle valve.

c.
Install
idle port rivet plug and idle adjusting

screw
and spring.

d.
Attach flange assembly to body casting. Use new gasket.
e.
Install
low-speed jet assembly.
f.
Early
production models install pump intake
strainer
in pump diaphragm housing and carefully
press into recess.

Note:
If strainer is even slightly damaged, a new
one must be installed.
g.
Install
pump diaphragm assembly in diaphragm housing.
Then,
install pump diaphragm spring
(lower)
and retainer.

h.
Install
pump lifter
link,
metering rod
arm,
upper
pump spring, and retainer.

I.
Install
metering rod jet.

Note:
No gasket is used with this jet.

j.
Install
diaphragm housing attaching screws in
the diaphragm housing, making sure that the

edges
of the diaphragm are not wrinkled.
Lower

into place and tighten screws evenly and securely,
k.
Install
throttle shaft seal, dust seal washer, and
shaft seal spring.

I.
Install
pump connector
link
in the throttle arm
assembly.
Install
throttle shaft arm assembly on
throttle shaft guiding connector
link
in pump lifter

link
hole.
CAUTION:
Linkage
must not bind in any throttle
position. If binding occurs,
loosen
clamp screw in
throttle arm, adjust slightly, then retighten screw.

m.
Install
pump check disc, disc retainer, and lock

ring.

n.
Install
metering rod and pin spring. Connect
metering rod spring.
o.
Check
and if necessary correct meter ing rod adjustment. Follow procedure of
Par.
E-16.
p.
Install
needle
seat and gasket assembly, needle,
float
and
float pin. The
stop
shoulder on the float
pin
must be on the side away from the bore of
the carburetor.

q.
Set float level to specifications. Follow pro­ cedure of
Par.
E-12.

r.
Install
air horn gasket and air horn assembly.

Install
attaching screws, lock washers, and choke
tube clamp assembly. Tighten center screws first,
s. Slide choke shaft and lever assembly into place
and
connect choke lever
spring.
Install
choke valve.
Center
the valve by tapping lightly, then hold in
place with fingers when tightening screws,
t.
Install
fast-idle connector rod with
offset
portion
of rod on top and pin spring on outside.
Install
fast-idle connecting rod spring.

E-23.
Correcting Acceleration
Flat
Spot

Early
production
Carburetor
Models 938-S, 938-
SA,
938-SC

Inasmuch
as a flat
spot
on acceleration or low speed
stumble can
come
from causes other than
car­

buretor
malfunction, it is recommended that
engine

tuning be thoroughly checked before attempting
any
actual carburetor work. Make sure that
ignition, compression, and timing are correct and
that fuel pump is supplying enough gas. Also, the F-head
engine
employs a water-heated intake

manifold.
Proper vaporization of the fuel depends
on correct intake manifold temperature. Since this
temperature is controlled by the cooling system
thermostat, include an operational check of the
thermostat when diagnosing the stumble. Operating
temperatures consistently below
155°F.
can cause stumble.

If
the stumble persists, a
YF-938-S,
YF-938-SA,

or
YF-938-SC
carburetor can be converted to a
YF-938-SD
carburetor by installing Special Kit
924161, consisting of a pump discharge check
needle, a metering rod, and a metering rod jet. If this kit is installed, the pump discharge check

needle
replaces the original
ball,
weight, and re­

tainer
and the small wire-type retainer used with
the
ball
check assembly must not be reinstalled.

When
installing the kit, check the size of the pump discharge jet, No. 2, Fig. E-14.
Early
production
YF-938S
and
YF-938SA
carburetors have a .025" [0,635 mm.] jet installed. If the carburetor being
converted has a .025" jet it must be opened up to .031" [0,787 mm.] by running a No. 68
drill
through
the jet as shown in
Fig.
E-14.
The jet must be drilled
as it is a pressed in part and cannot be replaced.
Upon
completing the installation of the conversion

kit,
mark
or tag the carburetor to indicate that it
is a
YF-938SD.
118

'Jeep*
UNIVERSAL SERIES SERVICE
MANUAL

F EXHAUST SYSTEM

Contents

SUBJECT
PAR.

GENERAL
.F-l Dauntless V-6 Engine Exhaust System....
F-3

Hurricane
F4 Engine Exhaust System....
F-2

MAINTENANCE
REQUIREMENTS
F-4

EXHAUST SYSTEM SERVICING
F-5
SUBJECT
PAR.

Exhaust
Manifold Installation. .F-6
Exhaust
Pipe(s) Replacement F-8

Heat
Control Valve Replacement F-7

Muffler
Replacement F-9
Tail
Pipe Replacement F-10

EXHAUST SYSTEM SPECIFICATIONS.
.
F-11

F-L
GENERAL
The
major components of the exhaust system (Figs.
F-l,
F-2 and F-3) are the exhaust manifold(s), ex­
haust pipe(s), muffler and tail pipe. Differences in
the exhaust system occur depending on whether the vehicle is equipped with the Hurricane F4 or
Dauntless V-6 engine.

Note:
For service information on exhaust emission
control systems, refer to Section Fl and F2 of this

manual.
F-2. Hurricane
F4 Engine Exhaust System

On
the Hurricane F4 engine, the exhaust and in­
take manifolds are separate units. The intake mani­
fold is cast as an integral part of the cylinder head

and
is completely water jacketed.
This
construction

transfers
heat from the cooling system to the in­
take riser and assists in vaporizing the fuel when
the
engine
is cold.

With
this construction, there is no heat control
valve on the
engine
and the only function of the exhaust manifold is to gather and direct the exhaust
FIG.
F-l—HURRICANE F4 ENGINE EXHAUST
SYSTEM
—
EARLY
MODEL
1—
Exhaust
Pipe
2—
Clamp

3—
Exhaust
Pipe Extension
4—
Clamp

5— Tail
Pipe 6—
Muffler
7—
Clamp

8—
Support
Strap

9—Bolt

10—Support
Strap
11—Bracket

12—
Insulator

13—
Bracket

14—
Nut
and
Lockwasher
15—
Washer

16—Bolt

17—
Gasket

18—
Bolt
19— Nut
137

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

F2

FIG.
F2-4—HOT
AIR
DOOR
OPEN

1—
Linkage

2— Motor
3—
Air
Cleaner
4— Sensor 5—
Temp
Sensing Spring
6—
Air
Bleed Valve 7—
Hot
Air Pipe 8—
Diaphragm
Spring
9—
Diaphragm

10—
Control
Damper
11—
Air
Inlet
12—
Vacuum
Chamber
13—
Snorkel
Tube
To
perform the thermometer check, proceed as
follows:
1. Start
test
with air cleaner temperature below
85°
F.
[29.4°
C.]. If
engine
has been run recently, allow it to cool down. While
engine

is cooling, remove air cleaner cover and

install
a temperature
gage
next to sensor.

Reinstall
air cleaner cover. Do not install wing nut. Let car stand idle for
V2
hour or
more before proceeding to
step
2.
2. Start engine.
Cold
air door should
close
im­ mediately if
engine
is cool enough. When cold air door starts to open (in a few min­
utes), remove air cleaner cover and read
temperature
gage.
It must read 115° F.
[46°
C]
±20°.
3.
If cold air door
does
not start to open at
temperature indicated, temperature sensor is
defective and must be replaced.

F2-5.
Carburetor Air
Cleaner—Dry
Type

Every
24,000
miles
[38,400
km.] (or more fre­
quently in dusty territory) replace the air cleaner element. To do this, remove the wing nut and cover

from
the air cleaner housing.
Lift
out the air cleaner
element. Wipe the inside of the housing clean.
Service
the positive crankcase valve filler as out­
lined in paragraph F2-6. Make sure the air cleaner gasket is in
good
condition and properly located
on the carburetor flange.
Install
a new element, the cover and wing nut. Tighten the wing nut by hand.

Tighten
to make sure the air cleaner remains 153