1998 DODGE RAM 1500 Engine

CLEANINGÐPUSHRODS
Clean the pushrods in a suitable solvent. Rinse in
hot water and blow dry with compressed air. If nec-
essary, use a wire brush or wheel to remove stubborn
deposits.
INSPECTION
INSPECTION - CYLINDER HEAD
Inspect the cylinder head for cracks in the combus-
tion surface. Pressure test any cylinder head that is
visibly cracked. A cylinder head that is cracked
between the injector bore and valve seat can be pres-
sure tested and reused if OK; however, if the crack
extendsintothe valve seat insert bore, the cylinder
headmustbe replaced.
Visually inspect the cylinder block and head com-
bustion surfaces for localized dips or imperfections.
Check the cylinder head and block combustion sur-
faces for overall out-of-flatness. If either the visual or
manual inspection exceeds the limits, then the head
or block must be surfaced.
Check the top surface for damage caused by the
cylinder head gasket leaking between cylinders.
Inspect the block and head surface for nicks, ero-
sion, etc.
Check the head distortion. Maximum overall vari-
ation end to end is 0.305 mm (0.012 inch) (Fig. 13),
and maximum overall variation side to side 0.076
mm ( .003 in.).
DO NOT proceed with the in-chassis overhaul if
the cylinder head or block surface is damaged or not
flat (within specifications).
Check block surface for distortion. Maximum vari-
ation end-to-end is 0.076 mm ( .003 in.), side-to-side
0.051 mm (.002).Visually inspect the cylinder head bolts for dam-
aged threads, corroded/pitted surfaces, or a reduced
diameter due to bolt stretching.
If the bolts are not damaged, their ªfree lengthº
should be measured using the cap screw stretch
gauge provided with the replacement head gasket.
Place the head of the bolt against the base of the slot
and align the bolt with the straight edge of gauge
(Fig. 14). If the end of the bolt touches the foot of the
gauge, the boltmustbe discarded.The maximum
bolt free length is 132.1 mm (5.200 in.).
INSPECTIONÐCROSSHEADS
Inspect the crossheads for cracks and/or excessive
wear on rocker lever and valve tip mating surfaces
(Fig. 15). Replace any crossheads that exhibit abnor-
mal wear or cracks.
Fig. 13 Cylinder Head Combustion Deck Face
1 - STRAIGHT EDGE
2 - FEELER GAUGE
Fig. 14 Head Bolt Stretch Gauge
Fig. 15 Inspecting Crosshead for Cracks
9 - 252 ENGINE 5.9L DIESELDR
CYLINDER HEAD (Continued)

INSPECTIONÐPUSHRODS
Inspect the push rod ball and socket for signs of
scoring. Check for cracks where the ball and the
socket are pressed into the tube (Fig. 16).
Roll the push rod on a flat work surface with the
socket end hanging off the edge (Fig. 17). Replace
any push rod that appears to be bent.
INSTALLATION
WARNING: THE OUTSIDE EDGE OF THE HEAD
GASKET IS VERY SHARP. WHEN HANDLING THE
NEW HEAD GASKET, USE CARE NOT TO INJURE
YOURSELF.
(1) Install a new gasket with the part number side
up, and locate the gasket over the dowel sleeves.
(2) Using an engine lifting crane, lower the cylin-
der head onto the engine.
(3) Lightly lubricate head bolts with engine oil and
install. Using the sequence shown in (Fig. 18),
tighten bolts in the following steps:
(a) Torque bolts to 70 N´m (52 ft. lbs.)(b) Back off 360 degrees in sequence
(c) Torque bolts to 105 N´m (77 ft. lbs.)
(d) Re-check all bolts to 105 N´m (77 ft. lbs.)
(e) Tighten all bolts an additional
1¤4turn (90É)
(4) Install push rods into their original locations
(Fig. 19).Verify that they are seated in the tap-
pets.
(5) Lubricate valve stem tips and install the cross-
heads in their original locations.
(6) Lubricate the rocker arms and pedestals and
install them in their original locations (Fig. 20).
Install the bolts and torque them to 36 N´m (27 ft.
lbs.).
(7) Verify that the valve lash settings are main-
tained (Refer to 9 - ENGINE/CYLINDER HEAD/IN-
TAKE/EXHAUST VALVES & SEATS - STANDARD
PROCEDURE).
(8) Inspect rocker housing gasket for cuts and
proper installation into groove. Replace if damaged.
Fig. 16 Inspecting Push Rod for Cracks
Fig. 17 Inspecting Push Rod for Flatness
Fig. 18 Cylinder Head Bolt Torque Sequence
Fig. 19 Push Rod Installation
DRENGINE 5.9L DIESEL 9 - 253
CYLINDER HEAD (Continued)

(9) Install rocker housing and bolts. Tighten to 24
Nm (18 lb. ft.).
(10) Install fuel injector(Refer to 14 - FUEL SYS-
TEM/FUEL INJECTION/FUEL INJECTOR -
INSTALLATION).
(11) Install injector harness nuts. Tighten to 1.25
Nm (11 lb. in.).
(12) Install cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(13) Install wire harness P-clip to cylinder head
behind filter housing 24 N´m (18 ft. lbs.).
(14) Connect the IAT/MAP sensor connector.
(15) Install the fuel filter canister assembly and
torque mounting bolts to 24 N´m (18 ft. lbs.).
(16) Connect fuel lift pump, WIF sensor, and fuel
heater.
(17) Remove the engine lift bracket at rear of cyl-
inder head.
CAUTION: Failure to follow procedure will result in
fuel leaks and/or fuel system failure.
(18)Install the fuel rail and high pressure
fuel lines as follows:
(a) Hand tighten fuel rail bolts.
(b) Hand tighten fuel drain line to pressure lim-
iting valve. Hand tighten banjo bolt at fuel filter
housing.
(c) Hand tighten fuel rail-to-cylinder head high
pressure fuel lines.(d) Install fuel line brace bolts-to-intake mani-
fold finger tight.
(e) Hand tighten fuel pump to fuel rail line.
(f) Torque fuel line nuts at cylinder head to 30
Nm ( 22 ft. lbs.).
(g) Torque fuel line nuts at fuel rail to 30 Nm
(22 ft. lbs.)
(h) Using a back up wrench, torque fuel pump to
fuel rail line to 37 Nm (27 ft. lbs.). At injection
pump.
(i) Torque fuel pump to fuel rail line to 37 Nm
(27 ft. lbs.) at fuel rail.
(j) Torque fuel drain banjo bolt at pressure lim-
iting valve and front of fuel filter housing to 24 Nm
(18 ft. lbs.).
(k) Torque fuel line brace bolts to 24 N´m (18 ft.
lbs.).
(l) Torque rail bolts to 24 Nm (18 ft. lbs.).
(m) Connect fuel pressure sensor.
(19) Install the engine lift bracket at the rear of
cylinder head. Torque to 77 N´m (57 ft. lbs.).
(20) Reposition number 6 fuel line shield and
torque to 43 N´m (32 ft. lbs.).
(21) Install the fuel filter to injection pump low
pressure line. Inspect and replace sealing washers if
necessary. Torque banjo bolts to 24 N´m (18 ft. lbs.).
(22) Connect fuel return line at back of cylinder
head hand tight.
(23) Connect fuel return line at filter housing hand
tight.
(24) Torque banjo connections at cylinder head and
fuel filter housing to 24 Nm (18 ft. lbs.)
(25) Install bracket to rear of filter housing.
Torque to 24 Nm (18 ft. lbs.).
(26) Using new gaskets, install the intake grid
heater and air inlet housing. Torque bolts to 24 N´m
(18 ft. lbs.).
(27) Install wire harness P-clip and push on clip to
air inlet housing.
(28) Connect engine oil level indicator tube at fuel
filter housing and at air inlet housing.
(29) Connect the APPS connector.
(30) Install the APPS assembly to the cylinder
head bracket and torque bolts to 24 N´m (18 ft. lbs.).
(31) Install the throttle linkage cover.
(32) Install the charge air cooler-to-air inlet hous-
ing duct assembly. Torque all clamps to 11 N´m (100
in. lbs.).
(33) Connect intake grid heater wires.
(34) Secure engine harness to front of cylinder
head with bolt at four locations.
(35) Connect engine coolant temperature sensor
connector.
(36) Connect radiator upper hose to thermostat
housing.
Fig. 20 Rocker Arm and Pedestal Removal
1 - ROCKER ARM
2 - PEDESTAL
9 - 254 ENGINE 5.9L DIESELDR
CYLINDER HEAD (Continued)

(37) Rotate generator into position. Install upper
bolt and torque upper and lower bolts.
(38)
Install wire harness push-on clip below bracket.
(39) Install wire harness P-clip to top of bracket.
(40) Install fan support and torque to 32 N´m (24
ft. lbs.).
(41) Install cooling fan/drive refer to (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - INSTALLA-
TION).
(42) Install accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(43) Install exhaust manifold/turbocharger assem-
bly, using new gaskets. Start all bolts/spacers by
hand. Torque bolts to 43 N´m (32 ft. lbs.).
(44) Install exhaust manifold heat shield to
exhaust manifold studs. Install retaining nuts.Torque
to 15 N´m (11 ft. lbs.).
(45) Install exhaust bolt retention straps across
cylinders5&6.
(46) Connect turbocharger oil drain tube. Torque
clamp to 8 N´m (71 in. lbs.).
(47) Perform the turbocharger pre-lube procedure.
Refer to Group 11, Exhaust System and Turbo-
charger for the correct procedure.
(48) Connect the turbocharger oil supply line.
Torque to 24 N´m (18 ft. lbs.).
(49) Install air cleaner housing and duct.
(50) Connect air inlet temperature/pressure sensor.
(51) Raise vehicle on hoist.
(52) Install exhaust pipe to turbocharger elbow.
Torque bolts to 11 N´m (100 in. lbs.).
(53) Lower vehicle.
(54) Fill engine coolant (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(55) Start engine and check for leaks.
CYLINDER HEAD COVER(S)
REMOVAL
REMOVALÐCYLINDER HEAD COVER
(1) Disconnect both battery negative cables.
(2) Remove oil fill cap.
(3) Remove the breather cover.
(4) Disconnect the breather hose and breather
drain tube from the breather housing.
(5) Remove cylinder head cover bolts.
(6) Remove the cylinder head cover.
REMOVALÐROCKER HOUSING
(1) Remove cylinder head cover as outlined in this
section.
(2) Disconnect rocker housing injector harness con-
nectors.(3) Remove injector harness nuts from injectors.
(4) Remove rocker housing bolts.
(5) Remove rocker housing and gasket.
CLEANING
Using a suitable solvent, Clean and dry gasket
mating surfaces on cylinder head and rocker housing.
Wipe gasket dry and inspect for re-use.
INSPECTION
The cylinder head cover gasket and rocker hous-
ing gasket, are reusable.However, should cracks,
nicks, or tears be present in the rubber/silicone construc-
tion, the defective components should be replaced. Also
replace gasket if it is no longer flexible. Inspect o-rings
on cylinder head cover bolts.Do not reuse gasket if it
has been removed from the groove in the rocker
housing or cylinder head cover.
INSTALLATION
INSTALLATIONÐCYLINDER HEAD COVER
(1) Inspect cylinder head cover gasket for cuts and
proper installation in groove. Replace if damaged.
(2)
Position cylinder cover on top of rocker housing.
(3) Install bolts.
(4) Starting with the center bolt, torque to 24 N´m
(18 ft. lbs.).
(5) Install breather hose to breather.
(6) Install breather drain hose to breather.
(7) Install breather cover and wire harness clip.
Torque to 24 N´m (18 ft. lbs.).
INSTALLATION - ROCKER HOUSING
(1) Inspect rocker housing gasket for cuts, nicks,
or tears. Replace if damaged or if gasket has come
out of groove.
(2) Inspect rocker housing gasket for proper instal-
lation in groove. Gasket bead must be centered in
groove. A gasket bead that is tilted to the side will
cause an oil leak.
CAUTION: When installing rocker housing onto cyl-
inder head, do not slide housing from side to side,
The gasket could fall out or be damaged.
(3) Install the rocker housing. Carefully guide the
rocker housing evenly down onto the cylinder head.
(4) Install rocker housing bolts and tighten finger
tight.
(5) Torque bolts, working from center out, to 24
Nm (18ft. lbs.).
(6) Install injector harness nuts to injector sole-
noid. Torque to 1.25 Nm (11 in. lbs.).
(7) Connect rocker housing injector harness con-
nections.
DRENGINE 5.9L DIESEL 9 - 255
CYLINDER HEAD (Continued)

INTAKE/EXHAUST VALVES &
SEATS
DESCRIPTION
The valves are made of heat resistant steel, and
have chrome plated stems to prevent scuffing. The
intake and exhaust valves are both similar in head
diameter and overall length, but they have unique
face angles which makes them non-interchangeable.
The valves are distinguished by unique dimples on
the exhaust valve head (Fig. 21).
The exhaust valve springs are made from high
strength, chrome silicon steel. The exhaust valve
springs are also exhaust brake compatible.
STANDARD PROCEDURE
STANDARD PROCEDURE - VALVES, GUIDES
AND SPRINGS
REMOVAL
(1) Remove cylinder head (Refer to 9 - ENGINE/
CYLINDER HEAD - REMOVAL).
(2) Support cylinder head on stands, or install
head bolts upside down (through combustion surface
side) to protect injector tips from damage from work
bench.
(3) Install the valve spring compressor mounting
base as shown in (Fig. 22).
(4) Install the compressor top plate, washer, and
nut. Using a suitable wrench, tighten the nut (clock-
wise) to compress the valve springs (Fig. 23) and
remove the locks.
Fig. 22 Spring Compressor Mounting BaseÐPart of
Tool 8319±A
1 - COMPRESSOR MOUNTING BASE
Fig. 23 Compressing Valve Springs with Tool
8319±A
1 - SPECIAL TOOL 8319
Fig. 21 Valve Identification
1 - INTAKE VALVES
2 - EXHAUST VALVES
9 - 256 ENGINE 5.9L DIESELDR

(5) Rotate the compressor nut counter-clockwise to
relieve tension on the springs. Remove the spring
compressor.
(6) Remove the retainers, springs, valve seals (if
necessary), and valves (Fig. 24). Arrange or number
all components so they can be installed in their orig-
inal locations.
(7) Repeat the procedure on all cylinders to be ser-
viced.
CLEANING
Clean the valve stems with crocus cloth or a
Scotch-BriteŸ pad. Remove carbon with a soft wire
brush. Clean valves, springs, retainers, and valve
retaining locks in a suitable solvent. Rinse in hot
water and blow dry with compressed air.
INSPECTION
Visually inspect the valves for abnormal wear on
the heads, stems, and tips. Replace any valve that is
worn out or bent (Fig. 25).
Measure the valve stem diameter in three places
as shown in (Fig. 26).
Measure the cylinder head valve guide bore (Fig.
27).
VALVE GUIDE BORE SPECIFICATIONS
VALVE GUIDE BORE SPECIFICATIONS
Valve guide bore
diameter
Min. 7.027 mm (0.2767 in.)
Max. 7.077 mm (0.2786 in.)
Installed valve guide
depth
Intake
Min. 0.584 mm ( 0.023 in.)
Max. 1.092 mm ( 0.043 in.)
Exhaust
Min. 0.965 mm ( 0.028 in.)
Max. 1.473 mm (0.058 in.)
Fig. 24 Valve Spring, Seal, and Retainers
1 - VALVE RETAINING LOCKS
2 - VALVE
3 - SEAL
4 - SPRING
5 - RETAINER
Fig. 25 Visually Inspect Valves for Abnormal Wear
Fig. 26 Measure Valve Stem Diameter
VALVE STEM DIAMETER
6.96 mm (0.2740 in.) MIN
7.010 mm (0.2760 in.) MAX
DRENGINE 5.9L DIESEL 9 - 257
INTAKE/EXHAUST VALVES & SEATS (Continued)

Measure valve margin (rim thickness) (Fig. 28).
Measure the valve spring free length and maxi-
mum inclination (Fig. 29).
Test valve spring force with tool C-647 (Fig. 30).
Specification 72.0 Ð 80.7 lbs. when compressed to
35.33 mm (1.39 in.).
Fig. 27 Measure Valve Guide Bore
Fig. 28 Measure Valve Margin (Rim Thickness)
VALVE MARGIN (RIM THICKNESS)
0.79 mm (0.031 in.) MIN.
Fig. 29 Measure Valve Spring Free Length and Max.
Inclination
APPROXIMATE VALVE SPRING FREE LENGTH
47.75 mm (1.88 in.)
MAX INCLINATION
1.5 mm (.059 in.)
Fig. 30 Testing Valve Spring with Tool C-647
1 - SPECIAL TOOL C-647
9 - 258 ENGINE 5.9L DIESELDR
INTAKE/EXHAUST VALVES & SEATS (Continued)

INSTALLATION
(1) Install new valve seals. The yellow seals are for
the intake valves and the green seals are for the
exhaust valves.
(2) Install the valves in their original postion. The
exhaust valves are identified by a dimple on the
valve head (Fig. 31).
(3) Install the valve springs and retainer.
(4) Install the valve spring compressor tool 8319±A
as shown in (Fig. 22) and (Fig. 23).
(5) Compress the valve springs and install the
valve retaining locks (Fig. 24).
(6) Remove the compressor and repeat the proce-
dure on the remaining cylinders.
(7) Install new o-ring and sealing washer on injec-
tor.
(8) Lubricate o-ring and injector bore.
(9) Verify sealing washer (shim) was removed with
old injector.
(10) Install injector Refer to (Refer to 14 - FUEL
SYSTEM/FUEL INJECTION/FUEL INJECTOR -
INSTALLATION).
(11) Install the cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - INSTALLATION).
STANDARD PROCEDURE - VALVE LASH
ADJUSTMENT AND VERIFICATION
NOTE: To obtain accurate readings, valve lash mea-
surements AND adjustments should only be per-
formed when the engine coolant temperature is less
than 60É C (140É F).
The 24±valve overhead system is a ªlow-mainte-
nanceº design. Routine adjustments are no longer
necessary, however, measurement should still takeplace when trouble-shooting performance problems,
or upon completion of a repair that includes removal
and installation of the valve train components or
injectors.
(1) Disconnect battery negative cables.
(2) Remove cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(3) Using the crankshaft barring tool #7471±B,
rotate crankshaft to align damper TDC mark to
12:00 o'clock position.
(a) If both number one cylinder rocker levers are
loose, continue to next step.
(b) If both number one clylinder rocker levers
are not loose, rotate crankshaft 360 degrees.
(4) With the engine in this position, valve lash can
be measured at the following rocker arms:INTAKE
1±2±4 / EXHAUST 1±3±5. Measure the valve lash by
inserting a feeler gauge between the rocker arm
socket and crosshead (Fig. 32). Refer to VALVE
LASH LIMIT CHART for the correct specifications. If
the measurement fallswithinthe limits, adjust-
ment/resettingis notnecessary. If measurement
finds the lashoutsideof the limits, adjustment/re-
settingisrequired.
VALVE LASH LIMIT CHART
INTAKE EXHAUST
0.152 mm ( 0.006 in.)
MIN.0.381 mm (0.015 in.)
MIN.
0.381 mm (0.015 in.)
MAX.0.762 mm (0.030 in.)
MAX.
note:
If measured valve lash falls within these
specifications, no adjustment/reset is necessary.
Engine operation within these ranges has no adverse
affect on performance, emissions, fuel economy or
level of engine noise.
(5) If adjustment/resetting is required, loosen the
lock nut on rocker arms and turn the adjusting screw
until the desired lash is obtained:
²INTAKE0.254 mm (0.010 in.)
²EXHAUST0.508 mm (0.020 in.) Tighten the
lock nut to 24 Nm (18 ft. lbs.) and re-check the valve
lash.
(6) Using the crankshaft barring tool, rotate the
crankshaftone revolution (360É) to align the
damper TDC mark to the 12 o'clock position.
Fig. 31 Valve Identification
1 - INTAKE VALVES
2 - EXHAUST VALVES
DRENGINE 5.9L DIESEL 9 - 259
INTAKE/EXHAUST VALVES & SEATS (Continued)