check oil JEEP CJ 1953 Workshop Manual

D
HURRICANE
F4
ENGINE
D-101.
Install
Manifold

If
manifold studs were removed for replacement,
apply sealer on the stud threads
before
installing
a
new stud.
See Section Fl for exhaust emission controlled

engines.
Make
certain that no foreign objects are inside the manifold and that all
passages
are clear. Place a
new set of manifold
gaskets
in position on the side
of the cylinder block.
Then,
carefully slide the manifold
onto
the studs and against the cylinder block being careful not to damage the gaskets.
Torque
all manifold attaching nuts evenly 29 to
35 lb-ft. [4,0 a 4,8 kg-m.].
D-102.
Install
Oil
Filler
Tube

When
installing the oil filler tube, be sure that the
beveled lower end is away from the crankshaft.
Place a
piece
of
hard
wood
over the top of the
tube

to prevent damage to the cap gasket seat.
D-103.
Install
Water Pump

Make
certain that the mating surfaces of the water pump and the cylinder block are clean and smooth.
Install
the gasket on the
flange
of the pump and

install
the pump in position on the cylinder block.
Torque
the water pump attaching
bolts
alternately

and
evenly 12 to 17 lb-ft. [1,7 a 2,3 kg-m.].
D-104.
Install
Water Outlet Fitting

Install
the thermostat and the water
outlet
fitting.
Torque
the water
outlet
fitting attaching
bolts
20
to 25 lb-ft. [2,8 a 3,4 kg-m.].
FIG.
D-42—INSTALLING HURRICANE F4 ENGINE
IN
VEHICLE

1—
Lifting
Sling
2— Hoist
Cable

3—
Hurricane
F4 Engine
4— Dowel Bolt
5—
Flywheel
Housing
D-105.
ENGINE INSTALLATION
a.
Install
lifting sling to
engine
and using suitable hoist raise the
engine
from its blocking or stand

and
then slowly lower it
into
the
engine
compart­ment of the vehicle.

Note:
When installing the
Hurricane
F4 Engine,
two % x 4 inch
guide
bolts
or
dowels
should be
used to properly
guide
and align the
engine
to the
flywheel housing (See Fig. D-42).
b. Slightly tilt the
engine
downward and at the
same time slide the
engine
rearward
while lining up the transmission main gear shaft with the clutch
throw-out bearing and disc spline.

Note
:The
engine
crankshaft may have to be turned
slightly to align the transmission main gear shaft
with the clutch disc spline.
c. Remove the
guide
bolts
or
dowels
and secure
the
engine
to the housing.

d.
Secure the front
engine
mounts to the frame brackets and
bolt
ground cable to
engine.

e. Remove lifting sling from
engine.

f. Connect exhaust pipe to
engine
manifold flange.
g. Connect throttle and choke cables to carburetor.
h.
Install
fan to water pump pulley.
i.
Connect fuel pump line to main fuel line,

j.
Replace starting motor assembly. k. Connect
engine
wiring harness connectors at
front of cowl.

I.
Connect wires to starting motor assembly, water
temperature and oil pressure sending units and alternator.

NOTE:
ON
ENGINES EQUIPPED WITH EX­

HAUST
EMISSION CONTROL,
REPLACE
THE
AIR
PUMP,
AIR
DISTRIBUTOR
MANI­

FOLD,
AND
ANTI-BACKFIRE (DIVERTER)
VALVE.
SEE
SECTION
Fl.
m. Replace radiator and radiator grille support
rods and connect coolant
hoses
to
engine.

Note:
Replace heater
hoses
if vehicle is equipped
with hot water heater.

n. Fill
radiator with coolant and
engine
with oil
(see
Lubrication
Chart).

o.
Install
air cleaner and connect carburetor air
hose.

p. Connect battery cables and start
engine,

q.
Install
hood
and road
test
vehicle.
D-103.
FINAL
IN-VEHICLE
ADJUSTMENTS
a.
Clean
battery terminals and check battery. b.
Check
ignition terminals and check battery.
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. 68

'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

'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

©©©©©©©©©

12697

FIG.
Dl-1—DAUNTLESS
V-6
ENGINE, SIDE SECTIONAL VIEW

1—
Fan
Blade
2—
Fan
Spacer

3—Fan
Pulley
4—
Water
Pump 5—
Timing
Chain
Cover
6—
Camshaft
Sprocket
7—
Thermostat
Bypass Hose
8—
Thermostat
Housing
9—
Thermostat

10—
Carburetor

11—
Intake
Manifold
12—
Rocker
Arm Cover 13—
Cylinder
Block 14—
Push
Rod
15—
Camshaft

16—
Flywheel
17—
Clutch
Pressure Plate
18—
Clutch
Driven Plate
19—
Clutch
Pilot Bearing
20—
Oil
Seal Packing
21—
Rear
Main
Bearing Shell
22— Connecting Rods
23—
Rear
Center
Main
Bearing Shell
24—
Oil
Screen
25—
Oil
Screen Pipe and Housing
26—
Oil
Pan 27—
Front
Center
Main
Bearing Shell
28—
Crankshaft

29—
Front
Main
Bearing Shell
30—
Timing
Chain

31—
Crankshaft
Sprocket
32—
Oil
Slinger
33—
Oil
Shedder 34 Oil Shedder Packing
35—
-Woodruff
Key
36—
"Vibration
Damper
37—
Crankshaft
Pulley
38—
Fan
Belt matic adjuster, to prevent lash in the valve operat­
ing linkage. Hydraulic valve lifters also provide

a
cushion of oil to absorb operating shocks. As shown in Fig. Dl-3, all parts of a hydraulic lifter

are
housed in the body, which is the cam follower.

At
the beginning of valve operation, the valve lifter body rests on the camshaft base circle.

Plunger
spring tension prevents lash clearances in the valve linkage.

As
the camshaft forces the valve lifter body up­

ward,
both oil in the lower chamber and check

ball
spring
tension firmly seat the check ball against the plunger to prevent appreciable
loss
of oil from
the lower chamber. Oil pressure forces the plunger
upward,
with the body, to operate the valve linkage.

As
the camshaft rotates to closed-valve position, the valve spring forces the linkage and lifter down­

ward.
When the
engine
valve seats, the linkage

parts
and plunger stop, but the plunger spring forces
the body downward .002" to .003"
[0,050
a
0,076
mm.] until it again rests on the camshaft base

circle.
Oil pressure then forces the check ball away

from
its seat and allows passage of oil past the check ball into the lower chamber.
This
replaces
the slight amount of oil lost by leakage. During
the valve opening and closing operation, a very
slight amount of oil escapes
between
plunger and body, and returns to the crankcase.
This
slight
loss
of oil (leak-down) is beneficial. It provides a
gradual
change of oil in the valve lifter; fresh oil
enters the lower chamber at the end of each cycle
of operation. 77

Dl

DAUNTLESS
V-6
ENGINE
This
will
prevent damage to piston rings or
crack­

ing piston lands during removal.
b. Use a silver pencil or quick-drying paint to mark
the cylinder number on all pistons, connecting rods,
and
caps. Starting at the front end of the crankcase,
the cylinders in the right bank are numbered 2-4-6
and
in the
left
bank are numbered
1-3-5.

c. Remove cap and lower connecting rod bearing

half
from No. 1 connecting rod.

d.
Push the piston and rod assembly away from
the crankshaft and remove it from top of cylinder bore. Then install cap and lower bearing half on
connecting rod.
e. Remove each connecting rod and piston as­ sembly as described in c and d, above.
FIG.
D1-9—CRANKSHAFT
MAIN
BEARING
CAPS

1—Thrust
Bearing
D1-32.
Remove
Main
Bearing and Crankshaft
a.
This
engine
has four crankshaft main bearings.

Front
to
rear,
they are numbered 1 to 4. Refer to

Fig.
Dl-9. With a silver pencil or quick-drying
paint, mark the bearing number on each main bearing cap.
b. Remove two
bolts
which secure first (front)

main
bearing cap to
engine
cylinder block. With

a
lifting bar, carefully pry the cap from the crank­ shaft and block. Be careful not to damage the cap,
block or crankshaft. Remove the bearing cap, with
lower main bearing half, from the cylinder block.

Keep
bearing half and cap
together.
Similarly, remove the next two main bearing caps with lower

main
bearing halves. To remove
rear
main bearing
cap,
use
rear
main bearing remover bolt W-323.
c. Remove the fabric seal from inside diameter of
fourth (rear) main bearing cap, and remove neo-
prene composition seal from outer surface of this
bearing cap. Discard both seals.

d.
Lift
and remove the crankshaft from
engine
cylinder
block. Do not remove upper main bearing
halves from block or lower main bearing halves

from
caps at this time. Mount main bearing caps

in
their original positions.
Dl-33.
ENGINE
CLEANING,
INSPECTION,

AND
REPAIR

The
cleaning, inspection, and repair procedures
detailed herein are recommended to be followed
when a
complete
engine
overhaul is to be made
with the
engine
out of the vehicle. These instruc­
tions
can generally be applied individually with the

engine
in the vehicle. Wherever the procedure dif­
fers due to the
engine
being in the vehicle, the necessary special instructions are provided. Inspec­
tion and repair instructions are included to cover
the cylinder block, cylinder head, crankshaft and bearings, connecting rods and bearings, oil pump,
valves and tappets, pistons and rings, flywheel,
timing gears, and the camshaft and bearings. In
addition, fitting operations for
these
engine
com­

ponents
are included.

D1-34.
Cylinder Block

The
cylinder block must be cleaned thoroughly, inspected, and repaired as necessary, as described
below.

Dl-35.
Cylinder Block Cleaning
Steam-clean the cylinder block, or clean it with

a
suitable cleaning solvent A scraper can be used
to remove
hard
deposits, but do not score machined
surfaces. Be certain that oil passages, valve cham­

bers,
crankcase, and cylinder walls are free from sludge, dirt, and carbon deposits. After cleaning,

dry
the cylinder block carefully with compressed
air.

Dl-36.
Cylinder Block Inspection

a.
Inspect cylinder walls visually for scoring,
roughness, or ridges which indicate excessive wear.
Check
cylinder bores for taper and out-of-round
with an accurate cylinder
gauge.
Measure eact bore at top, middle and bottom, both parallel tc
and
at right
angles
to the centerline of the
engine

The
diameter of the cylinder bores at any poin
FIG.
Dl-10—MEASURING
CYLINDER
BORE

1—Telescope Gauge [90*
From
Piston Pin]
84

'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

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL
Dl
A 8

j
13415

FIG.
Dl-13—USING
PLASTIGAGE
TO
MEASURE
BEARING CLEARANCE

1— Plastigage
A—Start

2—
Scale
B—Flattened

install
cap with shell and tighten
bolts
80 to 110 lb-ft. [11,1 a 15,2 kg-m.] torque.

Caution:
Do not turn crankshaft with Plastigage

in
bearing.

b.
Remove bearing cap with bearing half. The
flattened Plastigage
will
adhere either to the bear­ ing half or the
journal.
Do not remove it.
c. Using the scale printed on the Plastigage en­

velope,
measure Plastigage width at its widest
point. The number within the graduation which
most
closely corresponds to the width of Plasti­
gage
indicates the bearing clearance in thousandths
of an inch.

DI-43.
Main Bearing
Fitting,
Feeler or
Shim
Stock

A
small strip of feeler or shim stock can be used
to check main bearing clearance. The method is
simple, but care must be taken to avoid damage
to the bearing surface from excessive pressure against the strip.

a.
Cut a rectangular piece of feeler or shim stock, .001"
[.0254
mm.] thick,
i/2"
[12,70
mm.] wide, and
Vs"
[3,175 mm.] shorter than the bearing width.
Position the bearing cap to the crankshaft journal
and
cylinder block, and install two cap
bolts
loosely.

b.
Tighten alternate cap bolts, a little at a time,

until
both have
been
tightened to 35 to 45 lb-ft. [4,8 a 6,2 kg-m.] torque.
c.
Turn
the crankshaft by hand, no more than one

inch
[2,5 cm.] in either direction.

Caution:
If the crankshaft is turned too far, it
will

embed the strip in the bearing surface.
This
will
damage the bearing and also cause a false indica­tion of bearing clearance.

If
bearing clearance is correct, the strip should cause a light to heavy drag, or resistance to rotation.
If
there is little or no drag, clearance is too great;

if
the crankshaft cannot be turned, clearance is
insufficient. In either case, a different main bear­ ing must be
selected
to obtain proper clearance.

d.
Repeat
steps
a, b, and c, as necessary, to
select

proper main bearing size. After a bearing has
been

selected, remove the
test
strip from bearing on
crankshaft
journal surface; wipe both surfaces care­

fully,
and apply clean
engine
oil to both surfaces. Position the bearing cap to the crankshaft journal

and
cylinder block, and install two cap
bolts
loosely.

Tighten
alternate cap bolts, a little at a time, to

final
specified torque of 80 to 110 lb-ft. [11,1 a 15,2 kg-m.]. The crankshaft should now rotate
freely.

Dl-44.
Piston
and
Connecting
Rod
Disassembly

a.
Remove two compression rings with a piston
ring
expander. To remove oil ring, remove the two

rails
and spacer-expander, which are separate
pieces

in
each piston third
groove.

b.
From
Tool Set W-338 use support base J-6047-1
with collar J-6047-5 and driver J-6047-4 with an
arbor
press to press piston pin from piston and con­
necting rod. Mount support base and collar in press. Set driver in position and press out pin. Refer to

Fig.
Dl-14.
FIG.
Dl-14—PISTON
PIN
REMOVAL

1—
Arbor
Press

2—
Driver

3—
Piston
and Rod Assembly
4—
Collar
•
5—Support Base Dl-45.
Piston
and
Connecting
Rod
Cleaning
and Inspection

a.
Clean
carbon from piston surfaces and under­
side of piston heads, and remove all pistons rings.
Clean
carbon from ring
grooves
with a suitable tool.
Remove any gum or varnish from piston skirts with a suitable solvent.

b.
Carefully examine pistons for rough or scored
bearing surfaces, cracks in
skirt
or head, cracked

or
broken ring lands, chipping and uneven wear 87

Pi

DAUNTLESS
¥-6
ENGINE
which
would cause rings to seat improperly or have
excessive clearance in
ring
grooves. Damaged or
faulty
pistons should be replaced,
c.
Inspect bearing surfaces of piston pins and check

for
wear by measuring worn and unworn surfaces

with
a micrometer. Rough or worn pins should be
replaced.
Test fit the piston pins in piston
bosses.
Occasionally,
a pin
will
be tight due to gum or

varnish
deposits.
This
may be corrected by remov­

ing
the deposit with a suitable solvent. If piston
bosses
are worn out-of-round or oversize, the piston

and
pin assembly must be replaced. Oversize pins
are
not
practical,
since the pin must be a press fit
in
the connecting rod bore. Piston pins must fit the
piston with an easy finger push at
70°F.
[21°C.].

They
should have .0004" to .0007"
[0,0178
a
0,0102
mm.] clearance.

Dl-46.
Piston Fitting

If
cylinder bores are rebored or heavily honed,
new and possibly oversize diameter pistons must be
installed.
A new piston must be fitted to its cylinder

bore.
A satisfactory method of fitting pistons is as
follows.

a.
Expand
a
telescope
gauge
to fit the cylinder bore at right angles to the piston pin and
between
1
Vi"
to 2" [3,7 a 5,1 cm.] from the top.

b.
Measure diameter of the piston to be fitted, as
shown in
Fig.
Dl-15. The piston must be measured

at
right angles to the piston pin, W [6,3 mm.] below the oil
ring
groove. The piston must be be-
FIG.
Dl-15—MEASURING
PISTON

1—90°
tween .001" and .0015" [0,025 a
0,038
mm.]

smaller
than the cylinder bore.

Note:
Both cylinder block and piston must be at

very
nearly the same temperature when measure­
ments are made or
errors
due to expansion
will
occur.
A difference of 10°F.
[5,6°C]
between
parts
is sufficient to produce a variation of .0009"
[0,0023
mm.].

The
pistons are cam-ground, which means that the
diameter at a right angle to the piston pin is
greater
than the diameter
parallel
to the piston

pin.
When a piston is checked for size, it must be
measured
with a micrometer applied to the
skirt

along a line
perpendicular
to axis of the piston pin.

Dl-47.
Piston Ring Fitting

When
new piston rings are to be installed without

reboring
cylinders,
the glazed cylinder walls should
be slightly dulled. However, cylinder bore diameter
should
not increase more than necessary.
Cylinder

walls
should be honed with the finest grade of
stone
to remove any glaze.
New compression rings must be checked for clear­ ance in piston
grooves
and for gap in cylinder bores;
however, the flexible oil rings are not checked for gap. The cylinder bores and piston
grooves
must
be clean, dry, and free of carbon and
burrs.

With
rings installed on piston, check clearance in
grooves
by inserting feeler
gauge
between
each
ring

and
its lower
land.
Any
ring
groove
wear
will
form

a
step
at inner portion of the lower
land.
If the
piston
grooves
have worn enough that relatively

high
steps
exist on the lower lands, the piston
should
be replaced because the
steps
will
interfere

with
proper operation of new rings and the
ring
clearances
will
be excessive. Piston rings are not

furnished
in oversize widths to compensate for
ring
groove
wear.

When
fitting new rings to new pistons, the side

clearance
of the compression rings should be .002" to .0035"
[0,051
a
0,089
mm.] for number one (1)

ring,
.003" to .005" [0,076 a 0,127 mm.] for number
two (2)
ring,
and side clearance of the oil
ring
should
be .0015" to .0085" [0,038 a
0,220
mm.].

To
check the end gap of a compression
ring,
place

it
in the cylinder in which it
will
be used, square

it
in the bore by tapping with the lower end of
a
piston, then measure the gap with a feeler
gauge.

A
compression
ring
should not have
less
than .015"
[0,381
mm.] gap when placed in cylinder

bore.
If gap is
less
than specified value, file the
end of the
ring
carefully with a fine file to obtain

proper
gap.

Dl-48.
Piston and Connecting Rod Assembly

Note:
A connecting rod can spring out of alignment

in
shipping or handling. Always check a new con­
necting rod for misalignment before installing pis­
ton and pin.

a.
If a new connecting rod is to be installed, check
its alignment with an accurate rod alignment fix­

ture.

b.
If the piston and connecting rod assembly is
to be installed in the left cylinder bank, it must be assembled as shown in
Fig.
Dl-16. If the piston and
connecting rod assembly is to be installed in the
right
cylinder bank, it must be assembled as shown
in
Fig. Dl-17.
Note
that
these
two assemblies are

mirror-images
of each other.

c.
Lubricate
piston pin to avoid damage when

pressing
through the connecting rod.

d.
To install piston pin in piston and connecting

rod,
use
Tool
Set W-338.
Install
collar J-6047-5,
spring
J-6047-3, and pilot J-6047-20 into the base

support
J-6047-1 and place in
arbor
press. Using

driver
J-6047-4 press piston pin into piston and 88

Dl

'Jeep5
UNIVERSAL
SERIES
SERVICE
MANUAL

FIG.
Dl-16—LEFT
BANK
PISTON

AND
ROD
ASSEMBLY
(No.
1-3-5)

1—
Oil
Spurt Hole Up
2— Boss on Rod and Cap
Rearward

3—
Notch on Piston
Forward

12716

FIG.
Dl-17—RIGHT
BANK
PISTON
AND
ROD
ASSEMBLY
(No. 2-4-6)
1—
Oil
Spurt Hole Up
2— Boss on Rod and Cap
Forward

3—
Notch on Piston
Forward

14355

FIG.
Dl-18—-PISTON
PIN
INSTALLATION
connecting rod until pin
bottoms.
Refer to Fig.

Dl-18.

e.
Remove piston and connecting rod assembly
from
press. Rotate piston on pin to be certain that

pin
was not damaged during the pressing operation. 13297
1—
Driver

2— Piston Pin

3—
Piloi
4—
Spring

5—
Collar

6—
Support
Base
FIG.
Dl-19—PISTON
RINGS

1—
Compression
Rings
2—
Expander

3—
Rail

4—
Spacer

5—
Oil
Ring
f.
Install
piston rings on piston as follows. Refer
to Fig. Dl-19. Position ends of piston ring expander
over piston pin.
Install
oil ring
rail
spacer and
oil
ring
rails.
Position
gaps
in rails upward on same
side of piston as oil spurt
hole
in connecting rod.
Install
compression rings in upper two grooves. If

a
single chrome-plated compression ring is used,
the chrome ring must be installed in the top groove.

Note:
All compression rings are marked with a
dimple, a letter
"T",
a letter
"O",
or word
"TOP"

to identify the side of the ring which must face

toward
the top of the piston. If a single chrome-
plated compression ring is used, the chrome ring must be installed in the top groove.

Dl-49.
Connecting
Rod
Bearing Inspection and Fitting

a.
If connecting rod bearings are chipped or scored,
they should be replaced. If bearings appear to be
in
good
condition, check for proper
radial
clear­
ance on crankpin. If
radial
clearance
exceeds
.003" [0,076 mm.], it is advisable to install a new

bearing.
However, if bearing appears to be in
good

condition and
does
not cause noise, it
will
not be mandatory to replace it.
Radial
clearance can be
checked either with Plastigage, as described in Par.
Dl-42,
or with a strip of feeler or shim stock, as
described in Par. Dl-43. Connecting rod bearings
differ from crankshaft main bearings in that their
desired
radial
clearance is .0002" to .0023" [0,005

a
0,0585
mm.] and their cap
bolts
and nuts are to be hand torqued to a 30 to 40 lb-ft. [4,1 a 5,5
kg-m.] torque.
b. After each connecting rod bearing has been

properly
fitted, attach bearing cap
loosely
with
two cap
bolts
and nuts to keep parts of each as­
sembly
together
until installation. 89