1953 JEEP DJ Service Manual

'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

F

EXHAUST
SYSTEM
12844

FIG.
F-2—DAUNTLESS
V-6
ENGINE
EXHAUST
SYSTEM
—
EARLY
MODEL
1—
Right
Exhaust
Pipe
19—Lockwasher

2—Tall
Pipe 20—Bolt

3—
Bolt
21—Bracket

4—
Bolt
22—Insulator

5—
Muffler
23—Nut 6—
Exhaust
Pipe
Extension
24—Bolt
7—
Crossover
Exhaust
Pipe
25—Clamp

8—
Bracket
26—U-Bolt 9—
Lockwasher
27—Saddle

10—
Nut
28—U-Bolt
11—
Saddle
29—Saddle

12—
Washer
30—Insulator

13—Bolt
31—U-Bolt
14—
Bracket
32—Nut

15—
Reinforcement
3
3—Lockwasher

16—
Nut
34—U-Bolt

17—
Lockwasher
35—Saddle

18—
Nut

gases
into the exhaust pipe.

When
assembling the manifold, to the cylinder
block
(Fig.
F-4)
new gaskets should be installed
and
the nuts drawn up evenly until they are tight
to avoid leakage. Torque manifold nuts to 29-35 lb-ft [4,0 a 4,84 kg-m.].

F-3.
Dauntless
¥-6
Engine
Exhaust System

Each
of two cylinder banks of a Dauntless V-6 engine has an exhaust manifold. On late production engines the right exhaust manifold is equipped

with
a heat collector manifold which supplies heated air to the air cleaner. See Fig. F-5.
Each
cylinder
exhausts through its own individual port
into a branch of its exhaust manifold. These
branches
conduct exhaust
gases
into the main mani­
fold branch which connects the exhaust pipe to
the muffler. A thermally-actuated heat control valve is located at the
rear
of the right exhaust

manifold.
This
valve has a bimetal thermostatic
spring
which holds it closed when the engine is

cold.

In
closed position, the valve deflects exhaust
gases

upward
through a passage in the intake manifold to the left exhaust manifold.
This
aids in vaporizing

fuel,
speeds
engine warm-up, and reduces oil
dilution.

Since
the valve plate is offset-mounted, the valve

will
be forced partially open at higher engine speed
and
load.
This
prevents excessive back pressure. 138

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

©

1

1

©-
IT

T"

I

FIG.
F-3—EXHAUST SYSTEM —
LATE
MODEL

A—Hurricane
F4 Engine B—Dauntless V6 Engine
1—
Exhaust
Pipe F4 Engine

2—
Exhaust
Pipe
Extension
— F4 Engine

3—
Muffler

4—
Tail
Pipe
5—
Right
Exhaust
Pipe V6 Engine

As
the
engine
increasingly warms up the thermo­ static spring tension decreases until it allows the
valve to open completely.
That
restores usual ex­ haust operation.

As
part of regular tune-up procedure the valve operation should be checked. Valve plate should
move
freely, without binding or excessive play.
If
necessary to replace the heat control valve (Fig.

F-6),
disconnect exhaust pipe from valve. Remove
two attaching
bolts
and valve from exhaust mani­
fold. Fasten replacement valve to manifold with two bolts. Torque
bolts
15 to 20 lb-ft [2,1 a 2,8

kg-m.].
No gasket is required
between
valve and manifold. Connect exhaust pipe to valve.

To
remove the exhaust manifolds, disconnect the heat riser
tubes
and the exhaust pipe or the heat
control valve from the manifold. Remove the cap screws that secure the manifold to the cylinder
head; remove the manifold. 6—
Left
Exhaust
Pipe V6 Engine
7—
Exhaust
Pipe
Clamp

8—
Front
and
Rear
Muffler
Clamp

9—
Tail
Pipe
Clamp

Install
the exhaust manifold(s) and torque cap
screws 15 to 20 lb-ft. [2,07 a 2,8 kg-m.]. Refer
to Fig. Dl-42.
F-4.
MAINTENANCE REQUIREMENTS

The
exhaust system must be free of exhaust gas leaks and vibration. The system should be checked periodically and all
loose
or broken hanger supports
should be tightened or replaced. In addition, check
for
dents
or restrictions in the tail pipe, exhaust pipe, or muffler as such restrictions can cause faulty

engine
performance. Exhaust gas leaks in the sys­
tem are dangerous as well as being noisy.
Occasionally,
vibrations may be the result of mis­
aligned hanger supports. These vibrations can be
eliminated by loosening the clamps and changing position so that the exhaust pipe, muffler, and tail
pipe
will
be in proper alignment, free of contact

with
the frame or body. 139

F
EXHAUST SYSTEM

FIG.
F-4—EXHAUST MANIFOLD-HURRICANE
F4
ENGINE

1—
Stud
Nut
2—
End
Gasket
3—
Stud

4—
Manifold
5—
Center
Gasket
6—
Stud

7—
Gasket

F-5.
EXHAUST SYSTEM SERVICING
The
following paragraphs (F-6 through F-10)
describe the service that may be performed on the
exhaust system on the 'Jeep' vehicles.

F-6.
Exhaust Manifold Installation

When
assembling the exhaust manifold to the cylin­ der block on the F4 engine, install a new gasket. Before installing the manifold, have the mating
sur­

faces clean and smooth. If stud threads on the
Hur­

ricane
F4
engine
are damaged, correct the condition

with
a thread die or replace the studs.

When
installing the exhaust manifold, there should
be no bind
between
the manifold studs and stud
holes. Where such a condition is experienced, the stud
hole
at either end of the manifold must be
enlarged only enough to relieve the binding con­
dition.

Torque
exhaust manifold attaching nuts 29 to 35 lb-ft. [4,0 a 4,8 kg-m.] on F4-134 engine, 15 to 20
lb-ft. [2,1 a 2,8 kg-m.] on V-6
engine
(as described

in
Par. C-5).
F-7.
Heat
Control Valve Replacement

Refer
to Par. F-3.

FIG.
F-5—EXHAUST MANIFOLD
-
LEFT
SIDE
V6
ENGINE
1—
Manifold

2—
Manifold
Heat Collector
J666S

14287

FIG.
F-6—HEAT CONTROL
VALVE
DAUNTLESS
V6
ENGINE
1— Weight
Forward
— Valve Open
2— Weight
Vertical
— Valve Closed 140

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

F F-8.
Exhaust
Pipe Replacement

When
replacing the exhaust pipe(s) refer to
Figs.
Fl,
F2 and
F-3.
Remove the nuts securing the ex­
haust pipe(s) to the exhaust manifold(s), loosen

and
disconnect mounting
clamp
(s)
as necessary, loosen clamp securing exhaust pipe to muffler and
remove exhaust pipe(s).
Note: Always use new gasket(s) between exhaust
pipe(s) and exhaust manifold(s). After installation
of exhaust pipe(s), check the exhaust system for
alignment and leaks.

F-9.
Muffler Removal and Replacement
Disconnect the support bracket and clamps on each
side of the muffler. Loosen the
tail
pipe support
clamp
bolt and
pull
the
tail
pipe to the
rear
until

it
is free of the muffler. Remove the muffler. To

install
the muffler, reverse the above
steps
and

properly
align the complete system, then tighten
connecting support brackets securely. Operate the engine and check for possible leaks.
F-10.
Tail
Pipe Removal and Replacement
Refer
to
Figs.
F-l,
F-2 and
F-3.

Disconnect the support bracket and clamps both at the
rear
of the muffler and also at outlet end of
the
tail
pipe.
Free
the
tail
pipe from the muffler. To
assemble, position
tail
pipe to the muffler and secure clamps, being careful to align the exhaust
system so it doesn't contact body or frame.
Check

system for exhaust gas leaks.

F-ll.
EXHAUST SYSTEM SPECIFICATIONS
EARLY
MODEL
HURRICANE
F4
ENGINE
EARLY
MODEL
DAUNTLESS
V-6
ENGINE

TYPE:

Muffler:
Type

Exhaust
Pipe:

Wall
Thickness

Tail
Pipe:

Crossover
Pipe
Diameter
Single

Reverse
Flow

1.625*
[4,13 cm.] .065* [1,6 ram.]

1.625*
[4,13 cm.] Single
With
Cross-Over

Reverse
Flow
2.00* [5,08 cm.] .065* [1,6 mm.]
2.00* [5,08 cm.]
2.00* [5,08 cm.] .065* [1,6 mm.]

Wall
Thickness Single
With
Cross-Over

Reverse
Flow
2.00* [5,08 cm.] .065* [1,6 mm.]
2.00* [5,08 cm.]
2.00* [5,08 cm.] .065* [1,6 mm.]

LATE
MODEL
HURRICANE
F4
ENGINE
LATE
MODEL
DAUNTLESS
V6
ENGINE

TYPE:
Muffler:

Exhaust
Pipe:
Wall
Thickness

Exhaust
Pipe Extension:

Wall
Thickness

Crossover
Pipe: Single

Reverse
Flow
2.005* [5,09 cm.]

1.755*
[4,46 cm.]

1.625*
[4,13 cm.]
.065* [1,6 mm.]

1.629*
[4,14 cm.] 2.00* [5,08 cm.] .065* [1,6 mm.] Single with
Cross-Over

Reverse
Flow
2.005* [5,09 cm.]

1.755*
[4,46 cm.]
2.00* [5,08 cm.] .065* [1,6 mm.]
2.00* [5,08 cm.] .065* [1,6 mm.]

1.753*
[4,45 cm 1

Wall
Thickness

Tail
Pipe
1.753*
[4,45 cm.] Single with
Cross-Over

Reverse
Flow
2.005* [5,09 cm.]

1.755*
[4,46 cm.]
2.00* [5,08 cm.] .065* [1,6 mm.]
2.00* [5,08 cm.] .065* [1,6 mm.]

1.753*
[4,45 cm 1 141

'Jeep'
UNIVERSAL SERIES SERVICE
MANUAL

Fl
EXHHUST
EMISSION
CONTROL
SYSTEM

Contents

HURRICANE
F4-134
ENGINE
SUBJECT
PAR.

GENERAL
Fl-1

AIR
PUMP
Fl-2

PUMP
AIR
FILTER
Fl-3

AIR
DELIVERY
MANIFOLD
Fl-4

AIR INJECTION TUBES.
Fl-5

ANTI-BACKFIRE
DIVERTER
VALVE.
.Fl-6

ENGINE
COMPONENTS
. .Fl-7
Carburetor
. .Fl-8

Distributor
........
.Fl-9
Exhaust
Manifold Fl-10

MAINTENANCE
Fl-11
Carburetor
Fl-12,
Fl-13

Distributor
Fl-14

Anti-Backfire
Diverter
Valve.
.........
.Fl-15

Check
Valve Fl-16

Fl-1. GENERAL—F4-134
Engine

The
Hurricane
F4-134
engine
Exhaust
Emission
Control
System consists of a belt driven air pump

which
directs compressed air through connecting

hoses
to a steel distribution manifold into stainless steel injection
tubes
in the exhaust port adjacent
to each exhaust valve stem.
This
air with its normal

oxygen
content, reacts with the hot but incom­
pletely burned exhaust
gases
and permits further combustion in the exhaust port or manifold.
Fl-2. AIR
PUMP

The
air injection pump is a positive displacement
vane type which is permanently lubricated and
requires
no periodic maintenance.

The
pump contains an integral relief valve which controls the air supplied to the
engine
exhaust ports

during
high speed operation to limit maximum ex­
haust system temperatures.

Fl-3. PUMP
AIR
FILTER

The
air filter attached to the pump is a replaceable
element type constructed of conventional pleated
paper
with steel end plates.

The
filter should be replaced every
12,000
miles
[19,200
km.] under normal conditions or sooner

under
adverse weather or driving conditions.

Fl-4.
AIR
DELIVERY
MANIFOLD

The
air delivery manifold, constructed of cold
rolled
steel with a zinc plating, distributes the air

from
the pump to each of the air delivery
tubes

in
a uniform manner.

A
check valve is attached to the air delivery
SUBJECT
PAR.

Air
Pump Fl-17
Carburetor
Air Cleaner Fl-18

REMOVAL PROCEDURES
.Fl-19
Air
Pump
Fl-20
Anti-Backfire
Diverter Valve Fl-21
Air
Distribution Manifold,
And
Air Injection Tubes
Fl-22

REQUIRED
EQUIPMENT
.Fl-23

REPLACEMENT
PARTS
Fl-24

WARRANTY
Fl-25

DIAGNOSIS
GUIDE
Fl-26
MAINTENANCE CHART
Fl-27

CARBURETOR SPECIFICATIONS
Fl-28

DISTRIBUTOR SPECIFICATIONS
Fl-29
SPARK PLUG
GAP
.Fl-30

manifold.
Its function is to prevent the reverse flow
of exhaust
gases
to the pump should the pump
drive
fail.
This
reverse flow would damage the air
pump and connecting
hose.

Fl-5.
AIR
INJECTION
TUBES

The
air injection
tubes
of stainless steel are inserted
into machined
bosses
of the exhaust manifold. The

tubes
project into the exhaust ports directing air
into the vicinity of the exhaust valve stem.

Fl-6.
ANTI-BACKFIRE DIVERTER VALVE

The
anti-backfire diverter valve prevents
engine
backfire
by briefly interrupting the air being in­
jected into the exhaust manifold during periods of deceleration (rapid throttle closure).

Fl-7.
ENGINE
COMPONENTS

The
following items
vary
in design or specifications

from
those
on vehicles not equipped with the Ex­
haust Emission
Control
System.

Fl-8.
Carburetor

A
carburetor with a specific flow characteristic is used for exhaust emission control.

A
carburetor dashpot is provided to control the throttle closing speed.

Fl-t.
Distributor

The
ignition distributor used with the exhaust emission system requires a different advance curve

from
that used on the F4-134
engine
prior
to the
introduction of exhaust emission systems. 143

Fl
EXHAUST EMISSION CONTROL SYSTEMS

12793

FIG.
Fl-1—HURRICANE
F4-134
ENGINE EXHAUST EMISSION CONTROL SYSTEM
1—
Anti-Backfire
Diverter
Valve

2— Air
Pump

3—
Pump
Air
Filter
Injection
Tube(s)
(Inside
Manifold)

5—Air
Delivery
Manifold
6—
Check
Valve
Ignition
timing must be set at 0 or at top dead
center.

Fl-10.
Exhaust Manifold

The
exhaust manifold is provided with a
boss
that is drilled and tapped at each cylinder to accept the

air
delivery manifold and injection tubes.

Fl-11.
MAINTENANCE

Efficient
performance of the exhaust emission con­
trol
system is dependent upon precise maintenance.
In
addition to the air pump and connecting
hoses

and
tubes, this system's efficiency is dependent
upon special carburetor calibration, distributor cen­

trifugal
advance curve and ignition timing setting

which
must be adjusted at 0 or top dead center.

Road
test
is a factory recommended optional serv­ ice every
6,000
miles
[9,600
km.] to evaluate over­

all
performance.

The
following procedure is recommended to assist
in
diagnosing performance and/or emission level
problems that are peculiar to
Exhaust
Emission

Control
System equipped vehicles.

Fl-12.
Carburetor

Check
carburetor number for proper application. (Specifications are listed at the end of this section)

Check
the dash pot and adjust as required.

Proper
carburetor idle mixture adjustment is im­
perative for
best
exhaust emission control.
The
idle adjustment should be made with the en­
gine
at normal operating temperature and air
cleaner
in place. Adjust the throttle
stop
screw to
idle the
engine
at specified RPM. All lights and accessories must be turned off.

Fl-13.
Carburetor
Idle
Setting
NOTE:
The idle mixture adjustment procedure for
the late model
YF-4941S
and
YF-6115S
Carter
Carburetor
equipped with the
External
Idle
Mix­

ture
Limiter
Cap is the same as outlined below
in
Pars.
"A"
through
"D";
however, because of the

Idle
Limiter
Cap,
the idle mixture screw
CANNOT

be adjusted in the counter-clockwise
(rich)
direc­
tion. The adjustment is made from the
rich
stop
position and the mixture screw is turned in (clock­
wise) approximately %
turn
to "Lean Best
Idle."
Refer
to Section E, Fig. E-6.

The
"Lean
Best
Idle"
method of idle setting is as follows:

a.
Any scheduled service of ignition system should
precede this adjustment. 144