1953 JEEP DJ ground clearance

GENERAL
DATA
A-8. GENERAL SPECIFICATIONS

MODEL:
CJ-3B
CJ-5,
CJ-5A
DJ-5
CJ-6,
CJ-6A
DJ-6

Engine:.
Number
of
Cylinders

Bore.
.

Stroke.
Displacement
Compression
Ratio:
Late
Production —
Standard
—
Optional.
—
Optional.

Early
Production —
Standard

—
Optional.

—
Optional.

Compression
Pressure

Horsepower
(max.
Brake)
Horsepower
(SAE)

Torque
(Max. at 2000
rpm.).
. . .

Engine:
Number
of
Cylinders

Bore

Stroke

Displacement

Compression
Ratio

Horsepower
(max.
Brake).
Horsepower
(SAE)

Torque
(Max. at 2400
rpm.).
. . .

Wheelbase

Tread
(front and
rear)
,

Height
(Over
all)
Length
(Over
all).

Width
(Over
all)

Ground
Clearance
F-4

4
3.125 [7,93 cm.]
4.375 [11,11 cm.]
134.2 cu. in. [2,20 ltr.]
7.4:1 7.8:1
6.9:1
120 to 130 psi.
[8,4 a 9,2 kg-cm2] 75 <§ 4000 rpm.
15.63
114 lb-ft. [15,8 kg-m.]

80"
[2,03 m.]
487-'f6/' [1,23 m.|
6634" [1,68 m.j

129%"
[3,30 m.]
68%"
[1,75 m.] 8" [20,32 cm.]
F-4

4
3.125 [7,93 cm.]
4.375 [11,11 cm.]
134.2 cu. in. [2,20 ltr.]
6.7:1 7.1:1
6.3:1 7.4:1
7.8:1
6.9:1
120 to 130 psi.
[8,4 a 9,2 kg-cm2] 75 @ 4000 rpm. 15.63
114 lb-ft. [15,8 kg-m.]

V-6
6
3.750" [9,525 cm.]
3.400" [8,636 cm.]
225 cu.
in.
[3,69 ltr.] 9.0:1
160 @ 4200 rpm. 33.748
235 lb-ft. [32,49 kg-m.]
81"
[2,06 m.]

48K6"
[1,23 m.]

67"
[1,70 m.]

138%"
[3,51 m.]
71%"
[1,82 m.] 8" [20,32 cm.]
F-4

4
3,125 [7.93 cm.]
4.375 [11,11 cm.]
134.2 cu. in. [2,20 ltr.]
6.7:1 7.1:1
6.3:1 7.4:1
7.8:1
6.9:1
120 to 130 psi.
[8,4 a 9,2 kg-cm2] 75 @ 4000 rpm.
15.63
114 lb-ft. [15,8 kg-m.]

V-6
6
3.750" [9,525 cm.]
3.400" [8,636 cm.]
225 cu. in. [3,69 ltr.] 9.0:1
160 @, 4200 rpm. 33 748
235 lb-ft. [32,49 kg-m.]
101"
[2,57 m.]
48^6* ]1,23 m.]

67"
[1,70 m.]
1583/4" [4,02 m.]
71%"
[1,82 m.] 8" [20,32 cm.]

CAPACITIES:
U.S.

Imperial
Metric

Fuel
Tank
(Approximate):
Early
Models

Late
Models

Cooling
System

F4
Models

V-6
Models
Note: If not equipped
with
heater deduct 10.5 gal.
16 gal.
12 qt.
10 qt.
1 qt. 8.8 gal.
13.3 gal.
10 qt. 8 qt.
.8 qt. 39,75 ltr.
60,57 ltr.
11,4 ltr. 9,5 ltr.
0,9 ltr.

CJ-
3B

CJ-5
CJ-6
DJ-5

DJ
-6

lb. kg. lb.
kg. lb.
kg. lb.
kg. lb.
kg.

WEIGHTS
(Approximate):
Gross
Vehicle
Weight
(GVW).
3500
1587 3750 1701 3900 1769 3200 1451 3200 1451

Shipping
— V6
Engine
—
'—
2240 1016 2302 1044 1900 862 2033 922

F4
Engine
2132
967 2163
981 2225
1009 1796 814 1858 842

Curb
— V6
Engine
— —

2351 1066 2413 1094 2011 912 2144 972

F4
Engine
2243
1017 2274 1031
2336 1060 1907 865 1969 893

For
Canvas
Half-Top
Model, add 35
17 38
17 38
17 38
17 38 17

For
Canvas
Full-Top
Model, add 56
25 56 25 60 27 56 25 60 27

For
Hard
Top Model, add
~~
340
154 340 154 6

C-30.
TUNE-UP
SPECIFICATIONS

ITEM

BATTERY:
Voltage
Terminal
Ground Specific Gravity:
Fully
Charged Recharge at

Load
Test, minimum:
12-Volt Battery. .

SPARK PLUGS:

Make and Model

Gap

Tightening Torque

COMPRESSION
PRESSURE CRANKING:

VALVES:
Tappet Clearance Cold:
Intake
Exhaust:
Timing (Intake Opens)

DISTRIBUTOR
Model
Dwell
Angle
Point Gap
Arm
Spring Tension

Firing
Order and Direction ....

IGNITION TIMING.
Mark
Location

ENGINE
IDLE
SPEED: W/O
Exhaust Emission Control With Exhaust Emission Control
F4
W/Dist. IAY-4401A

F4
W/Dist. IAY-4401B

FIRING
ORDER HURRICANE
F4

DAUNTLESS
V-6
12 Volts

Negative

1.260 1.225
10 Volts

AC
45 or Champion J-8 .030"
[0,762
mm.]
25 to 33
lb-ft.
[3,5 a 4,6
kg-m.]

120 to 130 psi. [8,4 a 9,2
kg-cm2]

.018"
[0,460
mm.] .016"
[0,406
mm.]
9°
BTC

PRESTOLITE

IAY-4012
IAY-4401A

IAY-4401
IAY-4401B

42°

.020"
[0,508
mm.]
17 to 20 oz.
[0,482
@
0,567
gr.]

1-3-4-2
Counterclockwise

5° BTC
0° TDC
Vibration Damper or Timing Cover
600 rpm.

1-3-4-2
650/700
rpm.

700/750
rpm. 12 Volts

Negative

1.260 1.225
10 Volts

AC
44S or Champion UJ12Y .035"
[0,889
mm.]
25 to 35
lb-ft.
[3,5 a 4,8
kg-m.]

Zero (Hydraulic Lifters)
Zero (Hydraulic Lifters)
DELCO-REMY

1110376
PRESTOLITE

IAT-4501 IAT-4502A
IAT-4502
30°

19 to 23 oz.

[0,538
@
0,652
gr.'

5°
BTC
29°
± 3°
.016"
[0,401
mm.] 17 to 22 oz.
[0,482

1-6-5-4-3-2-
Clockwise
5°
BTC
Timing Cover

650/700
rpm.
650/700
rpm.

1-6-5-4-3-2
%
0,624
gr.]

0°
TDC
NOTE:
FOR
VEHICLES
EQUIPPED WITH EXHAUST
EMISSION
CONTROL, ALSO
REFER
TO
SECTION
Fl (F4-134
ENGINE)
AND
SECTION
F2
(V6-225
ENGINE).
Co O

'Jeep*
UNIVERSAL SERIES
SERVICE
MANUAL

D
insulator
mountings attached to the frame side

rail
brackets. The
rear
of the engine-transmission
assembly is supported by a rubber insulator
mounting under the
rear
of the transmission on
the frame center cross member.
This
cross member
is bolted to the frame side
rails
so that it can be
dropped when removing the transmission or engine-

transmission
assembly. The rubber insulators allow
free side and vertical oscillation to effectively

neutralize
engine
vibration at the source.

The
rubber
insulator mountings should be inspected
for separation and deterioration by jacking the
power plant away from the frame, near the sup­
ports. Vibration cannot be effectively absorbed by
separated or worn insulators. They should be re­ placed if faulty.

D-4.
Engine
Ground
Strap

To
be sure of an
effective
ground for the electrical

circuits,
a ground strap bridges the right front

engine
support to the chassis. The connections of this strap must be kept clean and tight for proper
operation of the electrical system.

D-5. ENGINE REMOVAL

Should
the
engine
require overhauling, it is neces­

sary
to remove it from the vehicle. The following procedure covers removal of the
engine
only.

The
engine, transmission and transfer case may be
removed as a unit by removing (in addition to the following procedure) the radiator guard and the
access plates in the floor pan.

a.
Drain
the cooling system by opening the
drain
cocks at the
bottom
of the radiator and lower right
side of the cylinder block.

b.
Disconnect the battery at the positive terminal
to avoid the possibility of short
circuit.

c. Remove the air cleaner horn from the carburetor
and
disconnect the breather
hose
at the oil filler
pipe.

d.
Disconnect the carburetor choke and throttle controls by loosening the clamp
bolts
and set
screws.

e. Disconnect the fuel-tank-to-fuel-pump line at the fuel pump by unscrewing the connecting nut.
f- Plug the fuel line to prevent fuel leakage.
g. Remove the radiator and radiator grille support

rods.

h. Remove the upper and lower radiator
hoses
by
loosening the
hose
clamps and slipping the clamps
back
on the
hose.
If so equipped, remove the heater

hoses
(one to the water pump, one to the
rear
of
the cylinder head) in the same manner.

i.
Remove the four
bolts
from the fan hub and re­

move
the fan hub and fan blades.

j.
Remove the four radiator attaching screws. Re­
move
the radiator and shroud as one unit, k. Remove the starting motor cables. Remove the

starting
motor.

I.
Disconnect the wires from the alternator or
generator. Disconnect the ignition
primary
wire
at the ignition coil.
NOTE:
ON
ENGINES EQUIPPED WITH EX­

HAUST
EMISSION CONTROL, REMOVE THE
AIR
PUMP,
AIR
DISTRIBUTION
MANI­
FOLD,
AND
ANTI-BACKFIRE (DIVERTER)

VALVE.
SEE SECTION
Fl
FOR PROCEDURE.
m.
Disconnect the oil pressure and temperature
sending unit wires at the units.

n.
Disconnect the exhaust pipe at the exhaust
manifold by removing the stud nuts.

o.
Disconnect the
spark
plug cables at the plugs

and
remove the cable bracket from the rocker arm cover stud.

p.
Remove the rocker arm cover by removing the
attaching stud nuts.

q.
Attach a lifting bracket to the
engine
using
existing head bolt locations. Be sure the
bolts
selected
will
hold the
engine
with the weight

balanced.
Attach lifting bracket to a boom hoist,

or
other lifting device, and take up all slack,
r.
Remove the two nuts and
bolts
from each front

engine
support. Disconnect the
engine
ground strap.
Remove the
engine
supports.
Lower
the
engine
slightly to permit access to the two top
bolts
on
the flywheel housing.
s. Remove the
bolts
which attach the flywheel
housing to the engine.

t.
Pull
the
engine
forward, or
roll
the vehicle back­

wards,
until the clutch clears the flywheel housing.

Lift
the
engine
from the vehicle.

D-6. 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 ap­
plicable
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.
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 repair

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.

NOTE:
If the
engine
is being disassembled because
of possible valve failure, check the valve tappet
clearance
before disassembly. Improper valve

clearance
could be the possible cause of valve

failure,
indicating a need for more frequent valve
checks and adjustments. 41

D

HURRICANE
F4
ENGINE

10442

FIG.
D-l6—SHIM
STOCK
IN
POSITION
ON
MAIN
BEARING

1—0.001"
Feeler Stock H' Wide feeler stock with light
engine
oil and lay it on the

bearing
in the cap, as shown in
Fig.
D-16.
With
the

shim
in this position, install the bearing and cap
on the crankshaft.

b.
Tighten the bearing cap nuts, first one and
then the other, a little at a time to 35 to 45 lb-ft. torque [4,8 a 6,2 kg-m.].

c.
Turn
the crankshaft by hand not more than
one inch in either direction.

Caution:
Turning
the crankshaft more may imbed the shim stock in the bearing, giving a false indica­
tion of fit and damaging the bearing.

If
the bearing clearance is correct, the piece of .001"
feeler stock should produce a light to heavy drag.
If
there is little or no drag the bearing fit is too

loose.
If the crankshaft
will
not
turn
there is not
enough clearance. In either case another bearing must be selected to provide the proper fit.

d.
After the bearing has been correctly fitted, remove the shim stock, wipe the bearing and

journal
carefully and apply clean
engine
oil to the
surfaces.
Replace the cap and tighten the nuts first one, then the other, a little at a time, to the
prescribed
torque. The crankshaft should now
turn

freely without drag.
FIG.
D-l
7—CONNECTING
ROD
OFFSET
D-47.
Connecting Rod Bearings

The
connecting rod bearings, like the crankshaft
main
bearings, are of the replaceable type. When

correctly
installed, the bearings provide proper
clearance
without filing, boring, scraping, or

shimming.

Main
bearings with maximum wearing surfaces
are
obtained through the use of
offset
connecting

rods.
When the rods are installed, the
offset
"A"

in
Fig. D-l7 is placed away from the nearest main

bearing
"B".
The
oil spray
hole
should be on the "follow" side

or
away from the camshaft, toward the right side
of the vehicle. Because of the
offset
and oil spray
hole, No. 1 and 2 or No. 3 and 4 connecting rods cannot be interchanged for if they are reversed,
the oil spray
hole
will
be on the wrong side. No. 1
and
3 or No. 2 and 4 can be interchanged.

Connecting
rod bearings should be replaced as a complete set.
Each
bearing consists of two halves.

Connecting
rod bearing
sets
are available in stand­

ard
size and the following undersize:
.001" [0,025 mm.] .012" [0,305 mm.]
.002"
[0,051
mm.] .020" [0,508 mm.] .010"
[0,254
mm.] .030" [0,762 mm.]

The
.001" and .002" undersize bearings are for use

with
standard size crankshafts having slightly

worn
crankpins that do not require grinding. The .012" undersize bearings are for use with slightly

worn
crankshafts that have been previously ground for .010" undersize bearings.

Should
it be necessary to replace the bearings due to wear, replacement of piston rings and piston
pins is also recommended.

NOTE:
Should it be necessary to replace a scored

or
burned No. 1 connecting rod bearing, see Par. D-92 regarding timing gear oil jet.

D-48.
Connecting Rod Bearing Inspection

The
bearing fits may be roughly checked by shaking the connecting rod by hand,
prior
to removal of
the bearing cap, to determine if it is
loose
on the
crankshaft.
The crankpins must be carefully in­
spected as detailed previously in Par. D-41.
Worn
crankpins
will
require undersize bearings. Scored,
flaked,
or
worn bearings must be replaced.

D-49.
Installing Connecting Rod Bearings
New bearings must be installed so that the oil

spray
hole
in the upper bearing
half
aligns with
the oil spray
hole
in the connecting rod.
Each

bearing
cap must be installed to seat evenly on the connecting rod from which it was removed, and in
the same position. After wiping and carefully in­ specting the bearing bore in the connecting rod,

install
the proper bearing. Never file either the
bearing
cap or the bearing to compensate for too
much
clearance. Do not use shims under a bearing
cap or behind a bearing shell. Do not run a new

bearing
half
with a worn half.

The
desired running fit (difference
between
the diameter of the
crankpin
and the inside diameter
of the fitted bearing) for a connecting rod bearing
is .0003" to .0025"
[0,0076
a
0,0635
mm.].
With
a dimension in
excess
of this standard running fit, a 52

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL

D D-l 13. HURRICANE
F4
ENGINE SPECIFICATIONS

MODEL:
ENGLISH
ENGINE:

Type

Number of Cylinders

Bore
Stroke
Piston Displacement...........
Bore
Spacing (center to center): 1 and 2, 3 and 4
2 and 3

Firing
Order Compression Ratio Compression Pressure... .
Number of Mounting Points:

Front
Rear

Horsepower (SAE)
Horsepower (Max Brake) Maximum Torque @
2000
rpm.
PISTONS:

Material
Description

Length
,.
Diameter (near
bottom
of
skirt).

Weight.
Clearance
Limits:
Piston-To-Cylindcr
Bore

Ring
Groove Depth:
No. 1 and 2 Ring No. 3 Ring

Ring
Groove Width:
No. 1 Ring No. 2 Ring
No. 3 Ring
Piston Pin Hole Bore
Cylinder
Bore — Standard.....
—
max. out of round
F-Head

4

W

134.2 cu. in.

3.437"

4.938"

1-3-4-2
6.7:1
120 to 130 psi.
2
1
15.63

@
4000
rpm. 114 lb-ft. 75

-
max. taper..

-
max. rebore.

PISTON RINGS:
Function:

No. 1 and 2 No. 3. .

Material:

No. 1. .
No. 2 and 3

Width;
No. 1 and 2
No. 3. . . .

Gap
(Std. to .009 Cyl. Bore).
Thickness:
No. 1 and No. 2 Rings....
No. 3 Ring
Side Clearance in Groove:
No. 1 Ring No. 2 Ring
No. 3 Ring

PISTON
PINS:
Material

Length
Diameter

Type

Clearance
in Piston
(selective
fit).
Aluminum
Alloy

Gam
Ground, T-slot, Tin Plated

3.1225*
to
3.1245*
13.5 oz.
Selective Feeler Fit
.1593" to .1655"
.1693" to .1755"
.0955" to .0965" .095" to .096"
1875" to .1885" .760" to .770"

3.125"
to
3.127"
.005" .005" .040"
Compression
Oil

Cast
Iron,
Chrome-plated Face
Cast
Iron

.007" to .017"
.134" to .144" .115" to .125"
.002" to .004"
.0015" to .0035" .001" to .0025"

SAE
1016 Steel
2.781"
.8119"

Locked
in Rod

.0001"
to .0003"
METRIC

7,937
cm.

11,112
cm. 2199 cm*

8,729
cm.

12,542
cm.
8,4 a 9,2 kg-cm2
15,77 kg-m.
9,525
cm.

7,9311
a
7,9362
cm.

382,7
gr.

4,046
a
4,203
mm.
4,300
a
4,457
mm.

2,4257
a
2,4511
mm. 2,413 a
2,438
mm.

4,7625
a
4,7879
mm.
19,304
a
19,558
mm.
7,9375
a
7,9425
cm.

0,1270
mm.

0,1270
mm.
1,0160
mm.
2,38 mm.
4,76 mm.
0,178 a
0,432
mm.

3,403
a
3,657
mm. 2,821 a 3,175 mm.
0,051 a 0,102 mm.
0,038
a
0,088
mm.

0,025
a
0,063
mm.

70,637
mm.

20,6223
mm.

0,0025
a
0,0076
mm. 71

Dl

DAUNTLESS
V-6
ENGINE
DM.
GENERAL

This
section describes service and repair of the
Dauntless V-6 engine. The
engine
code
number shown in
Fig.
A-4 is provided to identify the Daunt­

less
V6-225 engine. The meaning of the coded letters and numbers that are stamped on the right front face of the crankcase, just below the rocker
arm
cover,
between
exhaust manifold ports, is given
below.
Letter
to
Designate
Market

M
—
Military
E
—
Export

D
— Domestic
Letter
to
Designate
Year
Built

N
— 1967
P
— 1968

R
— 1969
S
— 1970

T
— 1971

Letter
to Designate
Engine
and Compression
Ratio

H—V6-225
9.0 to 1
C.R.
(2 Bbl.
Carb.)
Y—V6-225
9.0 to 1
C.R.
Marine
(Low
Profile)
(2
Bbl.Carb.)
Z—V6-225
9.0 to 1
C.R.
Marine
(High
Profile)
(2 Bbl.
Carb.)

K—V6-225
7.6 to 1
C.R.
(2 Bbl.
Carb.)
L—V6-225
7.4 to 1
C.R.
(2 Bbl.
Carb.)

Market

Domestic
—

Year
"1967"
Engine
J

Day

Plus Chg. If
Any-
Service Engine "S"
Short
Block
"R" -Oversize Bores "B"
Undersize Crank

&
"A"

Rod
Bearings

The
identifying letter or letters follow the
engine
letters are decoded as follows:
A—.010"
Undersize
Main
and Connecting Rod
Bearings

B—.010"
Oversize Pistons

AB—Combination
of A and B
S—Service
Engine

R—Short
Block

All
disassembly and assembly procedures are pre­ sented in logical order, assuming a complete
engine

overhaul
with
engine
removed from the vehicle.

However,
many of
these
procedures can also be
performed as on-vehicle services if vehicle or
engine
components are removed to gain access to parts
involved.

Note:
Some
engines
are equipped with an exhaust
emission control system. Service information on
the components of this system is given in sec­ tion F2.

Dl-2.
ENGINE
DESCRIPTION

The
Dauntless V-6
engine
has a displacement of
225 cubic inches. It has a compression ratio of
9.0 to 1, which permits use of regular-grade
gaso­

line.
See
Figs.
Dl-1 and Dl-2.

The
cylinder block is made of cast
iron.
Two banks
of cylinders (three cylinders per bank) are cast at a
90-degree
angle. The lower part of the cylinder-

block
extends
below the centerline of the
crank­
shaft, forming a continuous flat surface with the

rear
crankshaft main bearing cap and the timing

chain
cover.
This
design allows installation of an
oil
pan with a
one-piece
gasket. The cylinders in
the left bank (as viewed from the driver's seat) are
numbered
1-3-5,
from front to
rear.
The cylinders

in
the right bank are numbered
2-4-6,
from front
to
rear.

The
crankshaft is supported in the cylinder block
by four steel-backed full-precision bearings, all of

which
have an identical diameter.
Crankshaft
main bearings are numbered 1 to 4, front to
rear.
The

thrust
bearing is flanged to maintain crankshaft position and to compensate against crankshaft end

thrust
The No. 2 bearing is the thrust bearing.

The
crankshaft is counterbalanced by weights,
which
are cast integral with the
crank
cheeks. The

weights
are shaped to a contour which
gives
mini­
mum
clearance with cylinder barrels and piston

skirts
to conserve space.

Connecting
rods have I-beam sections with
bosses

on each side. Metal is removed, as required, to secure correct weight and balance. The lower end
of each connecting rod has a steel-backed preci­
sion bearing. The piston pin is a press fit into the upper end. The outer ends of the piston pin

are
a slide fit in the piston
bosses.

The
full-skirted, aluminum alloy pistons are cam ground and tin plated. Two compression rings and
one oil control ring are installed above the piston
pin.
The cast iron compression rings in the two

upper
grooves
of the piston have a
groove
or bevel cut around the inner
edge
on one side. The
top compression ring is installed with this
groove
or
bevel up. The lower compression ring is installed

with
bevel down. The oil
ring,
in the lower groove,
consists of two thin steel
rails
separated by a

spacer.
It is backed by a hump-type spring-steel
expander.

V-6
engine
cylinder heads are made of cast
iron.

Their
valve
guides
are cast integrally. Right and left cylinder heads are identical and interchange­
able. In service, however, it is
good
practice to
install
the cylinder heads on the side from which
they were removed.

The
valves are in line in each head, at an angle
10°
above the centerline of the cylinder bores.

Each
valve has a spring strong enough to ensure
positive valve seating throughout the operating speed range of the engine. The valve rocker arm
mechanism is protected by a
sheet
metal cover.
This
cover is seated on a raised surface of the
cylinder
head. It is gasketed to prevent oil leaks.

The
rocker arms for each bank of cylinders are mounted on a tubular steel shaft, supported on
the cylinder head by brackets. The rocker arms
are
made of aluminum. They have inserts at the

push
rod socket and the valve stem contact face.

The
camshaft is located above the crankshaft be­
tween the two cylinder banks; it is supported in
four steel-backed babbitt-metal bearings. The cam­ shaft is driven at one-half crankshaft speed by
sprockets and a single outside-guide type chain.

Hydraulic
valve lifters and
one-piece
push rods operate overhead rocker arms and valves of both

banks
of cylinders from a single camshaft.
This

system requires no lash adjustment during assem­
bly
or in service.

In
addition to its normal function of a cam follower,
each hydraulic valve lifter also serves as an auto- 76

'Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL

Dl

12713

FIG.
Dl-11—MEASURING
TELESCOPE GAUGE
1—
Telescope
Gauge
2—
Micrometer

may
be measured with an inside micrometer or
by setting the cylinder
gauge
dial
at zero and meas­
uring
across the
gauge
contact points with an out­side micrometer while the
gauge
is at same zero
setting. Refer to
Figs.
Dl-10 and Dl-11.

b.
If a cylinder bore is moderately rough or slightly

scored,
but is not out-of-round or tapered, it is

usually
possible to remedy the situation by honing
the bore to fit a standard service piston, since
standard
service pistons are high-limit production
pistons. If cylinder bore is very rough or deeply
scored,
it may be necessary to rebore the cylinder
to fit an oversize piston in order to ensure satisfac­
tory
results.

c.
If cylinder bore is tapered .005" [0,127 mm.]

or
more or is out-of-round .003" [0,076 mm.] or

more,
it is advisable to rebore for the smallest possible oversize piston and rings.

d.
Carefully
inspect the cylinder block for small

cracks
or fractures, and for porosity.
Rust
in any
cylinder
bore may indicate a leak.

e.
Inspect all machined surfaces for scoring and

burrs.
With
a straight
edge
and feeler
gauge,
check
each
machined surface for distortion.

D1-37.
Cylinder Block Repair
If
one or more cylinder bores are rough, scored, or

worn
beyond prescribed limits, it
will
be necessary
to correct bores and fit new pistons.

If
relatively few bores require correction, it
will

not be necessary to rebore all cylinders to the same
oversize in order to maintain
engine
balance, since
all
oversize pistons are held to the same weights as

standard-size
pistons. If conditions justify replace­
ment of all pistons, however, all new pistons should
be the same nominal size.

Standard-size
service pistons are high-limit, or

maximum
diameter; therefore, they can usually be installed after a slight amount of honing has
been
done
to correct slight scoring or excessive

clearances.
This
applies
primarily
to
engines
which
have relatively low mileage. Service pistons are also furnished in .010"
[0,254
mm.] oversize. All

service
pistons are diamond bored, and selectively
fitted with piston pins; pistons are not furnished
without pins.

Caution:
Do not attempt to cut down oversize pis­

tons
to fit cylinder bores as this
will
destroy the

surface
treatment and affect the weight. The small­
est possible oversize service pistons should be used

and
the cylinder bores should be honed to size

for
proper clearance.

Before
honing or reboring cylinders, measure all new pistons with a micrometer, on an axis perpen­

dicular
to the piston pin. Select the smallest piston

for
the first fitting. The slight variation usually
found between pistons in a set may provide for
correction
in case the first piston tried is too

small.

If
wear at top of cylinder
does
not exceed .005" [0,127 mm.]
excess
diameter, or exceed .003"
[0,076 mm.] out-of-round, honing is recommended.

If
wear or out-of-round
exceeds
these
limits, the
bore should be reground with a boring bar of the

fly
cutter type, then finish-honed.

When
reboring cylinders, all crankshaft bearing caps must be in place and tightened to proper
torque to avoid distortion of bores in
final
assem­
bly.
Always be sure the crankshaft is out of the

way
of the boring cutter when boring each cylinder.
When
boring, leave the diameter .001" [0,025 mm.]

undersize,
then finish hone to obtain the required

clearance.

When
honing cylinders, use clean sharp
stones
of
proper
grade for the amount of metal to be re­
moved. Refer to instructions supplied by the hone
manufacturer.
Dull
or dirty
stones
cut unevenly

and
generate excessive heat. When using coarse

or
medium grade
stones,
leave sufficient metal so
that all
stone
marks can be removed with the fine
stones
used to finish-hone to proper clearance.

When
finish-honing, pass the hone through the entire length of cylinder at a rate of approximately 60 cycles per minute.
This
should produce the

desired
45-degree
cross hatch pattern on cylinder

walls.
A proper pattern
will
ensure maximum
ring
life and minimum oil consumption.

After
final
honing and before the piston is checked

for
fit, each cylinder bore must be washed thor­ oughly to remove all traces of abrasive, then dried completely. The dry bore should be brushed clean

with
a power-driven fibre
brush.
If all traces of

abrasive
are not removed,
rapid
wear of new pistons

and
rings
will
result.

Note:
Wipe cylinder bores with a clean white

cloth,
moistened with SAE 10 oil. Cleaning should
continue until this
test
shows no sign of
dirt.

It
is of the greatest importance that refinished

cylinder
bores be true, with .0005" [0,013 mm.]
or
less out-of-round or taper.
Each
bore must have

a
smooth surface, without
stone
or cutter
marks.
After
final
honing and cleaning, each piston must be fitted individually to the bore in which it
will

be installed. Once fitted, each piston should be
marked
with its cylinder number to assure correct

installation.
85

Dl

DAUNTLESS
V-6
ENGINE
Dl-38.
Crankshaft
Cleaning

Clean
the crankshaft thoroughly with a suitable
cleaning solvent.
Clean
drilled oil
passages
in its

journals
with a small rifle brush to remove all
sludge
or gum deposits; dry
passages
with com­
pressed air.

Dl-39.
Crankshaft
Inspection
and
Repair

If
the crankshaft has not
been
removed from the

cylinder
block for inspection, disconnect two con­ necting rods at a time from crankshaft. Inspect
the bearings and crankpin journals. While turning
crankshaft,
it is necessary to temporarily reconnect
the rods to crankshaft to avoid possibility of dam­ aging the journals through contact with uncon­
nected rods.
Inspect the crankpins visually for excessive or ir­

regular
wear, and for scoring. Use an
outside
micrometer to check crankpins for out-of-round.
Standard
crankpin
diameter is
2.0000"
[5,080
cm.].

If
crankpins are more than .0015"
[0,0381
mm.]
out-of-round, new bearings cannot be
expected
to
have satisfactory life.
If
the crankshaft has
been
removed from the
cyl­

inder
block for inspection support it on V-blocks
at its main bearing journals 1 and 4. Inspect the

main
bearing journals visually for excessive or ir­

regular
wear, and for scoring. Standard main bear­
ing
journal
diameter is 2.4995"
[6,349
cm.].
Total

indicator readings at each
journal
should not ex­
ceed .003"
[0,076
mm.].

Check
run out at all four journals and
note
high
spot
(maximum eccentricity) of each
journal.
High

spot
of each
journal
should
come
at the same
angular
location. If high
spots
do not coincide,

crankshaft
is misaligned and unsatisfactory for
service.

If
crankpin or main bearing journals are scored,
ridged, or out-of-round, the crankshaft must be replaced or reground to a standard undersize bear­
ing diameter to ensure satisfactory life of bearings. Slight roughness can be removed with a fine grit
polishing cloth thoroughly
wetted
with
engine
oil.
Burrs
can
be
honed with a fine oil
stone,
so long as
bearing clearances
will
remain within specified
limits.

Dl-40.
Crankshaft
Main
Bearings

A
crankshaft bearing consists of two halves which
are
neither alike nor interchangeable. One half is

carried
in the corresponding main bearing cap; the
other half is located
between
the crankshaft and

cylinder
block. The upper (cylinder block) half
of the bearing is grooved to supply oil to the con­ necting rod bearings, while the lower (bearing cap)

half
of the bearing is not grooved. The two bearing
halves must not be interchanged. All crankshaft
bearings
except
the thrust bearing and the
rear

main
bearing are identical. The thrust bearing (No. 2) is longer and it is flanged to take
crank­

shaft end thrust. When the bearing halves are
placed in cylinder block and bearing cap, the
ends
extend slightly beyond the parting surfaces. When
cap
bolts
are tightened, the halves are clamped
tightly in place to ensure positive seating and to
prevent turning. The
ends
of bearing halves must never be filed flush with parting surface of
crank­

case or bearing cap.

Crankshaft
bearings are the precision type which
do not require reaming to size or other fitting.
Shims
are not provided for adjustment since worn
bearings are readily replaced with new bearings of proper size. Bearings for service replacement are

furnished
in standard size and undersizes. Under no circumstances should crankshaft bearing caps
be filed to adjust for wear in old bearings.

Dl-41.
Crankshaft
Main
Bearing
Cleaning
and
Inspection

Clean
main bearing surfaces. Inspect the bearings

visually
for excessive or uneven wear, scoring, and

flaking.
Visibly worn or damaged bearings must
be replaced. It is necessary to check
radial
clear­ ance of each new or used crankshaft main bearing
before installation.
This
can be
done
by either of two methods, which are described in
Pars.
Dl-42

and
Dl-43.

a.
The desired
radial
clearance of a new bearing
is .0005" to .0021"
[0,0127
a
0,0534
mm.].
b. Replacement bearings are furnished in standard
size, and in several undersizes, including undersizes
for reground journals. If a new bearing is to be installed, try a standard size; then try each under­
size in turn until one is found that
meets
the
specified clearance limits.

Note:
Each
undersize bearing half has a number
stamped on its outer surface to indicate amount of undersize. Refer to Fig. Dl-12. 14288

FIG.
Dl-12—LOCATION
OF
UNDERSIZE
MARK
ON
BEARING
SHELL

1—
Tang

2—
Undersize
Mark
Dl-42.
Main
Bearing
Fitting,
Plastigage

Bearing
clearance can be checked by use of Plasti­
gage,
Type PG-1 (green) which has a range of
.001" to .003" [0,025 a
0,076
mm.]. Refer to

Fig.
Dl-13.

a.
Place a piece of Plastigage lengthwise along the
bottom
center of the lower bearing half, then 86