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Dodge Durango (DN). Manual - part 456

Use a 2 step procedure so the valve guides are
reamed true in relation to the valve seat:

• Step 1—Ream to 0.0763 mm (0.003 inch).

• Step 2—Ream to 0.381 mm (0.015 inch).

REFACING VALVES AND VALVE SEATS

The intake and exhaust valves have a 43-1/4° to

43-3/4° face angle and a 44-1/4° to 44-3/4° seat angle
(Fig. 20).

VALVES
Inspect the remaining margin after the valves are

refaced (Fig. 21). Valves with less than 1.190 mm
(0.047 inch) margin should be discarded.

VALVE SEATS

CAUTION: DO NOT un-shroud valves during valve
seat refacing (Fig. 22).

(1) When refacing valve seats, it is important that

the correct size valve guide pilot be used for reseat-
ing stones. A true and complete surface must be
obtained.

(2) Measure the concentricity of valve seat using a

dial indicator. Total runout should not exceed 0.051
mm (0.002 inch) total indicator reading.

(3) Inspect the valve seat with Prussian blue to

determine where the valve contacts the seat. To do
this, coat valve seat LIGHTLY with Prussian blue
then set valve in place. Rotate the valve with light
pressure. If the blue is transferred to the center of
valve face, contact is satisfactory. If the blue is trans-
ferred to the top edge of valve face, lower valve seat
with a 15° stone. If the blue is transferred to bottom
edge of valve face raise valve seat with a 60° stone.

(4) When seat is properly positioned the width of

intake seats should be 1.016-1.524 mm (0.040-0.060

REAMER SIZES

REAMER O/S

VALVE GUIDE SIZE

0.076 mm (0.003 in.)

8.026 - 8.052 mm

(0.316 - 0.317 in.)

0.381 mm (0.015 in.)

8.331 - 8.357 mm

(0.328 - 0.329 in.)

Fig. 20 Valve Face and Seat Angles

1 – CONTACT POINT

VALVE FACE AND VALVE SEAT ANGLE CHART

ITEM

DESCRIPTION

SPECIFICATION

SEAT WIDTH–

1.016 - 1.524 mm

INTAKE

(0.040 - 0.060 in.)

SEAT WIDTH–

1.524 - 2.032 mm

EXHAUST

(0.060 - 0.080 in.)

FACE ANGLE

(INT. and EXT.)

⁄

° - 43

⁄

SEAT ANGLE

(INT. and EXT.)

⁄

° - 44

⁄

CONTACT

SURFACE

—

Fig. 21 Intake and Exhaust Valves

1 – MARGIN
2 – VALVE SPRING RETAINER LOCK GROOVE
3 – STEM
4 – FACE

9 - 154

5.9L ENGINE

SERVICE PROCEDURES (Continued)

inch). The width of the exhaust seats should be
1.524-2.032 mm (0.060-0.080 inch).

VALVE SPRING INSPECTION

Whenever valves have been removed for inspection,

reconditioning or replacement, valve springs should
be tested. As an example the compression length of
the spring to be tested is 1-5/16 inch. Turn table of
Universal Valve Spring Tester Tool until surface is in
line with the 1-5/16 inch mark on the threaded stud.
Be sure the zero mark is to the front (Fig. 23). Place
spring over stud on the table and lift compressing
lever to set tone device. Pull on torque wrench until
ping is heard. Take reading on torque wrench at this
instant. Multiply this reading by 2. This will give the
spring load at test length. Fractional measurements
are indicated on the table for finer adjustments.
Refer to specifications to obtain specified height and
allowable tensions. Discard the springs that do not
meet specifications.

MEASURING TIMING CHAIN STRETCH

NOTE: To access timing chain Refer to Timing
Chain Cover in Removal and Installation Section.

(1) Place a scale next to the timing chain so that

any movement of the chain may be measured.

(2) Place a torque wrench and socket over cam-

shaft sprocket attaching bolt. Apply torque in the
direction of crankshaft rotation to take up slack; 41
N·m (30 ft. lbs.) torque with cylinder head installed
or 20 N·m (15 ft. lbs.) torque with cylinder head
removed. With a torque applied to the camshaft

sprocket bolt, crankshaft should not be permitted to
move. It may be necessary to block the crankshaft to
prevent rotation.

(3) Hold a scale with dimensional reading even

with the edge of a chain link. With cylinder heads
installed, apply 14 N·m (30 ft. lbs.) torque in the
reverse direction. With the cylinder heads removed,
apply 20 N·m (15 ft. lbs.) torque in the reverse direc-
tion. Note the amount of chain movement (Fig. 24).

(4) Install a new timing chain, if its movement

exceeds 3.175 mm (1/8 inch).

(5) If chain is not satisfactory, remove camshaft

sprocket attaching bolt and remove timing chain with
crankshaft and camshaft sprockets.

(6) Place both camshaft sprocket and crankshaft

sprocket on the bench with timing marks on exact
imaginary center line through both camshaft and
crankshaft bores.

Fig. 22 Refacing Valve Seats

1 – STONE
2 – PILOT
3 – VALVE SEAT
4 – SHROUD

Fig. 23 Testing Valve Spring for Compressed

Length

1 – TORQUE WRENCH
2 – VALVE SPRING TESTER

Fig. 24 Measuring Timing Chain Wear and Stretch

1 – TORQUE WRENCH
2 – 3.175 MM

(0.125 IN.)

5.9L ENGINE

9 - 155

SERVICE PROCEDURES (Continued)

(7) Place timing chain around both sprockets.
(8) Turn crankshaft and camshaft to line up with

keyway location in crankshaft sprocket and in cam-
shaft sprocket.

(9) Lift sprockets and chain (keep sprockets tight

against the chain in position as described).

(10) Slide both sprockets evenly over their respec-

tive shafts and use a straightedge to check alignment
of timing marks (Fig. 25).

(11) Install the camshaft bolt. Tighten the bolt to

47 N·m (35 ft. lbs.) torque.

(12) Check camshaft end play. The end play should

be 0.051-0.152 mm (0.002-0.006 inch) with a new
thrust plate and up to 0.254 mm (0.010 inch) with a
used thrust plate. If not within these limits install a
new thrust plate.

PISTONS—FITTING

Piston and cylinder wall must be clean and dry.

Specified clearance between the piston and the cylin-
der wall is 0.013-0.038 mm (0.0005-0.0015 inch) at
21°C (70°F).

Piston diameter should be measured at the top of

skirt, 90° to piston pin axis. Cylinder bores should be
measured halfway down the cylinder bore and trans-
verse to the engine crankshaft center line.

Pistons and cylinder bores should be measured at

normal room temperature, 21°C (70°F).

Check the pistons for taper and elliptical shape

before they are fitted into the cylinder bore (Fig. 26).

PISTON RINGS—FITTING

(1) Measurement of end gaps:

(a) Measure piston ring gap 2 inches from bot-

tom of cylinder bore. An inverted piston can be
used to push the rings down to ensure positioning
rings squarely in the cylinder bore before measur-
ing.

(b) Insert feeler gauge in the gap. The top com-

pression ring gap should be between 0.254-0.508
mm (0.010-0.020 inch). The second compression

ring gap should be between 0.508-0.762 mm (0.020-
0.030 inch). The oil ring gap should be 0.254-1.270
mm (0.010-0.050 inch).

erly filed to the correct dimension. Rings with
excess gaps should not be used.
(2) Install rings and confirm ring side clearance:

(a) Install oil rings being careful not to nick or

scratch the piston. Install the oil control rings
according to instructions in the package. It is not
necessary to use a tool to install the upper and
lower rails. Insert oil rail spacer first, then side
rails.

(b) Install the second compression rings using

Installation Tool C-4184. The compression rings
must be installed with the identification mark face
up (toward top of piston) and chamfer facing down.
An identification mark on the ring is a drill point,
a stamped letter “O”, an oval depression or the
word TOP (Fig. 27) (Fig. 29).

pression ring with the chamfer facing up (Fig. 28)
(Fig. 29). An identification mark on the ring is a
drill point, a stamped letter “O”, an oval depression
or the word TOP facing up.

(d) Measure side clearance between piston ring

and ring land. Clearance should be 0.074-0.097 mm
(0.0029-0.0038 inch) for the compression rings. The
steel rail oil ring should be free in groove, but
should not exceed 0.246 mm (0.0097 inch) side
clearance.

(e) Pistons with insufficient or excessive side

clearance should be replaced.

Fig. 25 Alignment of Timing Marks

1 – TIMING MARKS

Fig. 26 Piston Measurements

1 – 49.53 mm

(1.95 IN.)

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5.9L ENGINE

SERVICE PROCEDURES (Continued)

CONNECTING ROD BEARINGS—FITTING

Fit all rods on a bank until completed. DO NOT

alternate from one bank to another, because connect-
ing rods and pistons are not interchangeable from
one bank to another.

The bearing caps are not interchangeable and

should be marked at removal to ensure correct
assembly.

Each bearing cap has a small V-groove across the

parting face. When installing the lower bearing shell,
make certain that the V-groove in the shell is in line
with the V-groove in the cap. This provides lubrica-
tion of the cylinder wall in the opposite bank.

The bearing shells must be installed so that the

tangs are in the machined grooves in the rods and
caps.

Limits of taper or out-of-round on any crankshaft

journals should be held to 0.025 mm (0.001 inch).
Bearings are available in 0.025 mm (0.001 inch),
0.051 mm (0.002 inch), 0.076 mm (0.003 inch), 0.254
mm (0.010 inch) and 0.305 mm (0.012 inch) under-
size. Install the bearings in pairs. DO NOT use a
new bearing half with an old bearing half. DO
NOT file the rods or bearing caps.

CRANKSHAFT MAIN BEARINGS—FITTING

Bearing caps are not interchangeable and should

be marked at removal to ensure correct assembly.
Upper and lower bearing halves are NOT inter-
changeable. Lower main bearing halves of No.2 and 4
are interchangeable.

PISTON MEASUREMENT CHART

PISTON

A DIA = PISTON

BORE

SIZE

DIAMETER

MIN.

MAX.

MIN.

MAX.

(in.)

mm (in.)

—

101.580

101.592

101.605

101.618

(3.9992)

(3.9997)

(4.0002)

(4.0007)

101.592

101.605

101.618

101.630

(3.9997)

(4.0002)

(4.0007)

(4.0012)

101.605

101.618

101.630

101.643

(4.0002)

(4.0007)

(4.0012)

(4.0017)

—

DESCRIPTION

SPECIFICATION

PISTON PIN BORE

25.007 - 25.015 mm

(.9845 -.9848 in.)

RING GROOVE

HEIGHT

OIL RAIL

4.033 - 4.058 mm

(.1588 -.1598 in.)

COMPRESSION

RAIL

1.529 - 1.554 mm

(.0602 -.0612 in.)

TOTAL FINISHED

470.8

2 grams

WEIGHT

(16.607

.0706 ounces)

Fig. 27 Second Compression Ring Identification

(Typical)

1 – SECOND COMPRESSION RING (BLACK CAST IRON)
2 – CHAMFER
3 – TWO DOTS

Fig. 28 Top Compression Ring Identification

(Typical)

1 – TOP COMPRESSION RING (GRAY IN COLOR)
2 – CHAMFER
3 – ONE DOT

5.9L ENGINE

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SERVICE PROCEDURES (Continued)

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