1953 JEEP CJ recommended oil

B

LUBRICATION
B-2.
Special Lubricants

Special
lubricants are required for certain
lubri­
cation points on the 'Jeep' Universal vehicles. The

special
lubricants are necessary for proper function­ ing and maintenance of the vehicle. The
Lubrica­
tion
Chart
(Fig. B-l and B-2)
designates
the spe­
cial
lubricating points and identifies them by type

or
part number.

B-3.
Applying
Fresh
Lubricant

When
servicing or lubricating the vehicle, it is important that all old lubricant and
dirt
be re­ moved from the fitting and/or plugs before servic­
ing and that the recommended type of lubricant be used for the particular item being serviced.
Force
lubricant through the lube fittings until the lubricant being forced out of the joint is fresh

lubricant,
indicating that all old lubricant has
been removed.

B-4.
Engine
Lubrication
System —
Hurricane
F4 Engine

•
Refer to Fig. B-3.

The
engine
oil pressure system is designed to pro­
vide adequate lubrication to all working parts of
the engine. The gear-type oil pump is driven from
the
engine
camshaft. The pump is provided with a
FIG.
B-3—ENGINE
LUBRICATION
SYSTEM
—

HURRICANE
F4
ENGINE
floating, screened intake that prevents the
circula­

tion of any sediment that might accumulate in the

oil
pan. By means of this pump, the main bearing

journals
and crankpins are efficiently lubricated through an oil gallery and passages in the cylinder
block.
Oil
is forced under pressure to the main bear­
ings and through the cheeks of the crankshaft to
the connecting rod bearings. Oil is also force-fed
to the camshaft bearings, timing gears, and intake valve rocker arms. The oil pressure is controlled by

relief
valve located in the oil pump. The valve is
designed to open when excessive pressure
develops
in
the system, relieving the pressure and returning the
excess
oil to the oil pan. The cylinder walls,
piston pins, and tappets are supplied with oil from
spurt
holes
in the connecting rods. A portion of the oil is continually passed through an oil filter
which
effectively removes any foreign matter sus­ pended in the oil. A flanged section on the
rear
of
the crankshaft acts as an oil slinger and, in com­
bination with the
rear
main bearing upper and lower oil seal, prevents the leakage of oil from the

rear
end of the cylinder block. Leakage of oil from
the front end of the cylinder block is controlled by the crankshaft oil slinger and the front oil seal
installed in the timing gear cover. The oil pressure
indicator
light in the instrument panel and the oil level
gauge
or dip stick in the side of the
engine

provide a means for checking the oil pressure and

oil
level.

B-5.
Oil Pressure Gauge or Indicator
On
early
CJ-3B
vehicles an oil pressure
gauge
is
mounted on the instrument panel.
This
gauge
in­ dicates the oil pressure within the
engine
lubri­

cating system.

On
Models
CJ-5,
CJ-5A,
CJ-6,
CJ-6A,
DJ-5, DJ-6

and
later production vehicles of Model
CJ-3B
a
red
telltale lamp, which operates when the ignition
switch is turned on, is lit when there is insufficient
oil
pressure to properly lubricate the engine. When

it
goes
out, operating pressure is achieved. In
normal
operation, the light is lit when the ignition
is first turned on. It
goes
out after the vehicle is

in
motion.

Failure
of the
gauge
or indicator to register normal
oil
pressure may indicate insufficient supply of oil

in
the
engine
crankcase, low or no oil pump pres­
sure,
or a fault in the
gauge
or indicator electrical

circuit.
The
engine
must be stopped immediately to prevent possible damage to
engine
bearings and
the fault corrected before restarting the engine.

B-6.
Engine
Lubrication
System — Dauntless V-6 Engine

The
engine
lubrication system (Fig. B-4) is the
force
feed
type in which oil is supplied under pres­

sure
to the crankshaft, connecting rods, camshaft bearings and valve lifters. Oil is supplied under con­trolled volume to the rocker arm bearings and push

rods.
All other moving parts are lubricated by gravity flow or splash.

The
supply of oil is
carried
in the oil pan which is filled through a filter opening in the right rocker

arm
cover. A removable oil
gauge
rod on the left side of the crankcase is provided to check oil level.

The
oil pump is located in the timing chain cover 10

'Jeep*
UNIVERSAL
SERIES
SERVICE
MANUAL

13330

FIG.
B-4—ENGINE
LUBRICATION
SYSTEM
—
DAUNTLESS
V-6
ENGINE

1—
Rocker
Arm Shaft
2—
Main
Oil
Line

3—
Oil
Inlet where it is connected by a drilled passage in the

cylinder
crankcase to an oil screen housing and
pipe assembly. The screen is submerged in the oil supply and has ample area for all operating condi­
tions. If the screen should
become
clogged
for any reason, oil may be drawn into the system over the
top
edge
of the screen, which is held clear of the

sheet
metal screen housing.

Oil
is drawn into the pump through the screen and
pipe assembly and a drilled passage in the
crank­

case, which connects to drilled passages in the
timing chain cover. All oil is discharged from the
pump to the oil pump cover assembly. The cover
assembly consists of an oil pressure relief valve,
an
oil filter bypass valve and a nipple for installa­
tion of an oil filter. The spring loaded oil pressure

relief
valve limits the oil pressure to a maximum
of 30 pounds [13.607 kg.] per square inch. The

oil
filter bypass valve
opens
when the filter has
become
clogged
to the
extent
that
4V2
to 5 pounds [2.04 a 2.27 kg.] pressure difference exists
between

the filter inlet and exhaust to bypass the oil filter
and
channel unfiltered oil directly to the main oil galleries of the engine.

A
full flow oil filter is externally mounted to the

oil
filter cover nipple on the right side of the en­ gine, just below the alternator. Normally, all
engine

oil
passes through the filter element; however, if
the element
becomes
restricted, a spring loaded bypass valve
opens
as mentioned above. The main

oil
galleries run the full length of the crankcase
and
cut into the valve lifter guide
holes
to supply

oil
at full pressure to the lifters. Connecting pas­
sages
drilled in the crankcase permit delivery of

oil
at full pressure to all crankshaft and camshaft
bearings.
Holes drilled in the crankshaft
carry
oil from the
crankshaft
bearings to the connecting rod bearings.
Pistons and cylinder walls are lubricated by oil
forced through a small notch in the bearing parting
surface on the connecting rod, which registers with
the
hole
in the crankpin
once
in every revolution. Piston pins are lubricated by splash.

Drilled
holes
in the camshaft connect the front camshaft bearing
journal
to the key slot in the front
of the camshaft. Oil flows from the
journal
into
the keyslot over the woodruff key in the space

between
the key and the camshaft sprocket and fuel pump eccentric.

The
forward end of the fuel pump eccentric in­ corporates a relief which allows the oil to escape

between
the fuel pump eccentric and the camshaft

distributor
gear. The oil stream strikes the distri­
butor shaft gear
once
each camshaft revolution, and provides ample lubrication of the timing chain and
sprockets by splash.

The
rocker arms and valves on each cylinder head

are
supplied with oil from the oil galleries through

holes
drilled in the front of the cylinder block and

cylinder
head. The
hole
drilled in the cylinder
head ends beneath the front rocker
arm
shaft brack­ et. A notch cast in the base of the rocker arm shaft

bracket
allows the oil to flow up inside the bracket

in
the space
between
the bracket and bolt, to the
hollow rocker arm shaft which is plugged at both
ends.
Each
rocker arm receives oil through a
hole

in
the underside of the shaft. Grooves in the rocker

arm
provide lubrication of the bearing surface. Oil
is metered to the push rod seat and valve stem
through
holes
drilled in the rocker arm. Excess
oil
drains off and returns to the oil pan through
passages in the cylinder head and block. Refer to
the
Lubrication
Chart
for lubrication frequency and

lubrication
type and grade.

B-7.
Chassis
Lubrication

Chassis
and
engine
should be serviced at periodic
intervals.
Most chassis lubricating points, whether
long-life or conventional, have standard lubrication
fittings. Refer to the
Lubrication
Specifications and

Service
Maintenance Schedule for specific points

and
lubricating time intervals. It is not necessary
to disassemble prepacked joints to lubricate them.

Merely
add new lubricant, as described in Par.
B-3,
to remove all old lubricant.

At
the appropriate interval, clean each lubrication
fitting indicated on the Lubrication
Chart
and
Service
Maintenance Schedule. Use a pressure gun
to lubricate. Be sure the grease channels are open
to provide complete lubrication of bearing surfaces.
In
some
cases it may be necessary to disassemble
to clear plugged channels.

When
vehicles are driven primarily in abnormally dusty or wet areas or when a vehicle is subject to
severe operating conditions, perform
these
services
more frequently. Under
these
conditions, no definite interval can be recommended because of the great variety of
uses
and conditions of use. 11

B
LUBRICATION B-3.
SERVICE
MAINTENANCE
SCHEDULE

Perform
the following operations at the mileage shown. Two thousand miles equals
3,200
km.

SERVICE
MAINTENANCE
SCHEDULE

OPERATION
VEHICLE
^ n>
MILEAGE
IN
THOUSANDS

6 8 10 12 24 30
Check Wheel Nut Torque*
Check
Fluid
Level
in Battery X Check
Fluid
Level
in Brake Master Cylinder0. X
Service
Cooling
System X Service Tires X

Lubricate
Distributor
Cam Lubricator (F4-134) X
Lubricate
Steering Linkage X

Lubricate
Propeller Shaft Universal Joints X

Lubricate
Propeller Shaft
Slip
Joints ; X
Lubricate
Tie Rod and Drag
Link
Sockets................................... X Change Engine
Oil
and
Filter,
and Service Air Cleaner (F4 134 Engine)** X
Change Engine Oil and
Filter,
and Service Air Cleaner (V6-225 Engine)**....
Check Brake Operation and Pedal
Free
Play X Check
Clutch
Pedal
Free
Play. .... X
Check all
V-Belt
Tensions X
Check Exhaust Emission System
(If
so equipped)*** \ X
Service Positive
Crankcase
Vent
Valve
and Breather . .' X
Road Test
Including
a Check of all Instrument
Lights
and Controls X Tune-up Engine
Check Operation of
Manifold
Heat
Control
Valve

Clean
Exterior of Radiator

Align
Headlights • Check Brake
Linings
,
Check Exhaust System for Leaks Replace Canister Air
Filter
(F. E. E. C. System)
Check
Axle
U-Bolt
Torque. Check Lubricaunt
Level
of Front
Axle
Universal Joints
Check Shock Absorber Mountings and Bushings Check Front and
Rear
Spring Bushings

Lubricate
Distributor
(V6-225).
Replace Spark, Plugs
Check Charging and Starting Circuits
Lubricate
Tailgate Latch, Supports and Hinges.

Lubricate
Door and
Hood
Hinge Pivots ;
Lubricate
Glove Compartment Door Latch

Lubricate
Heater Controls •

Lubricate
Windshield
Wiper and Washer Controls
Clean,
Repack and
Adjust
Wheel Bearings
Change Transmission and Transfer Lubricant. .
Replace
Dry-Type
Air Cleaner • Check Lubricant
Level
of
Differential

Lubricate
Transfer
Case
Shift
LeArer
Control
C«se.
. , . . . . . . . .
Continuing
each
2,000 miles

Continuing
each
6,000 miles

Continuing
each
24,000 miles

X
Continuing
each
30,000 miles
•Check after the
first
200 miles [320
km.
J
of operation.
If
wheel or wheels are changed for any
reason,
have
wheel nut torque rechecked after an additional two hundred miles of operation
••Service mileage shown or every 60 days, whichever occurs
first.

•••Maintenance check on emission system must be performed per
information
in this manual. "See text for brakes.

"Nj
^Miles
2,000
6,000
12,000
18,000
24,000
30,000
Kilometers

3,200
9,600
19,200
28,800
38,400 48,000

B-9.
Engine Oil

For
maximum
engine
protection under all driving conditions encountered during the recommended

oil
change intervals, it is necessary to use only

"MS"
certified
sequence-tested
oils. The term
"MS"
must appear on the oil container singly or

in
conjunction with other designations. "MS" des­
ignated oils are heavy-duty detergent oils that are
formulated to withstand all service conditions in
modern powerplants. Engine oils designated only
as
"ML"
and/or
"MM"
are not recommended and should not be used except in an emergency when

"MS"
oil is not available. Certified
sequence-tested

engine
oils are described on their containers by

such
phrases as:
meets,
exceeds,
excels, or has
proven superior in the
test
requirements,
test
sequences, MS Service
tests,
standards, and service

requirements,
of automotive manufacturers, auto­
makers,
or car manufacturers for MS service or
Service
MS.
It
may be necessary to change
engine
oil more
frequently than normally recommended, depending upon the type and quality of oil used, the severity
of operation conditions, if the
engine
is used for
short
periods in cold weather, or if the
engine
is allowed to idle for excessive periods.

Always
drain
the crankcase while the
engine
is hot since
dirt
and contaminants are then more
likely
to be held in suspension and therefore
will

drain
out more completely.
Drain
the crankcase as follows:

a.
Position the
drain
receptacle under the
drain

plug.

b.
Remove the
drain
plug using the correct size

wrench.
Be careful of hot oil.
c.
Carefully
clean the
drain
plug. Inspect and

replace
the gasket, if deteriorated.
d.
When the oil has drained, replace and tighten
the crankcase
drain
plug. 12

B

LUBRICATION
Note:
Hard
shifting of the transmission gear in
cold weather is a positive indication that the
lubri­

cant
is of the wrong viscosity or of poor quality

which
allows it to congeal.

B-38.
Optional
4-Speed
Transmission
and
Transfer Case

The
four-speed transmission and transfer case re­

quire
separate lubrication for each unit as
they
have no cross-over oil passage. At each transmission
service check, the
fill
plugs of
both
four-speed

transmission
and transfer case should be pulled
and
the lubricant refilled to level if necessary.

B-39.
Transfer
Case
Linkage

The
transfer case shift linkage should be lubricated

periodically.
All
bearing surfaces that are assembled
with
studs and cotter pins should be disassembled, cleaned, and coated with a
good
waterproof grease.

The
bearing surfaces that cannot be disassembled
should be lubricated with a lubricant that
will
penetrate the bearing
area.
These bearings include
the two on the cross shaft assembly and the
threaded stud.

The
type
of penetrating lubricant recommended is
DuPont
"PM 7", No. 2911, or its equivalent.

B-40.
Brake Master Cylinder

Clean
the top of the
fill
cap and also the housing

area
around it. Remove the cap and observe the
fluid
level. It should be
half
an inch
below
the top
of the fill-hole. If not, add brake fluid to
half
inch
[1,3 cm.]
below
the top of the fill-hole. Use
only heavy-duty brake fluid conforming to speci­
fication
SAE-J-1703.
Be sure to handle the brake

fluid
in clean dispensers and containers that
will
not introduce even the
slightest
amount of other

liquids
or foreign particles. Replace and tighten
the
fill
cap.

B-41.
Adjust Brakes

Refer
to Section P.
B-42.
Brake Linings

Refer
to Section P.

B-43.
Adjust Clutch

Refer
to Section I.

B-44.
Clutch Cross Shaft (Lever Type)

Lubricate
the clutch cross shaft in accordance with
specifications given in the
Lubrication
chart: see
Item
1. Chassis Bearings.

B-45.
Tie Rod and Drag
Link
Sockets

The
tie rod and drag
link
sockets
are equipped

with
lubrication
fittings
and should be lubricated

per
specifications given in the
Lubrication
chart: see Item 1. Chassis Bearings.
B-46.
Front
and
Rear Spring
Bushings

The
condition of the spring bushings is indicated
by the alignment of the spring pivot and spring
shackle
bolts.
Check
the alignment of
these
bolts,

and
check that nuts are
tightened
securely.

B-47.
Spring
Shackles

Rubber
bushings are provided on the spring
shackles.
These rubber bushings have no lubrication
fitting and it is very important that
they
never be lubricated.

B-48.
Shock Absorbers

Visually
check for broken mounts or bolts, worn

or
missing bushings on the shock absorbers. Refer
to Section S.

B-49.
Front and
Rear
Axle
U-Bolts

Torque
the front and
rear
axle U-bolts. Refer to Section S.

B-50. Front
and
Rear
Axle
Differentials
—
Lubricant Levels

The
lubricant
level of all front and
rear
differentials should be at the level of the fill-hole.

B-51.
Front and
Rear
Axle
Differentials
—
Changing
Lubricant
B-52.
Conventional Differentials

To
remove the lubricant from the front or
rear
differential,
it is necessary to remove the housing cover. Let the lubricant
drain
out, and then flush
the differential with a flushing oil or light
engine

oil
to clean out the housing
(except
Powr-Lok
or
Trac-Lok
Differentials). Do not use water, steam,
kerosene, or
gasoline
for flushing.

Reinstall
the housing cover, replacing the gasket whenever necessary, torquing the cover
bolts
to 15 to 25 lb-ft. [2,1 a 3,4 kg-m.].
Remove the filler plug, and
refill
the differential
housing as specified in the
Lubrication
Specifica­
tions.

B-53.
Powr-Lok
or
Trac-Lok Differential

Some vehicles may be equipped with the
Powr-Lok

or
Trac-Lok
Differential as optional equipment.
Special
lubricant and ordinary multipurpose gear

lubricants
must
not be used. Use only
'Jeep*
Differ­

ential
Oil,
Part
No. 94557.

Powr-Lok
or
Trac-Lok
differentials may be cleaned
only by disassembling the unit and wiping with
clean
rags. Do not flush the unit. Refer to Sec­
tion N.

B-54.
Front Axle Universal Joint
—
Lube

Check
the level of the front axle universal joint
lubricant
at each front wheel by removing the
fill-hole plug. The lubricant should be level with
the fill-hole. If required, add lubricant as specified

in
Lubrication
Specifications.

B-55.
Front
Axle
Universal
Joint
— Service

On
all 4-wheel drive vehicles the front axle
uni­

versal
joint should be serviced by removing the shaft and thoroughly cleaning the universal joints

and
housing. For the correct procedures, refer to
Section M. 16

'Jeep'
UNIVERSAL SERIES SERVICE
MANUAL

D
Remove the screws and lockwashers that attach
the main bearing caps to the cylinder block. Use
a
lifting bar beneath the ends of each bearing cap.

Be
careful not to exert too much pressure to cause
damage to the cap or
dowels
and pry the caps free.

CAUTION:
If main bearing caps are not removed
carefully
by raising both sides of each cap evenly

until
free of the dowels, the
dowels
may be bent.

A
bent main bearing cap dowel can cause misalign­ ment of the cap and resultant
rapid
bearing wear
necessitating replacement. Therefore, remove each
main
bearing cap carefully. If there is reason to
believe any of the
dowels
have been bent during
the bearing cap removal, remove them and install
new
dowels
as detailed in Par. D-34c.
Remove the upper
half
of the
rear
main bearing

oil
seal from the cylinder block and the lower
half

from
the oil seal
groove
in the
rear
main bearing

cap.
Install
the main bearing caps and bearings on
the cylinder block in their original positions.

Note;
Removal of the crankshaft may be ac­
complished only with the
engine
out of the vehicle.

D-27.
Remove
Exhaust
Valves and Springs
Access to the valve chamber is obtained by re­ moving the attaching parts and the valve spring
cover and gasket from the cylinder block. Use cloths
to block off the three
holes
in the exhaust valve
chamber to prevent the valve retaining locks falling
into the crankcase, should they be accidentally dropped.

With
a valve
/
spring compressor, compress the valve springs on
those
valves which are in the
closed position (valve seated against cylinder

block).
Remove the exhaust valve spring retainer

locks,
the exhaust valve spring retainer, and the exhaust valve spring. Close the other valves by
rotating the camshaft and repeat the above opera­
tion for the other valves in the same manner.
Lift

out all the exhaust valves and tag or place them in
a
rack
to indicate the location where each was re­moved from the cylinder block. If a valve sticks in
the guide and cannot be easily lifted out,
pull
the valve upward as far as possible and remove the

spring.
Lower
the valve and remove any carbon

deposits
from the valve stem.
This
will
permit re­ moval of the valve.

For
intake valve and spring removal, see
Par.
D-l7.

D-28.
Remove Camshaft

a.
Push the intake and exhaust valve tappets into the cylinder block as far as possible so the ends of
the tappets are not in contact with the camshaft. b. Secure each tappet in the raised position by in­
stalling a common clip-type clothes pin on the

shank
of each tappet or tie them up in the valve
chamber.

c. Remove the camshaft thrust plate attaching
screws.
Remove the camshaft thrust plate and

spacer.

d.
Pull
the camshaft forward out of the cylinder
block using care to prevent damage to the cam­
shaft bearing surfaces.
D-29.
Remove Valve Tappets
Remove the intake and exhaust valve tappets from
the
bottom
or crankshaft side of the cylinder block
after the camshaft has been removed. Tag each
tappet or place them in a marked
rack
so they may be reassembled in their original positions.

D-30.
Remove Oil
Gallery
Plugs
Remove the plug at each end of the oil gallery in the cylinder block.
This
operation is only applicable
when the
engine
is out of the vehicle and
will
allow access to the oil gallery so it may be cleaned.

D-31. ENGINE INSPECTION
AND
REPAIR
The
inspection and repair procedures detailed here­

in
are recommended to be followed when a com­
plete
engine
overhaul is to be made with the
engine

out of the vehicle. These instructions can generally be applied individually with the
engine
in the
vehicle. Wherever the procedure differs due to
the
engine
being in the vehicle, the necessary

special
instructions are provided. Inspection 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.

Important:
Before the inspection and repair pro­
cedures listed below are begun, the
engine
serial
number must be checked for the presence of
code

letters denoting undersize bearings or oversize
pistons. Refer to Par. D-2.

D-32.
Cylinder
Block

The
cylinder block must be thoroughly cleaned, inspected and repaired as detailed in the following

paragraphs.

D-33.
Cleaning

The
cylinder block may be steam cleaned or cleaned

with
a suitable solvent. A scraper is recommended
to remove
hard
deposits, except on highly finished surfaces. Special attention must be directed to the
cleaning of the oil passages, valve chamber,
crank­

case, and cylinder walls to remove all sludge,
dirt

and
carbon deposits. After cleaning, use air pressure to dry the block thoroughly.
D-34. Inspection

Examine
the cylinder block for minute cracks and

fractures.
Rusted valve springs or evidence of rust

in
the valve chamber or the cylinder walls is a
good

indication of a possible
crack
in the block,

a.
Examine all machined surfaces of the cylinder block for
burrs
and scores.
Check
for cylinder block
distortion by placing a straight
edge
along the
length of the cylinder head surface of the block.
With
a feeler
gauge,
check for clearance
between
the straight
edge
and the block, particularly be­
tween adjacent cylinders. Maximum permissible
out of line for service is .010"
[0,254
mm.] over the
full
length of the block. 45

'Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL

D
straight
in the hole, then tap the dowel lightly

with
a hammer until it
bottoms.

d.
When installing bearing eaps, be sure to tighten
the
bolts
evenly in each cap to
pull
it into place
without bending the
dowels
or distorting the
bearing
cap.
e. Other parts of the block which require inspec­ tion
and
possible
repair,
but which are directly
related
to other
engine
components (such as tappets, pistons, camshaft, valves, crankshaft, and

oil
pump) are covered later in this section.

D-35.
Cylinder
Bores

The
cylinder bores may be reconditioned by honing
or
reboring. Use oil-soaked rags to protect
crank­

shaft
journals
and other
engine
parts from abrasive
dust during all reconditioning operations.

Both
honing and reboring of the cylinders must be
done
carefully to fit the pistons and to obtain
specified clearances. If reboring of the cylinder bores is not required but the walls are glazed, use

a
finishing
hone
to remove the glaze. Reboring the cylinders must not be attempted unless ade­
quate facilities and experienced service technicians
are
available. The amount of material to be re­moved is determined from the original diameter
of the cylinder bores (3.125" to 3.127") [79,375 a
79,426
mm.] plus the amount of oversize in diameter
of the oversize pistons to be fitted. Pistons are
available
in the following oversizes.
.010"
[0,254
mm.] .030" [0,762 mm.] .020" [0,508 mm.] .040" [1,016 mm.}

The
largest cylinder bore
will
determine the over­
size to which all cylinders must be rebored, since the size and weight of all pistons must be uniform
to maintain proper
engine
balance. The maximum rebore should not exceed .040" [1,016 mm.] from

standard.
Measure
the cylinder diameters by making mea­
surements both parallel to and at right angles to
crankshaft
over entire piston travel and at
bottom

of cylinder. Proceed as follows:

a.
If bores are scored; if out-of-round
exceeds
.005
"
[0,127 mm.]; if diameters differ more than .005";

or
if taper
exceeds
.005
"
on diameter, it is generally
recommended that cylinders be reconditioned by
reboring
and honing to the next oversize using new
pistons of the proper size.

Note:
If reboring is performed, allow .0015"
[0,0381
mm.] for final honing.

All
cylinder bore diameters must be within .002
"
[0,0508
mm.] after reconditioning.

b.
If bore measurements are within the above

limits,
but indicate hollows or waviness, cylinders should be honed with 250 grit
stone
hone. Pump
hone
up and down in cylinder while it is rotating
to produce a satin-finish, diamond cross-hatched

pattern
approximately 30° with horizontal. Hone
only enough to correct waviness.
c. If cylinder bore correction is unnecessary, break the glaze on cylinder walls with a 250 grit
stone

hone
or with a suitable deglazing tool. Operate the
hone
or deglazer to obtain diamond cross-hatched

pattern
previously mentioned.

d.
Regardless of type of correction on cylinder
walls,
wash out bores thoroughly afterwards and
apply
a light coat of
engine
oil. If cylinders have
been rebored or honed heavily, measure cylinder
diameters again to assure proper selection of piston
size.

D-36.
Pistons, Rings, and Connecting Rods
Pistons are each fitted with three rings, two com­ pression rings and one oil control
ring.
The pistons have an extra
groove
above the top ring which acts as a heat dam or insulating
groove
to protect
against sealing of the top ring in the ring
groove

with
hard
carbon. The piston pin is secured by the lock screw.

The
pistons and connecting rods were removed from
the
engine
as assemblies. If cylinders were rebored,
new oversized pistons and rings
will
have to be in­

stalled.

Disassemble the pistons and rods. Remove the
two compression rings, the oil control
ring,
and the oil control ring expander from each piston. Do not remove the
bolts
from the lower end of the
connecting rods unless the
bolts
are damaged.
Clamp
each connecting rod and piston assembly

in
a padded bench vise and remove the piston pin

lock
screw and lockwasher. Press the piston pin
out of the piston and connecting rod.
Clean
all
carbon,
gum, and lacquer
deposits
from both the

inner
and outer surfaces of each piston, connecting

rod,
and piston pin. Use a ring
groove
cleaner or a
broken
ring filed to a sharp square
edge
to clean
the carbon from the piston ring
grooves
and the

insulator
groove. Use care not to scrape metal from
the sides of the
grooves
or make
burrs
on ring
groove
surfaces. Run a length of wire through the

oil
spray
hole
near the lower end of the connecting

rod
to clear the
hole
of hardened oil
deposits
or
foreign matter.
Carefully
inspect the pistons and
replace
any that are broken or cracked. Replace
pistons if any of the ring lands are chipped, broken,
or
rounded on the
edges;
or if the piston is scored,

scratched,
or burned so seriously that the imperfec­
tions cannot be removed with a hand honing
stone

or
crocus cloth.

Replace
the pistons as follows:

a.
After cylinder bores have been carefully checked for out-of-round and taper (Par. D-35), check fit
of each piston to cylinder bore with block and
pistons clean and dry and at approximately 70
°F.
[21°C]
by using Piston Fitting Gauge And Scale

Tool
No. C-690 as shown in Fig. D-7. Use a .003"
[0,0762
mm.] thickness
gauge
%" [19 mm.] wide.

The
piston is fitted upside down in the block to
facilitate the operation. The
gauge
must extend the
full
length of the piston on the thrust side
(opposite

side from slot in piston
skirt).
Scale should register
5
to 10 pounds [2,3 a 4,5 kg.]
pull
to remove the
thickness
gauge
from
between
cylinder
wall
and piston. Excessive
pull
indicates need for a slightly

smaller
piston or additional honing of cylinder. In­ sufficient
pull
indicates need for fitting a larger piston. 47

D

HURRICANE
F4
ENGINE

FIG.
D-7—PISTON
FITTING
b.
Check
and if necessary correct connecting rod
alignment using a connecting rod aligning fixture,

such
as the one shown in Fig. D-8, in accordance
with
the instructions furnished with the fixture.

c.
Check
the piston pin fit. The piston pins are fitted
with
a clearance of .0001" to .0003" [0,0025

a
0,0076
mm.] which approximates a light thumb
push
fit at room temperature. See Fig. D-9. The piston pins are anchored in the rods with lock

screws.
Installation of oversize pins in this
engine

is not recommended as experience has shown that
should a pin be worn sufficiently to require replace­ ment, the piston should also be replaced.

Clamp
the connecting rod in a vise using
jaw
shields
of
soft
metal or two pieces of hardwood, one on
each side of the rod and positioned approximately
3" [76 mm.] from the piston pin end.
Start
,
.. . | 10278 j

FIG.
D-8—CHECKING
CONNECTING
ROD
ALIGNMENT
1
—Feeler
Gauge
2—Fixture
FIG.
D-9—PISTON PIN
FITTING

the piston pin in the piston with the lock

screw
groove
facing down. Assemble piston to connecting rod with the piston
skirt
T-slot on
FIG.
D-10—CONNECTING ROD AND
PISTON

1—
Oil
Spray
Hole

2—
Piston
Skirt
T-slot

3—
Relative
Position
of
Camshaft

48

-Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL

E>
[5,928 a
5,926
cm.] for all main bearings. Allowable
taper or out-of-round of the journals is .001"
[0,0254
mm.].

D-42.
Checking Connecting Rod
Crankpins

Check
the crankpin diameters with a micrometer
to ensure that they are not out-of-round or tapered more than .001"
[0,0254
mm.] The standard
crank-

pin
diameter is
1.9383*
to
1.9375"
[4,9233
a
4,9213

cm.].
D-43.
Crankshaft
Main
Bearings

The
crankshaft rotates on three main bearings

with
a running clearance of .0003" to .0029"
[0,0076
a
0,0736
mm.].

These
bearings are positioned and prevented from
rotating in their supports in the cylinder block by
dowel pins. Dowel pins are used in both the center

and
the
rear
bearing caps. No dowel pins are used

in
the front bearing cap because the bearing has
a
flange. The front main bearing takes the end

thrust
of the crankshaft. The main bearings are of premium type which provides long bearing life.
They
are replaceable and when correctly installed, provide proper clearance without filing, boring,

scraping,
or shimming. Crankshaft bearings can
be removed from this
engine
only with the
engine

out of the vehicle. Crankshaft bearings must be replaced as a complete set of three bearings, each
bearing consisting of two halves.
Main
bearings
are
available in the standard size and the following
undersizes:
.001" [0,025mm.] .012" [0,305 mm.] .002" [0,051mm.] .020" [0,508 mm.] .010" [0,254mm.] .030" [0,762 mm.]

The
.001" and .002" undersize main bearings are
for use with standard size crankshafts having
slightly worn
journals.
The .010", .020", and .030" undersize bearings are for use with undersize

crankshafts
in
those
sizes. The .012" undersize
bearings are for use with .010" undersize
crank­
shafts having slightly worn journals. Bearing sizes

are
rubber stamped on the reverse side of each
bearing half.
D-44. Crankshaft
Main
Bearing Inspection

The
crankshaft
journals
must be carefully inspected
as detailed previously in Par. D-41. Worn journals

will
require undersize bearings. Scored, flaked, or

worn
bearings must be replaced. Measure the main
bearing bores in the cylinder block using a
telescope

gauge
and micrometer. Measure the bores at right
angles to the split line and at 45° to the split line.

The
bores should not be over .001"
[0,0254
mm.]
out-of-round or .001" in taper from end to end.

Also,
the bores should not be more then .001"
oversize, considering the average diameter of the
bore.

D-45.
Fitting Crankshaft
Main
Bearings
Using
Plastigage

After
wiping and carefully inspecting the bearing bore, install the proper bearing. See that the oil

hole
in the bearing upper half registers properly

with
the oil
hole
in the block, and that the bearing
lock fits properly in the notch in the block.
Install

the crankshaft if replacing bearings with the
engine

out of the vehicle. The desired running fit (dif­
ference
between
the diameter of the crankshaft

journal
and the inside diameter of the fitted bear­ ing) for a main bearing is .0003" to .0029"
[0,0076

a
0,0736
mm.]. With a dimension in
excess
of this
standard
running fit, a satisfactory bearing replace­ment cannot be made and it
will
be necessary to

regrind
the crankshaft.
Install
the bearing lower

half
and the bearing cap and draw the nuts down
equally and only slightly tight. Rotate the
crank­

shaft by hand to be sure it turns freely without

drag.
Pull
the nuts tighter, first one then the other,
a
little at a time, intermittently rotating the
crank­

shaft by hand until the recommended torque of
35 to 45 lb-ft. [4,8 a 6,2 kg-m.] is reached. If the
bearings are of the correct size, and lubricated with
light oil before installation, the crankshaft should
turn
freely in the bearings. If the crankshaft cannot
be turned, a larger bearing is
required.
If there is no binding or tightness, it is still necessary to check
clearance to guard against too
loose
a fit. 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 bearing half. The use
of "Plastigage" of the proper size to measure .001" [0,025 mm.] clearance is recommended for check­
ing crankshaft main bearing clearance. The method
of checking clearance is as follows:

a.
Remove the bearing cap and carefully wipe

all
oil from the bearing and the
journal.
b.
Lay a piece of "Plastigage" y%" [3 mm.]
shorter than the width of the bearing across the

journal
(lengthwise of the crankshaft).

c.
Install
the bearing and cap and tighten first
one nut, then the other, a little at a time to the specified torque. As the bearing
tightens
down

around
the
journal,
the "Plastigage" flattens to a
width that indicates the bearing clearance.

d.
Remove the cap and measure the width of
the flattened "Plastigage," using the scale printed
on the
edge
of the envelope. The proper size "Plasti­
gage"
will
accurately measure clearance down to .001".
e. If the flattened "Plastigage" tapers toward the middle, or toward the end, or both ends, there
is a difference in clearance, indicating a taper, a
low
spot,
or other irregularity of the bearing or

journal.

D-46.
Fitting Crankshaft
Main
Bearings
Using
Shim Stock

Thin
feeler or shim stock may be used instead of "Plastigage" to check bearing clearances. The
method is simple, but care must be taken to protect
the bearing metal surface from
injury
by too much pressure against the feeler stock,

a.
Cut a piece of .001" [0,025 mm.] thick, by Yl [12,7 mm.] wide, feeler stock }4" [3 mm.]
shorter than the width of the bearing. Coat this 51