seats JEEP CJ 1953 Service Manual

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

C

FIG.
C-22—-CHECKING
FUEL
PUMP
PRESSURE
—
DAUNTLESS
V-6
ENGINE a
couple of strokes to be sure the pump is primed.

Using
a half-pint
bottle
or similar measure, pump
Vi
pint [0,24 It] of fuel by cranking the
engine

with
the starter motor. Count the strokes neces­
sary
to
fill
the measure. If more than 20 strokes

are
required, the fuel pump is inefficient, the tank
line is leaking air, or the fuel supply is restricted.

Check
fuel filter in the fuel tank if line is restricted.

C-24.
Check Manifold Vacuum

To
check the intake manifold vacuum on the
Hurri­

cane F4 engine, remove the ventilation valve and

L
fitting from the manifold and install special adapter. On the Dauntless V-6
engine
remove the
pipe plug located in the right
rear
of the intake
FIG.
C-23—CHECKING MANIFOLD VACUUM
—

HURRICANE
F4
ENGINE
manifold and install special adapter. Connect the

vacuum
gauge
tube to the special adapter as shown

in
Fig. C-23 for the
Hurricane
F4 engine.

Start
the engine. Connect a Tachometer
Tool,

C-3896,
from the distributor
primary
terminal to ground and set the
engine
speed at the specified

rpm.
given in Par. C-30. Observe the vacuum
read­

ing and interpret as follows:

a.
A steady reading from 18" to 20" [457 a 508
mm.] of mercury is a normal reading, indicating
that valve and
spark
timing, valve seating, and
piston ring sealing are all satisfactory.
b. A steady but below normal reading indicates

a
condition common to all cylinders such as a

leak
at the carburetor gasket, late ignition or valve
timing, or uniform piston ring and bore wear.

c.
A slowly fluctuating or drifting reading in­ dicates that the carburetor idle mixture is incorrect

Look
for the cause in the fuel system.

d.
A rhythmic pulsating reading is caused by a
condition affecting one or more cylinders, but not

all,
and indicates leaky valve, gasket blowby, re­
stricted intake port, or an electrical miss.
e. An intermittent pulsating reading is caused by

an
occasional malfunction, such as a sticking valve
(all
valves may be
erratic
in operation if the valve
springs are weak), electrical miss caused by insuffi­
cient distributor point tension or low coil
voltage

coupled with inconsistent
spark
plug
gaps
or fouled
plugs, or
dirt
in the fuel system finding its way into
passages of
critical
size or valve
seats
in the
car­

buretor.

f.
A normal reading that quickly falls off (with

engine
running at
2000
rpm.) indicates exhaust
back
pressure caused by a restriction in the exhaust
system.

g.
Make indicated corrections to bring vacuum to 18" to 20" [457 a 508 mm.] of mercury normal

reading.

C-25.
Carburetor Adjustments

•
Refer to Fig. C-24, C-25 and C-26.

Carburetor
adjustments should not be attempted

until
it is known that
engine
ignition and com­
pression are in
good
order. Any attempt to adjust

or
alter the carburetor to compensate for faulty conditions elsewhere
will
result in reduced econ­
omy and overall performance.

Caution:
If an
engine
is idling too slow or rough,
this may be caused by a
clogged
ventilator valve

or
hose;
therefore, never adjust the carburetor idle
without first checking the crankcase ventilator
check valve and
hose.

The
air cleaner must be left in place while making
idle speed and mixture adjustments. All lights and accessories, must be turned off. The positive
crank­

case ventilator system should also be in
good
oper­
ating condition when making carburetor adjust­ ments.
Either
of
these
items noticeably affects the

air
fuel ratio at idle.

•
Hurricane
F4 Engine.
Note:
The idle mixture adjustment procedure for
the late model
YF-4941S
and
YF-6115S
Carter

31

TUNE-UP

C-29.
SERVICE
DIAGNOSIS

POOR
FUEL ECONOMY Ignition Timing Slow or Spark Advance Stuck

Carburetor
Float High
Accelerator Pump Not Properly Adjusted High Fuel Pump Pressure

Fuel
Leakage

Leaky
Fuel Pump Diaphragm Loose Engine Mounting Causing High Fuel Level in Carburetor

Low
Compression
Valves Sticking
Spark
Plugs Bad

Spark
Plug Cables Bad
Weak
Coil
or Condenser Improper Valve Tappet Clearance

Carburetor
Air Cleaner Dirty
High Oil Level in Air Cleaner Dragging Brakes

Front
Wheels Out of Alignment

Tires
Improperly Inflated Inaccurate Odometer

Faulty
Fuel Tank Cap
Clogged
Muffler or Bent Exhaust Pipe Sticking Exhaust Manifold Valve

LACK
OF POWER
Low
Compression Ignition System (Timing Late)
Improper Functioning Carburetor
or Fuel Pump

Fuel
Lines
Clogged

Air
Cleaner Restricted Engine Temperature High Improper Tappet Clearance
Sticking Valves
Valve Timing Late

Leaky
Gaskets
Muffler
Clogged

Bent Exhaust Pipe Sticking Exhaust Manifold Valve —
Dauntless V-6 Engine

LOW
COMPRESSION
Leaky
Valves Poor Piston Ring Seal Sticking Valves
Valve Spring Weak or Broken
Cylinder
Scored or Worn
Tappet Clearance Incorrect Piston Clearance too Large

Leaky
Cylinder Head Gasket

BURNED
VALVES AND SEATS Sticking Valves or too Loose in Guides
Improper Timing
Excessive Carbon Around Valve Head and Seat Overheating
Valve Spring Weak or Broken
Valve Tappet Sticking
Valve Tappet Clearance Incorrect
Clogged
Exhaust System

Defective
Valve
Lifter
— Hydraulic
VALVES
STICKING
Warped Valve Improper Tappet Clearance Carbonized or Scored Valve
Stems

Insufficient Clearance Valve Stem to Guide
Weak or Broken Valve Spring Valve Spring Cocked Contaminated Oil

OVERHEATING
Inoperative Cooling System
Theromstat Inoperative Improper Ignition Timing
Improper Valve Timing
Excessive Carbon Accumulation
Fan
Belt too Loose

Clogged
Muffler or Bent Exhaust Pipe
Oil
System Failure Scored or Leaky Piston Rings
Sticking Exhaust Manifold Valve — Dauntless V-6 Engine

POPPING-SPITTING-DETONATION
Improper Ignition Improper Carburetion
Excessive Carbon
Deposit
in
Combustion Chambers
Poor Valve Seating Sticking Valves
Broken Valve Spring Tappets Adjusted too Close
Spark
Plug Electrodes Burned
Water or Dirt in Fuel
Clogged
Lines Improper Valve Timing

Clogged
Fuel Filter Sticking Exhaust Manifold Valve —
Dauntless V-6 Engine

EXCESSIVE
OIL CONSUMPTION Piston Rings Stuck in Grooves, Worn or Broken Piston Rings Improperly Fitted or Weak Piston Ring Oil Return
Holes
Clogged

Excessive Clearance, Main and
Connecting Rod Bearings

Oil
Leaks at Gaskets or Oil Seals
Excessive Clearance, Valve Stem
to Valve Guide (Intake)

Cylinder
Bores Scored, Out-of-
Round or Tapered
Too Much Clearance, Piston to Cylinder Bore
Misaligned Connecting Rods
High Road
Speeds
or Temperature
Crankcase
Ventilator Not Operating

BEARING
FAILURE
Crankshaft
Bearing Journal Out-of-Round

Crankshaft
Bearing Journal Rough

Lack
of Oil
Oil
Leakage

Dirty
Oil

Low
Oil Pressure or Oil Pump Failure

Drilled
Passages
in Crankcase or Crankshaft
Clogged

Oil
Screen Dirty
Connecting Rod Bent 34

D

HURRICANE
F4
ENGINE
against the hub of the crankshaft pulley.
Timing

gears are accessible for inspection or replacement

with
the
engine
installed in the vehicle after re­ moving the radiator, belt drive pulley, and timing
cover.

Should
it be necessary to replace the timing gears, attention must be given to the end float of both
the camshaft and crankshaft and to the running

clearance
of both gears. It is also advisable to
check
both the oil jet and oil passage to the
crank­

shaft front bearing to be sure that they are clear.

D-55.
Inspection and
Repair

Check
the general condition of both gears and
inspect for evidence of excessive wear. Replace
excessively worn or damaged gears. Inspect the
cover and replace if bent or damaged. It is recom­ mended that the crankshaft oil seal in the cover
be replaced when the cover is removed to ensure a
good
seal around the crankshaft. To replace this

seal
with the
engine
in the vehicle
requires
removing
the radiator and water pump.

D-56.
Valves, Springs, and Guides

The
exhaust valves seat on the top of the cylinder

block
with the
stems
extending down through
replaceable valve guides. The exhaust valves are actuated by the camshaft through exhaust valve
tappets. The exhaust valve springs are assembled

and
locked on the lower end of the exhaust valve
stems. The retaining locks are the split type, which
fit in a recess on the valve
stems
and into the taper

in
the valve spring retainers.

Adjustment
of exhaust valves is by means of the
adjusting
screw threaded into the upper end of the
exhaust valve tappets. An exhaust valve rotator used as a valve spring retainer is installed on the
lower end of the exhaust valve.
This
valve rotator,
known
as "Roto Cap", is a spring-loaded
ball

bearing
device. On each lift, or opening stroke of
a
valve, the rotator
gives
the valve a slight positive
clockwise rotation.

The
intake valves operate in valve
guides
in the
cylinder
head and are actuated by rocker arms.

The
rocker arms are actuated by valve push rods

and
the intake valve tappets. The intake valve
springs,
the intake valve spring retainers, and the

intake
valve spring retainer locks make up the

remainder
of the valve operating parts. An intake
valve spring retainer oil seal which encircles the

upper
end of the intake valve
between
the valve
locks and the upper end of the valve spring re

tainer,
controls the passage of oil along the valve
stem and guide.

Note:
When
engine
trouble indicates defective
valves as a possible source of trouble, also check

all
vacuum line connections for possible leaks.

D-57.
Inspection of Valves, Springs,
and
Guides

Clean
the valves on a wire wheel, making sure that

all
carbon is removed from the top and the under­
side of the heads and that all gum and varnish
deposits
are removed from the stems.
Polish
the valve
stems
with steel wool or crocus

cloth.
Visually
inspect all valves for warpage,

cracks,
or excessive burning and discard if one of

these
conditions exists. Replace any worn, pitted,

or
corroded valves that cannot be cleaned with a
wire
brush.
Replace any valves when
seats
are pitted, burned, or corroded so badly that they
cannot be cleaned up with a light refacing on a valve refacing machine.

Replace
valves with marks of scoring or abrasion visible on the stem. Replace any valves with bent

stems
which
will
be apparent when the valve is
mounted in the valve refacing machine.

Note:
Use only hard-face exhaust valves for
replacement.

Examine
the
stems
of valves which employ the
ball
bearing rotators.
Wear
marks around the
cir­

cumference of the
stems
indicates that the valve is
rotating satisfactorily.
Vertical
heavy pressure

areas
indicate that the valve is not rotating and the valve spring retainer (Roto
Cap)
should be replaced

if
at fault.
Check
the diameter of the valve stem at two or three places along the length of the stem

with
a micrometer. The intake valve stem diameter is .3733" to .3738" [9,482 a
9,495
mm.]. The
exhaust valve stem diameter is .371" to .372"
[9,423
a
9,449
mm.].

Note:
Exhaust
and intake valve springs are

similar
in appearance. They must not be inter­
changed as they have different spring
charac­

teristics.

Wash
the valve springs thoroughly in solvent.

Visually
examine the springs and replace any that

are
deformed or obviously damaged. Examine for

corrosion
from moisture or acid etching which might
FIG.
D-19—TESTING
VALVE
SPRING

1—
Torque
Wrench

2—
Spring
Testing
Fixture

3—
Valve
Spring
54

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

develop
into surface cracks and cause failure.

Measure
the over all free length of the springs and
replace any that do not measure to standard: 1%" [35,7 mm.] for intake valve springs and 2j^"
[63,5 mm.] for exhaust valve springs. If possible,
check each valve spring in a valve spring testing
fixture C-647 or equivalent as shown in Fig. D-l9.
Test
each spring when compressed to the two
different spring lengths given (representing valve closed and valve open spring length). If any spring
fails to register spring tension equal to or greater
than
the minimum load limit in pounds specified for that spring length, replace the spring.

Length
Minimun
Load

Intake
valve spring. . .
1.660"
[4,216 cm.] 66 lb. [29,9 kg.]
1.400"
[3,556 cm.] 140 lb. [63,5 kg.]

Exhaust
valve spring. 2.109" [5,356 cm.] 47 lb. [21,3 kg.]
1.750"
[4,445 cm.] 110 lb. [49,9 kg.]

Note:
When using a spring checking fixture C-647

or
equivalent as shown in Fig. D-l9, it is necessary
to convert the torque wrench reading which is in pounds-feet to the static pound pressure specified above according to the instructions furnished with
the wrench. For example, should the torque wrench reading be 50 lb-ft. and the wrench is two
feet
long
the static pressure of the spring
will
be 50 x 2 or 100 lbs.

Clean
the valve
guides
with a standard valve guide
cleaner or a wire
brush.
Check
the valve
guides
in the cylinder block. Replace valve
guides
which are

broken
or worn enough to cause excessive valve

stem-to-guide
clearance. See Par. D-61.
Standard
intake valve clearance is .0007" to .0022"

[0,0178
a
0,0559
mm.] and the exhaust valve
clearance is .0025" to .0045" [0,0635 a
0,1143
mm.].

Excessive
clearance
between
the valve
stems
and
guides
will
cause improper seating and burned
valves. When there is a tendency to draw oil vapor
through the guide causing excessive oil consump­ tion, fouled
spark
plugs, and poor low-speed per­
formance. To check the clearance of the valve stem
to the valve guide, take a new valve and place in
each valve guide.
Check
the clearance with a
suitably mounted
dial
indicator or feel the clearance by moving the valve stem back and forth. If this
check shows excessive clearance it
will
be necessary to replace the valve guide.
D-58.
Refacing Valves

Re
face the valves with a valve refacer. The valve

refacer
manufacturer's instructions should be fol­
lowed carefully to ensure a valve face concentric

with
the valve stem. Reface both intake and ex­
haust valves to an angle of 46°.
Take
off only the
minimum
of metal required to clean up the valve faces.

If
the thickness of the
edge
of the valve head is
reduced to
less
than
J^>"
[0>8 mm.] replace the valve.

Note:
Cocked or deformed valve springs or im­

properly
installed or missing locks can be responsible
for valve problems.

D-59.
Valve Seat Inspection
and
Refacing

Inspect the valve
seats
for
cracks,
burns, pitting,
ridges, or improper angle.
During
any general

engine
overhaul it is advisable to reface the valve

seats
in both the cylinder block and head regardless
of their condition. If the valve
guides
are to be re­ placed, this must be
done
before refacing the valve
seats.
Note
that later
engines
have hardened
exhaust valve seat inserts.

Valve
seat inserts must be concentric with finish

ream
of valve stem
guides
(exhaust) within .002"
[0,051
mm.] total indicator reading.

When
necessary to reface the valve seats, use a
valve seat grinder in accordance with the grinder
manufacturer's
instructions. Any grinding of valve

seats
should be preceded by touching up the
grinding
stone
so that their angles are accurate and
the
stone
is not
clogged.
Grind
each valve seat to

a
true 45° angle. Never grind any more than is necessary to clean up pits, grooves, or to correct
the valve seat runout.
Check
the valve
seats
with
10465

FIG.
D-20—VALVE
WITH
ROTO
CAP
FIG.
D-21—GAUGING
VALVE
SEATS

55

D

HURRICANE
F4
ENGINE

FIG.
D-2
2—REFACING
VALVES
1—
Valve
Refacer

2—
Valve
a
dial
indicator as shown in
Fig.
D-21 after refacing.

The
valve seat should not be out of round more

than
.002"
[0,051
mm.]. A simple check can be
made in the absence of a
dial
indicator by spreading
a
thin coat of pencil lead or bearing-fitting blue on
the valve face and then inserting the valve into the valve seat.
With
hand pressure, rotate the valve

a
quarter
turn
and then remove the valve and ob­
serve the transfer of blue (or pencil lead) to the valve seat. An uneven transfer
will
indicate an

inaccurate
valve and valve seat refacing operation.

After
the seat is ground, check its width with a
seat width scale or a steel scale placed across the
face of the seat. The valve seat width after refacing
should measure [2,3 mm.] and not wider than
y%"
[3,2 mm.]. Valve seat width is
vital.
Too wide

a
seat can cause seat burning as it
tends
to trap

and
hold carbon particles. Seats that are too
narrow

will
not transfer heat to the coolant rapidly enough to keep the valves in proper operating condition.

When
a valve seat has been refaced several times

or
where it must be cut deeply for adequate recon­
ditioning, the seat may
become
too wide for efficient
operation. Narrow the seat without changing its
position in relation to the valve face by using a
valve seat relief counterbore above the seat and a valve seat narrowing cutter below the seat. These
operations are performed only after the valve
seats
have been refaced and then only when necessary.

The
finished valve seat should contact the approxi­mate center of the valve face.
Check
by applying

an
extremely thin coat of pencil lead or bearing-
fitting blue to the seat.
Then
install and rotate the
valve with light pressure. Blue (or pencil
marks)

will
transfer to the face of the valve. If the blue
is near the top
edge
of the valve face, lower the valve seat by using the valve seat relief counter-
bore. If the blue is transferred to the
bottom
edge

of the valve face, raise the seat by using the valve
seat narrowing cutter.

When
the valve seat can no longer be corrected, it
is advisable to investigate installing seat inserts.

D-60.
Exhaust
Valve Seat Insert Replacement

Hardened
valve seat inserts for exhaust valves
will

seldom require replacement. To avoid damaging the blcck, remove an insert with a tool designed for
this purpose.

When
installing a new insert, make certain the
counterbore is clean and smooth. Use a driver that

will
keep the insert in true alignment with the bore.

Cool
the insert and the installing tool with dry ice
for 30 minutes.

Note:
The insert should be sufficiently cooled
to permit installation with light taps; excessive

driving
of the insert may cock it in the counterbore

or
crack the insert.

Make
certain the valve seat is facing out.
Drive

in
the insert with the tool until it
bottoms
in the counterbore. After installation, grind the valve
seat at an angle of 45° and then check with a
dial

indicator
as shown in Fig. D-21.
D-61.
Valve Guide Replacement

Damaged,
loose,
or worn valve
guides
must be re­

placed.
Use valve guide driver W-238 or equivalent
to drive out the old guides. When replacing valve
guides, maximum
engine
performance can be se­

cured
only when the guide is positioned correctly
FIG.
D-23—VALVE
GUIDE
DRIVER

FIG.
D-24—VALVE
GUIDE
POSITIONS

1—Flush
at
this
point
2—One
Inch
[25
mm.
I

56

D

HURRICANE
F4
ENGINE
D-112.
SERVICE
DIAGNOSIS

Poor
Fuel
Economy Ignition Timing Slow or Spark Advance Stuck

Carburetor
Float High
Accelerator Pump Not Properly Adjusted
High
Fuel
Pump Pressure

Fuel
Leakage
Leaky
Fuel
Pump Diaphragm
Loose Engine Mounting Causing High
Fuel
Level

in
Carburetor

Low
Compression Valves Sticking

Spark
Plugs Bad

Spark
Plug Cables Bad Weak
Coil
or Condenser Improper Valve Tappet Clearance

Carburetor
Air Cleaner Dirty
High Oil Level in Air Cleaner Dragging Brakes

Front
Wheels Out of Alignment
Tires
Improperly Inflated Inaccurate Odometer

Faulty
Fuel
Tank
Cap

Clogged
Muffler or Bent Exhaust Pipe

Lack
of Power
Low
Compression Ignition System (Timing Late)
Improper Functioning Carburetor or
Fuel
Pump

Fuel
Lines
Clogged
Air
Cleaner Restricted
Engine Temperature High Improper Tappet Clearance
Sticking Valves Valve Timing Late

Leaky
Gaskets
Muffler
Clogged
Bent Exhaust Pipe

Defective
Spark Plugs—Clean or Replace
Defective
Breaker Points—Replace
Points

Incorrect Breaker Point Gap—Reset
Points

Defective
Condenser or Coil—Replace
Loose Electrical Connections—Locate and Tighten
Broken Valve Spring—Replace Spring Broken Piston or Rings—Replace
Defective
Head Gasket—Replace Gasket
Cracked
Distributor Cap—Replace Cap

Low
Compression
Leaky
Valves
Poor Piston Ring Seal Sticking Valves
Valve Spring Weak or Broken
Cylinder
Scored or Worn
Tappet Clearance Incorrect
Piston Clearance too Large
Leaky
Cylinder Head Gasket
Burned Valves and
Seats
Sticking Valves or too Loose in Guides Improper Timing
Excessive Carbon Around Valve Head and Seat Overheating
Valve Spring Weak or Broken Burned Valves and Seats—Continued
Valve Tappet Sticking
Valve Tappet Clearance Incorrect
Clogged
Exhaust System
Valves Sticking Warped Valve Improper Tappet Clearance
Carbonized or Scored Valve
Stems
Insufficient Clearance Valve Stem to Guide
Weak or Broken Valve Spring Valve Spring Cocked Contaminated Oil
Overheating Inoperative Cooling System
Thermostat Inoperative Improper Ignition Timing
Improper Valve Timing
Excessive Carbon Accumulation

Fan
Belt too Loose

Clogged
Muffler or Bent Exhaust Pipe

Oil
System Failure
Scored or Leaky Piston Rings

Popping-Spitting-Detonation
Improper Ignition
Improper Carburetion
Excessive Carbon
Deposit
in Combustion
Cham­
bers
Poor Valve Seating Sticking Valves
Broken Valve Spring Tappets Adjusted too Close

Spark
Plug Electrodes Burned
Water or Dirt in
Fuel
Clogged
Lines Improper Valve Timing
Excessive Oil Comsumption Piston Rings Stuck in Grooves, Worn or Broken Piston Rings Improperly Fitted or Weak Piston Ring Oil Return
Holes
Clogged
Excessive Clearance, Main and Connecting Rod
Bearings

Oil
Leaks at Gaskets or Oil Seals
Excessive Clearance, Valve Stem to Valve Guide (Intake)

Cylinder
Bores Scored, Out-of-Round or Tapered Too Much Clearance, Piston to Cylinder Bore
Misaligned Connecting Rods
High Road
Speeds
or Temperature
Crankcase
Ventilator Not Operating
Bearing Failure
Crankshaft
Bearing Journal Out-of-Round

Crankshaft
Bearing Journal Rough

Lack
of Oil
Oil
Leakage
Dirty
Oil

Low
Oil Pressure or Oil Pump Failure
Drilled
Passages
in Crankcase or Crankshaft
Clogged

Oil
Screen Dirty Connecting Rod Bent 70

'Jeep'
UNIVERSAL SERIES SERVICE
MANUAL

Dl

©©©©©©©©©

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

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

Dl Caution:
Oil ports of the rocker arm shaft must
coincide with oil return passages of the rocker

arms.
If they do not,
engine
oil has no return path

from
the cylinder head to the crankcase; in that
case,
engine
oil flows down the valve
stems
and

burns
in the cylinders.
There
is a notch at one end of each rocker arm shaft. When rocker arms
are
properly installed on the shaft, this notch
will

be at front of right rocker arm shaft and at
rear
of left rocker arm shaft. Refer to
Figs.
Dl-25 and

Dl-26.

a.
Position center support on rocker arm shaft;

insert
one shaft assembly attaching bolt through
support and shaft to hold support in position.

b.
Install
center
pair
of rocker arms with notched
faces touching support.
Install
front and
rear
spacer
FIG.
Dl-25—FRONT
OF RIGHT

ROCKER
ARM SHAFT
1—Alignment Notch

FIG.
Dl-26—REAR OF
LEFT
ROCKER
ARM SHAFT 2—Alignment Notch springs and one rocker arm each of front and
rear

rocker
arm pairs on shaft. Be certain that notched
faces of rocker arms are outward.
Install
outer shaft supports on shaft; compress spacer springs
to position supports. Insert one shaft assembly bolt
through each support and shaft to hold supports in
position.

c.
Install
remaining rocker arms of front and
rear

pairs,
each with notched face touching shaft sup­

port.
Install
a spring retaining ring and flat washer at each end of shaft; secure each of
these
with a
new cotter pin.

D1 -61.
Valve Removal

a.
Place cylinder head on clean, smooth surface.

b.
Remove each valve assembly from cylinder
head as follows. Using suitable spring compressor, compress valve spring and remove two valve re­

tainers
from valve stem. Release spring compressor,

and
remove spring retainer and valve spring from
valve stem. Refer to Fig. Dl-27.

Note:
Valve retainers are copper-colored for identi­
fication purposes only.

c.
Withdraw valve from
bottom
of cylinder head.
Valves
should be identified so they can be installed

in
original location.

D1-62.
Cylinder
Head and Valve Cleaning
and
Inspection

a.
Remove carbon from combustion chamber of
cylinder
heads, using care to avoid scratching the head of valve seat surfaces. A
soft
wire brush is
suitable for this purpose.

b.
Clean
carbon and gum
deposits
from valve guide
bores with a standard-size valve guide reamer.

Refer
to Fig. Dl-28.

c.
Clean
valves with a wire
brush.
Inspect valve
faces and
seats
for pits, burned
spots
or other evi­ dence of poor seating.
FIG.
D1 -2 7—REMOVING
VALVE
RETAINERS
1—
Valve
Stem 3—Valve Spring Retainer

2—
Valve
Lock
4—Valve Spring
93

Dl

DAUNTLESS
V-6
ENGINE

FIG.
D1-28—CLEANING
OR
ENLARGING
VALVE
GUIDE

1—Reamer
d.
Measure clearance of each valve stem in cor­
responding valve guide. For intake valves, this
clearance
should be .0012" to .0032" [0,0305 a

0,0813
mm.]. For exhaust valves, this clearance should be .0015" to .0035"
[0,0381
a
0,0889
mm.]
at top of guide and .002" to .004"
[0,051
a 0,102 mm.] at bottom of guide. If this clearance is exces­
sive, valve guides must be reamed with .004" [0,102 mm.] oversized reamer J-5830-1 and valves

replaced
by new valves with oversize stems.

Dl-63.
Cylinder
Head
and Valve
Repair
a.
If a valve stem has excessive clearance in its
guide, the guide must be reamed .004" [0,102 mm.]
oversize. Valves are available with oversize stems
to fit this valve guide diameter.

b.
Grind
valve faces or replace valves if necessary.

Valve
faces must be ground at an angle of 45 degrees. If a valve head must be ground to a
knife
edge
to obtain a true face, the valve should
be replaced.

c.
If necessary, grind valve seats at an angle of 45 degrees.
Grinding
a valve seat decreases valve
spring
pressure and increases the width of the seat.

The
nominal width of the valve seat is
[
1,59
mm.].
If a valve seat is wider than %" [1,98 mm.]
after grinding, it should be narrowed to specified

width
by the use of 20-degree and 70-degree stones.
Improper
operation of a hydraulic valve lifter may

result
if valve and seat are refinished to the extent
that the valve stem is raised more than .050" [1,27 mm.] above normal height. In this case, it
is necessary to grind off the end of the valve stetti or replace parts.

Note:
The normal height of the valve stem above
the valve spring seat surface of the head is
1.925"
[4,889 cm.].

d.
Lightly
lap the valves into seats with fine grind­
ing compound. The refacing and reseating should
leave the refinished surfaces smooth and true so that a minimum of lapping
will
be required. Ex­
cessive lapping
will
groove the valve face and pre­
vent
good
valve seating.
e. Test valve seats for concentricity with guides,
and
for proper valve seating. Coat a small segment
of the valve face lightly with Prussian blue pig­ ment.. Insert the valve stem into its guide and

turn
the valve face against the seat. If the valve seat is concentric with the valve guide, a
mark

will
be made all around the seat. If the seat is not concentric with the guide, a
mark
will
be made
on only one side of the seat.

Clean
all pigment from both valve and seat. .Next,
coat a small segment of the valve seat lightly with

Prussian
blue pigment. Again insert the valve stem into its guide and rotate the valve face against the
seat. If the valve face is concentric with the valve
stem, and if the valve is seating all the way around,
pigment
will
coat the valve face with a uniform
band
around its entire perimeter. Both of
these

tests
are necessary to prove that proper valve seat­
ing is obtained.
f. Inspect the valve springs visually for corrosion,

breaks,
and distortion.
With
a valve spring tester
check
each valve spring for proper tension. When

a
valve spring is compressed to a length of
1.640"
[4,166 cm.] (closed-valve condition), it should
have a tension of 64 lb. [29,03 kg.]. When a valve
spring
is compressed to a length of
1.260"
[3,200
cm.] (open-valve condition), it should have ten­ sion of 168 lb. [76,205 kg.]. Replace any valve
spring
which is visibly damaged or
does
not
meet

tension specifications.

Dl-64.
Valve Installation

Lubricate
valve stems with engine oil.
Install
valves, valve springs, spring retainers, and valve

retainers
on the cylinder head. Use the same equipment and reverse procedure used for removal.

Install
valve springs with closely wound coils to­

ward
the cylinder head. Refer to Fig. Dl-29.
FIG.
Dl-29—VALVE
SPRING

1—
Spring

2—
Close
Wound
Coils
Toward
Head
94

Dl

DAUNTLESS
V-6
ENGINE
Note:
During
engine
reassembly, use Perfect Seal

Aerosol
Spray Sealer
Part
No.
994757
on all en­
gine
gaskets to ensure against vacuum, oil, gasoline

and
water leaks. Apply to head gaskets, valve covers, water pumps, oil pan gaskets, radiator and
heater
hose
connections, felt gaskets, gasoline and
oil
line connections, stud bolts, spark plug threads,

and
grease retainer washers. Refer to manufac­
turer's
instructions on container for proper appli­
cation procedure.

Dl-72.
Cylinder
Block
and Crankshaft
Rear
Oil Seals

Braided
fabric seals are pressed into
grooves
of
cylinder
block and
rear
main bearing cap, to
rear

of the oil collecting groove, to seal against oil leak­ age at the crankshaft. Refer to Fig. Dl-32.

FIG.
Dl-32—INSTALLING
CRANKSHAFT REAR
OIL
SEAL

1—Neoprene
Seal
2—Fabric
Seal

A
neoprene composition (stick) seal is installed in
grooves
in the sides of the
rear
main bearing cap
to seal against leakage in the joints
between
the
cap and cylinder block. The neoprene composition
expands in the presence of oil and heat.
This
seal
is undersize when newly installed. Refer to Fig.

Dl-32.

a.
The braided fabric seal can be installed in the

cylinder
block only when the crankshaft is re­ moved; however, the seal in the cap can be replaced
whenever the cap is removed. Remove oil seal and place new seal in groove, with both ends projecting
above parting surface of cap. Force seal into
groove

by rubbing down with hammer handle or smooth
stick
until seal projects above the
groove
not more

than
[1,59 mm.]. Cut ends off flush with
sur­

face of cap, using sharp knife or razor blade.
Lubricate
the seal with heavy
engine
oil just before
installation.

Caution:
The
engine
must be operated at slow
speed when first started after new braided seal
has been installed.
b. The neoprene composition seal is slightly longer

than
the
grooves
in the bearing cap. The seal must
not be cut to length. The seals are installed after the bearing cap is installed in the block and torqued
firmly
in place. Dip the neoprene seals in kerosene
approximately IV2 minutes, then install seals into
bearing cap grooves. The protruding ends of the seals are, again, squirted with kerosene, wiped off,

and
peaned over with a hammer to be sure of a
seal
at the upper parting line
between
the cap and

cylinder
block.

Dl-73.
Main
Bearing and Crankshaft
Installation

Refer
to Fig. Dl-6.

This
procedure assumes that crankshaft main bear­
ings have been inspected and proven satisfactory,

or
that new crankshaft main bearings of appropriate size have been selected. If necessary, check or select
main
bearings as described in Par. Dl-41 and
Pars.

Dl-42 and Dl-43.

a.
Install
four upper main bearing halves in
seats

of cylinder block so that prong of each bearing half
fits into corresponding notch of seat. Flanged thrust
bearing must be installed in the second seat from
front of engine.
Install
a new upper crankshaft
rear
oil seal in the cylinder block as described in

Par.
Dl-72.

Caution:
Upper main bearing halves have an oil groove, while lower halves are plain. They must
not be interchanged.
b. Apply
engine
oil to upper bearing surfaces.

Install
the crankshaft so that its four journals rest

in
the upper bearing halves.
c. Seat all four lower main bearing halves in cor­
responding bearing caps.
Install
a new lower
crank­

shaft
rear
oil seal and cylinder block
rear
oil seal
described in
Par.
Dl-72, a and b.
Lubricate
all lower

main
bearing surfaces with
engine
oil. Position bear­ ing caps to cylinder block and crankcase journals.

Install
two cap bolts,
loosely,
at each cap.

d.
It is necessary to align thrust surfaces of the
second main bearing whenever it has been removed

from
the engine. To do this, pry the crankshaft

back
and forth several times, throughout its entire end travel, with cap
bolts
of second main bearing
only finger tight.
e. Tighten alternate cap
bolts
of each main bearing

cap,
a little at a time, until they have been tight­ ened to 80 to 110 lb-ft. [11,1 a 15,2 kg-m.] torque.
D1-74. Crankshaft End Play Check

To
measure crankshaft end play, mount a dial
indicator
on the cylinder block and index its plung­

er
to either a front or
rear
face of one crankshaft
counterweight. Pry the crankshaft to one limit
of its end travel and adjust the dial indicator to
zero. Pry the crankshaft to its
opposite
end travel

limit
and
note
end play as indicated by the dial

indicator.
Crankshaft end play tolerances are .004"
to .008" [0,102 a
0,204
mm.]. If end play is too great, it can be corrected only by replacement of
the second main (thrust) bearing.

Dl-75.
Piston and Connecting Rod
Installation

This
procedure assumes that connecting rod bear­ ings have been inspected and proven satisfactory,

or
that new connecting rod bearings of appropriate 96