1998 DODGE RAM 1500 air

(15) Remove the two charge air cooler mounting
bolts.
(16) Remove charge air cooler (and A/C condenser
if equipped) from vehicle.
(17) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(18) Remove accessory drive belt tensioner.
(19) Remove the fan support/hub assembly.
(20) Remove crankshaft damper and speed indica-
tor ring (Refer to 9 - ENGINE/ENGINE BLOCK/VI-
BRATION DAMPER - REMOVAL).
(21) Remove the gear cover-to-housing bolts and
gently pry the cover away from the housing, taking
care not to mar the sealing surfaces. Remove dust
seal with cover.
(22) Using Special Tool 7471±B Crankshaft Bar-
ring Tool, rotate the crankshaft to align the timing
marks on the crankshaft and the camshaft gears.
(23) Remove the cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(24) Remove the rocker arms, cross heads, and
push rods (Fig. 55). Mark each component so they
can be installed in their original positions.
NOTE: The #5 cylinder intake and the #6 cylinder
intake and exhaust pushrods are removed by lifting
them up and through the provided cowl panel
access holes. Remove the rubber plugs to expose
these relief holes.
(25) Raise the tappets as follows, using the wooden
dowel rods (Fig. 57)provided with the Miller Tool Kit
8502.
(a) Insert the slotted end of the dowel rod into
the tappet.The dowel rods for the rear two
cylinders will have to be cut for cowl panel
clearance.Press firmly to ensure that it is seated
in the tappet.(b) Raise the dowel rod to bring the tappet to
the top of its travel, and wrap a rubber band
around the dowel rods (Fig. 57) to prevent the tap-
pets from dropping into the crankcase.
(c) Repeat this procedure for the remaining cyl-
inders.
(26) Verify that the camshaft timing marks are
aligned with the crankshaft mark (Fig. 56).
(27) Remove the bolts from the thrust plate.
(28) Remove engine mount through bolts.
(29) Install engine support fixture special tool #
8534,and steel bracket/wing nut special tool #
8534A.
(30) Raise engine enough to allow camshaft
removal.
(31) Remove the camshaft, gear and thrust plate.
Fig. 55 Push Rod Removal/Installation
Fig. 56 Timing Mark Alignment
Fig. 57 Use Wooden Dowel Rods to Secure Tappets
in Place - Typical
DRENGINE 5.9L DIESEL 9 - 269
CAMSHAFT & BEARINGS (IN BLOCK) (Continued)

(6) Remove the wooden dowel rods and rubber
bands from the tappets.
(7) Lubricate the push rods with engine oil and
install in their original location.Verify that they
are seated in the tappets.
(8) Lubricate the valve tips with engine oil and
install the crossheads in their original locations.
(9) Lubricate the crossheads and push rod sockets
with engine oil and install the rocker arms and ped-
estals in their original locations. Tighten bolts to 36
N´m (27 ft. lbs.) torque.
(10)Verify valve lash adjustment (Refer to 9 -
ENGINE/CYLINDER HEAD/INTAKE/EXHAUST
VALVES & SEATS - STANDARD PROCEDURE).
(11) Install the cylinder head cover and reusable
gasket (Refer to 9 - ENGINE/CYLINDER HEAD/
CYLINDER HEAD COVER(S) - INSTALLATION).
(12) Install gear housing cover (Refer to 9 -
ENGINE/VALVE TIMING/GEAR HOUSING COVER
- INSTALLATION). Install front crankshaft dust
seal.
(13) Install the crankshaft damper with the speed
indicator ring (Refer to 9 - ENGINE/ENGINE
BLOCK/VIBRATION DAMPER - INSTALLATION).
(14) Install the fan support/hub assembly Refer to
(Refer to 7 - COOLING/ENGINE/RADIATOR FAN -
INSTALLATION).
(15) Install the power steering pump.
(16) Install accessory drive belt tensioner. Torque
bolt to 43 Nm (32 ft. lbs.).
(17) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(18) Install the charge air cooler (with a/c con-
denser and auxiliary transmission oil cooler, if
equipped) and tighten the mounting bolts to 2 N´m
(17 in. lbs.) torque.
(19) Connect charge air cooler inlet and outlet
pipes. Tighten clamps to 11 N´m (95 in. lbs.) torque.
(20) Install the radiator upper support panel.
(21) Close radiator petcock and lower the radiator
into the engine compartment. Tighten the mounting
bolts to 11 N´m (95 in. lbs.) torque.
(22) Raise vehicle on hoist.
(23) Connect radiator lower hose and install
clamp.
(24) Connect transmission auxiliary oil cooler lines
(if equipped).
(25) Lower vehicle.
(26) Install the fan shroud and tighten the mount-
ing screws to 6 N´m (50 in. lbs.) torque.
(27) Install the electronically controlled viscous
fan/drive assembly. Connect harness connector.(Refer
to 7 - COOLING/ENGINE/RADIATOR FAN -
INSTALLATION).(28) Install the coolant recovery and windshield
washer fluid reservoirs to the fan shroud.
(29) Connect the coolant recovery hose to the radi-
ator filler neck.
(30) Add engine coolant (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(31) Charge A/C system with refrigerant (if A/C
equipped) (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING - STANDARD PROCEDURE).
(32) Connect the battery negative cables.
(33) Start engine and check for engine oil and cool-
ant leaks.
CONNECTING ROD BEARINGS
STANDARD PROCEDURE - CONNECTING ROD
BEARING AND CRANKSHAFT JOURNAL
CLEARANCE
(1) Measure the connecting rod bore with bearings
removedand the bolts tightened to 100 N´m (73 ft.
lbs.) torque..
(2) Measure the connecting rod bore with the bear-
ingsinstalledand the bolts tightened to 100 N´m
(73 ft. lbs.) torque.
Measure within 20É arc from each side of the part-
ing line. Also measure 90É from parting line.
Record the smallest and largest diameter.
Measure the diameter of the rod journal at the
location shown (Fig. 63). Calculate the average diam-
eter for each side of the journal.
Determine minimum bearing clearance by calculat-
ing the differance between the smallest connecting
rod bore diameter with the bearing installed and the
average diameter for each side of the crankshaft jour-
nal.
Determine the maximum bearing clearance by cal-
culating the difference between the largest connect-
ing rod bore diameter and the average diameter with
the bearing installed for each side of the crankshaft
journal.
DESCRIPTION MEASUREMENT
CONNECTING ROD
BORE, BEARINGS
REMOVEDMIN. 72.99 mm (2.874
in.)
MAX. 73.01 mm (2.875
in.)
CONNECTING ROD
BORE, BEARINGS
INSTALLEDMIN. 69.05 mm (2.719
in.)
MAX. 69.10 mm (2.720
in.)
9 - 272 ENGINE 5.9L DIESELDR
CAMSHAFT & BEARINGS (IN BLOCK) (Continued)

(6) Apply a bead of MopartSilicone Rubber Adhe-
sive Sealant or equivalent to the gear housing cover
sealing surface.
(7) Install the cover to the gear housing, aligning
the seal pilot with the nose of the crankshaft (Fig.
70).
(8) Install the cover bolts and tighten to 24 N´m
(18 ft. lbs.) torque. Remove pilot tool.
(9) Install dust shield over nose of crankshaft.
(10) Install the crankshaft damper and speed indi-
cator ring. Torque the bolts to 40 N´m (30 ft. lbs.).
Then rotate an additional 60É. Use the engine bar-
ring tool to keep the engine from rotating during
tightening operation.
(11) Install the fan support/hub assembly and
torque bolts to 32 N´m (24 ft. lbs.).
(12) Install power steering pump.
(13) Install accessory drive belt tensioner. Torque
bolt to 43 Nm (32 ft.lbs.).
(14) Install cooling fan (Refer to 7 - COOLING/EN-
GINE/RADIATOR FAN - INSTALLATION).
(15) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(16) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(17) Connect battery negative cables.
(18) Start engine and check for oil leaks.
CRANKSHAFT OIL SEAL -
REAR
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove the transmission and transfer case (if
equipped).(3) Remove the clutch cover and disc (if manual
transmission equipped) (Refer to 6 - CLUTCH/
CLUTCH DISC - REMOVAL).
(4) Remove the flywheel or converter drive plate.
(5) Drill holes 180É apart into the seal. Be careful
not to contact the drill against the crankshaft.
(6) Install #10 sheet metal screws in the drilled
holes and remove the rear seal with a slide hammer
(Fig. 71).
INSTALLATION
CAUTION: The seal lip and the sealing surface on
the crankshaft must be free from all oil residue to
prevent seal leaks. The crankshaft and seal sur-
faces must be completely dry when the seal is
installed. Use a soap and water solution on outside
diameter of seal to ease assembly.
(1) Clean the crankshaft journal with a suitable
solvent and dry with a clean shop towel or com-
pressed air. Wipe the inside bore of the crankshaft
seal retainer with a clean shop towel.
(2) Inspect the crankshaft journal for gouges,
nicks, or other imperfections. If the seal groove in the
crankshaft is excessively deep, install the new seal
1/8º deeper into the retainer bore, or obtain a crank-
shaft wear sleeve that is available in the aftermar-
ket.
(3) Install the seal pilot and new seal, provided in
the replacement kit, onto the crankshaft.
(4) Remove the seal pilot.
(5) Install the installation tool over crankshaft.
(6) Using a ball peen hammer, strike the tool at
the 12, 3, 6, and 9 o'clock positions until the align-
ment tool bottoms out on the retainer (Fig. 72).
Fig. 70 Installing Front Cover with Seal Pilot
1 - SEAL PILOT
Fig. 71 Crankshaft Rear Seal Removal
1 - NO. 10 SCREW
2 - REAR SEAL
3 - CRANKSHAFT
4 - SLIDE HAMMER
9 - 276 ENGINE 5.9L DIESELDR
CRANKSHAFT OIL SEAL - FRONT (Continued)

SOLID LIFTERS/TAPPETS
REMOVAL
NOTE: This procedure requires use of Miller Tool
8502 Tappet Replacement Kit.
(1) Remove camshaft (Refer to 9 - ENGINE/EN-
GINE BLOCK/CAMSHAFT & BEARINGS (IN
BLOCK) - REMOVAL).
(2) Insert the trough (provided with tool kit) the
full length of the camshaft bore (Fig. 77). Make sure
the cap end goes in first and the open side faces up
(towards tappets).
(3)Remove only one tappet at a time.Remove
rubber band from one cylinder pair and attach tappet
dowel not being removed to the next cylinder pair
(Fig. 78).
(4) Raise dowel rod (disengage from tappet) and
allow tappet to fall into trough (Fig. 79).
(5) Carefully remove trough(do not rotate)and
tappet. If the tappet is not being replaced, mark it so
it can be installed in its original location.
(6) Re-install trough and repeat procedure on
remaining tappets.
CLEANING
Clean tappet with a suitable solvent. Rinse in hot
water and blow dry with a clean shop rag or com-
pressed air.
INSPECTION
(1) Visually inspect the tappet the tappet socket,
stem, and face for excessive wear, cracks, or obvious
damage (Fig. 80).
(2) Measure the tappet stem diameter. Replace the
tappet if it falls below the minimum size (Fig. 80).
Fig. 77 Inserting the Trough - Typical
1 - TROUGH
Fig. 78 Secure Dowel/Tappet to Adjacent Cylinder -
typical
Fig. 79 Lift Dowel Rod to Disengage from Tappet -
typical
Fig. 80 Tappet Inspection
TAPPET STEM DIAMETER
15.936 mm (0.627 in.) MIN.
15.977 mm (0.629 in.) MAX.
DRENGINE 5.9L DIESEL 9 - 279

NOTE: If cylinders have ridges, the cylinders are
oversize and will more than likely need boring.
(8) Using a hammer and steel stamp, stamp the
cylinder number in the top of each piston. The front
of the piston is identified by a stamping on the top of
the piston. DO NOT stamp in the outside 5 mm (.197
in.) of the piston diameter. DO NOT stamp over the
piston pin.
(9) Mark the connecting rod and cap with the cor-
responding cylinder numbers.
(10) Remove the connecting rod bolts and rod caps.
Use care so the cylinder bores and connecting rods
are not damaged.
(11) Use a hammer handle or similar object to
push the piston and connecting rod through the cyl-
inder bore.
(12) Store the piston/rod assemblies in a rack.
CLEANINGÐPISTON AND CONNECTING ROD
CAUTION: DO NOT use bead blast to clean the pis-
tons. DO NOT clean the pistons and rods in an acid
tank.
PISTON
Clean the pistons and pins in a suitable solvent,
rinse in hot water and blow dry with compressed air.
Soaking the pistons over night will loosen most of the
carbon build up. De-carbon the ring grooves with a
broken piston ring and again clean the pistons in sol-
vent. Rinse in hot water and blow dry with com-
pressed air.
CONNECTING ROD
Clean the connecting rods in a suitable solvent,
rinse in hot water and blow dry with compressed air.
INSPECTION
INSPECTION - PISTONS
Inspect the pistons for damage and excessive wear.
Check top of the piston, ring grooves, skirt and pin
bore. Measure the piston skirt diameter. If the piston
is out of limits, replace the piston.
PISTON SKIRT DIAMETER (MIN.)
101.775 mm (4.006 in. )The upper groove only needs to be inspected for
damage. Use a new piston ring to measure the clear-
ance in the intermediate ring groove (Fig. 87). Mini-
mum clearance is 0.045 mm (0.0018 inch), maximum
clearance is 0.095 mm (.0037 inch). If the clearance
of the intermediate ring exceeds specifications,
replace the piston.
Use a new oil ring to measure the clearance in the
oil groove (Fig. 87). Minimum clearance is 0.040 mm
(0.0016 inch), maximum clearance is 0.085 mm
(.0033 inch). If the clearance exceeds specifications,
replace the piston.
Measure the pin bore (Fig. 88). The maximum
diameter is 40.012 mm (1.5753 inch), Minimum is
40.006 mm (1.575 inch). If the bore is over limits,
replace the piston.
Fig. 87 Intermediate and Oil Ring Clearances
1 - FEELER GAUGE
2 - RING
3 - PISTON
Fig. 88 Piston Pin Bore
1 - PISTON
2 - PIN BORE
9 - 282 ENGINE 5.9L DIESELDR
PISTON & CONNECTING ROD (Continued)

OIL COOLER & LINES
CLEANING
CLEANING AND INSPECTION
Clean the sealing surfaces.
Apply 483 kPa (70 psi) air pressure to the element
to check for leaks. If the element leaks, replace the
element.
OIL FILTER
REMOVAL
(1) Clean the area around the oil filter head.
Remove the filter from below using a cap-style filter
wrench.
(2) Clean the gasket surface of the filter head. The
filter canister O-Ring seal can stick on the filter
head. Make sure it is removed.
INSTALLATION
(1) Fill the oil filter element with clean oil before
installation. Use the same type oil that will be used
in the engine.
(2) Apply a light film of lubricating oil to the seal-
ing surface before installing the filter.
CAUTION: Mechanical over-tightening may distort
the threads or damage the filter element seal.
(3) Install the filter until it contacts the sealing
surface of the oil filter adapter. Tighten filter an
additional
1¤2turn.
OIL PAN
REMOVAL
(1) Disconnect the battery negative cables.
(2) Install engine support fixture # 8534.
(3) Raise vehicle on hoist.
(4) Disconnect starter cables from starter motor.
(5) Remove transmission and transfer case (if
equipped).
(6) Remove flywheel or flexplate.
(7) Remove starter motor (Refer to 8 - ELECTRI-
CAL/STARTING/STARTER MOTOR - REMOVAL)
and transmission adapter plate assembly.
WARNING: HOT OIL CAN CAUSE PERSONAL
INJURY.
(8) Drain the engine oil (Refer to 9 - ENGINE/LU-
BRICATION/OIL - STANDARD PROCEDURE).(9) Install the oil pan drain plug if sealing surface
is not damaged and tighten to 50 N´m (37 ft. lbs.)
torque.
(10) Remove oil pan bolts, break the pan to block
seal, and lower pan slightly and remove oil suction
tube fasteners.
(11) Remove oil pan and suction tube.
CLEANING
Remove all gasket material from the oil pan and
cylinder block sealing surfaces. Extra effort may be
required around T-joint areas. Clean oil pan and
flush suction tube with a suitable solvent.
INSPECTION
Inspect the oil pan, suction tube, and tube braces
for cracks and damage. Replace any defective compo-
nent. Inspect the oil drain plug and drain hole
threads. Inspect the oil pan sealing surface for
straightness. Repair any minor imperfections with a
ball-peen hammer. Do not attempt to repair an oil
pan by welding.
INSTALLATION
(1) Fill the T-joint between the pan rail/gear hous-
ing and pan rail/rear seal retainer with sealant. Use
MopartSilicone Rubber Adhesive Sealant or equiva-
lent.
(2) Place suction tube in oil pan and guide them
into place. Using a new tube to block gasket, install
and tighten the suction tube bolts by hand. Starting
with the oil pump inlet bolts, tighten the bolts to 24
N´m (18 ft. lbs.) torque. Tighten the remaining tube
brace bolts to 43 N´m (32 ft. lbs.) torque.
(3) Starting in the center and working outward,
tighten the oil pan bolts to 28 N´m (21 ft. lbs.)
torque.
(4) Install the flywheel housing assembly with the
starter motor attached and tighten bolts to 77 N´m
(57 ft. lbs.) torque.
(5) Connect starter motor cables.
(6) Install the flywheel or flexplate. Torque to 137
N´m (101 ft. lbs.).
(7) Install transmission and transfer case (if
equipped).
(8) Lower vehicle.
(9) Remove the engine support fixture # 8534.
(10) Install battery negative cables.
(11) Fill the crankcase with new engine oil.
(12) Start engine and check for leaks. Stop engine,
check oil level, and adjust, if necessary.
DRENGINE 5.9L DIESEL 9 - 293

OIL PRESSURE RELIEF VALVE
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove the threaded plug, spring and plunger
(Fig. 108). Insert a finger or a seal pick to lift the
plunger from the bore.
NOTE: If the plunger is stuck in the bore, it will be
necessary to remove the filter head.
CLEANING
(1) Clean the regulator spring and plunger with a
suitable solvent and blow dry with compressed air. If
the plunger bore requires cleaning, it is necessary to
remove the oil filter head to avoid getting debris into
the engine.
INSPECTION
Inspect the plunger and plunger bore for cracks
and excessive wear. Polished surfaces are acceptable.
Verify that the plunger moves freely in the bore.
Check the spring for height and load limitations
(Fig. 109). Replace the spring if out of limits shown
in the figure.
INSTALLATION
(1) Install the plunger, spring, and plug as shown
in (Fig. 108). Tighten the plug to 80 N´m (59 ft. lbs.)
torque.
(2) Connect the battery negative cables.
(3) Start the engine and verify that it has oil pres-
sure.
OIL PRESSURE SWITCH
REMOVAL
(1) Disconnect the battery negative cables.
(2) Disconnect the oil pressure switch connector.
(3) Using a suitable socket, remove the oil pres-
sure switch from the block (counter-clockwise).
INSTALLATION
(1) If the switch is not being replaced, replace and
lubricate the o-ring.
(2) Install the oil pressure switch and tighten to
18 N´m (159 in. lbs.) torque.
(3) Connect oil pressure switch connector.
(4) Connect the battery negative cables.
(5) Start engine and check for oil leaks at the
switch.
OIL PUMP
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove fan/drive assembly (Refer to 7 - COOL-
ING/ENGINE/RADIATOR FAN - REMOVAL).
(3) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(4) Remove the fan support/hub assembly.
(5) Remove crankshaft damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL) and speed indicator ring.
(6) Remove power steering pump.
(7) Remove accessory drive belt tensioner.
(8) Remove the gear housing cover (Refer to 9 -
ENGINE/VALVE TIMING/GEAR HOUSING COVER
- REMOVAL).
Fig. 108 Oil Pressure Regulator
1 - OIL FILTER
2 - PLUG
3 - GASKET
4 - SPRING
5 - VALVE
Fig. 109 Oil Pressure Regulator Spring Check
9 - 294 ENGINE 5.9L DIESELDR

(9) Remove the four mounting bolts and pull the
oil pump from the bore in the cylinder block (Fig.
110).
CLEANING
Clean all parts in solvent and dry with compressed
air. Clean the old sealer residue from the back of the
gear housing cover and front of the gear housing.
INSPECTION
Disassemble and inspect the oil pump as fol-
lows:
(1) Visually inspect the lube pump gears for chips,
cracks or excessive wear.
(2) Remove the back plate (Fig. 111).
(3) Mark TOP on the gerotor planetary using a felt
tip pen (Fig. 111).
(4) Remove the gerotor planetary (Fig. 111).
Inspect for excessive wear or damage. Inspect the
pump housing and gerotor drive for damaged and
excessive wear.
(5) Install the gerotor planetary in the original
position.
(6) Measure the tip clearance (Fig. 112). Maximum
clearance is 0.1778 mm (0.007 inch). If the oil pump
is out of limits, replace the pump.
(7) Measure the clearance of the gerotor drive/
gerotor planetary to port plate (Fig. 113). Maximum
clearance is 0.127 mm (0.005 inch). If the oil pump is
out of limits, replace the pump.
Fig. 110 Oil Pump Removal/Installation
1 - OIL PUMP
2 - BOLT (4)
Fig. 111 Gerotor Planetary and Gerotor
1 - OIL PUMP BACK PLATE
2 - GEROTOR
3 - GEROTOR PLANETARY
Fig. 112 Measuring Tip Clearance
1 - FEELER GAUGE
Fig. 113 Measuring Gerotor to Port Plate Clearance
1 - PORT PLATE
2 - GEROTOR
DRENGINE 5.9L DIESEL 9 - 295
OIL PUMP (Continued)