1998 DODGE RAM 1500 oil

Inspect the piston pin for nicks, gouges and exces-
sive wear. Measure the pin diameter (Fig. 89). The
minimum diameter is 39.990 mm (1.5744 inch), max-
imum 40.003 mm (1.5749 inch). If the diameter is out
of limits, replace the pin.
INSPECTIONÐCONNECTING ROD
Inspect the connecting rod for damage and wear.
The I-Beam section of the connecting rod cannot have
dents or other damage. Damage to this part can
cause stress risers which will progress to breakage.
Measure the connecting rod pin bore (Fig. 90). The
maximum diameter is 40.042 mm (1.5765 inch), min-
imum diameter is 40.019 mm (1.5756 inch). If out of
limits, replace the connecting rod.
INSTALLATION
(1) Lubricate the cylinder bores with clean engine
oil.
(2) Generously lubricate the rings and piston
skirts with clean engine oil.(3) Orientate the rings on the piston (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON RINGS - STAN-
DARD PROCEDURE).
(4) Compress the rings using a piston ring com-
pressor tool (Fig. 91). If using a strap-type ring com-
pressor, make sure the inside end of the strap does
not hook on a ring gap and break the ring.
(5) Bar the crankshaft so the rod journal for the
piston to be installed is at BDC (Bottom Dead Cen-
ter) - (Fig. 92).
(6) Make sure the front of the piston is oriented
properly according to the marking on the top of the
piston and the connecting rod is oriented properly.
(7) Position the piston and rod assembly into the
cylinder bore with the front of the piston oriented
properly according to the stamping in the top of the
piston. Use care when you install the piston and con-
necting rod so the cylinder bore is not damaged. The
long side of the connecting rod must be installed on
the intake side of the engine.
(8) Push the piston into the bore until the top of
the piston is approximately 50 mm (2 inch) below the
top of the block. Carefully pull the connecting rod
onto the crankshaft journal.
(9) Use clean engine oil to lubricate the threads
and under the heads of the connecting rod bolts.
Fig. 89 Piston Pin Diameter
1 - PISTON PIN
Fig. 90 Connecting Rod Pin Bore
1 - CONNECTING ROD
Fig. 91 Piston Ring Compressor Tool
1 - PISTON RING COMPRESSOR TOOL
Fig. 92 Piston/Rod Assembly at BDC
DRENGINE 5.9L DIESEL 9 - 283
PISTON & CONNECTING ROD (Continued)

(10)For fractured/split type connecting rods,
the long end of the rod must be installed towards the
intake side of the engine.
(a) The connecting rod split/face must face
toward the same side as the piston notch feature
on the skirt. The split face will face toward the
exhaust side of the engine if properly installed.
(11) Install the rod cap and bolts to the connecting
rod. Tighten the connecting rod bolts evenly in 3
steps.
²Tighten the bolts to 30 N´m (22 ft. lbs.) torque.
²Tighten the bolts to 60 N´m (44 ft. lbs.) torque.
²Rotate 60É clockwise.
(12) The crankshaft must rotate freely. Check for
freedom of rotation as the caps are installed. If the
crankshaft does not rotate freely, check the installa-
tion of the rod bearing and the bearing size.
(13) Measure the side clearance between the con-
necting rod and the crankshaft. DO NOT measure
the clearance between the cap and crankshaft.
(14) Install J-jet piston cooling nozzles if equipped.
(15) Install block stiffener. Torque to 43 N´m (32 ft.
lbs.).
(16) Install the suction tube and oil pan (Refer to 9
- ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
(17) Install the cylinder head onto the engine
(Refer to 9 - ENGINE/CYLINDER HEAD - INSTAL-
LATION).
(18) Install a new filter and fill the crankcase with
new engine oil.Prefill the filter with clean oil.
(19) Connect the battery negative cables and start
engine.
PISTON RINGS
STANDARD PROCEDURE - PISTON RING
FITTING
(1) Determine the piston diameter and obtain the
appropriate ring set. The piston rings can be identi-
fied as shown in (Fig. 93).
(2) Position each ring in the cylinder and use a
piston to square it with the bore at a depth of 89.0
mm (3.5 inch) - (Fig. 94).(3) Use a feeler gauge to measure the piston ring
gap.
PISTON RING GAP CHART
TOP RING 0.26 - 0.36 mm(0.010 - 0.014
in.)
INTERMEDIATE
RING0.85-1.15 mm(0.033 - 0.045
in.)
OIL CONTROL
RING0.25-0.55 mm(0.010 - 0.022
in.)
Fig. 93 Piston Ring Identification
Fig. 94 Position of Ring in Cylinder Bore
1 - PISTON
2 - CYLINDER BORE
3 - DEPTH
9 - 284 ENGINE 5.9L DIESELDR
PISTON & CONNECTING ROD (Continued)

(4) The top surface of all of the rings are identified
with the word TOP or the supplier's MARK. Assem-
ble the rings with the word TOP or the supplier's
MARK up.
(5) Position the oil ring expander in the oil control
ring groove (bottom groove).
(6) Install the oil control ring with the end gap
OPPOSITE the ends on the expander (Fig. 95).
(7) Install the intermediate piston ring in the sec-
ond groove.
(8) Install the top piston ring in the top groove
(Fig. 96).
(9) Position the rings as shown in (Fig. 97).
VIBRATION DAMPER
REMOVAL
(1) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).(2) Remove the four (4) damper to crankshaft bolts
and remove damper and speed indicator ring.
INSPECTION
(1) Inspect the damper hub for cracks and replace
if any are found.
(2) Inspect the index lines on the damper hub and
the inertia member (Fig. 98). If the lines are more
than 1.59 mm (1/16 in.) out of alignment, replace the
damper.
(3) Inspect the rubber member for deterioration or
missing segments (Fig. 99).Fig. 95 Oil Control Ring/Expander Location in
Groove
1 - OIL CONTROL RING
2 - EXPANDER
3 - PISTON
Fig. 96 Piston Ring Installation Tool
1 - PISTON RING INSTALLATION TOOL
Fig. 97 Piston Ring Orientation
1 - TOP RING
2 - INTERMEDIATE RING
3 - OIL CONTROL RING
Fig. 98 Inspect Index Lines for Alignment
1 - INDEX LINES
2 - HUB
3 - INERTIA MEMBER
DRENGINE 5.9L DIESEL 9 - 285
PISTON RINGS (Continued)

LUBRICATION
DESCRIPTION
NOTE: Refer to (Fig. 105) and (Fig. 106) for circuit
illustrations.
A gear driven gerotor type oil pump is mounted
behind the front gear cover in the lower right portion
on the engine.
OPERATION
A gerotor style oil pump draws oil from the crank-
case through the suction tube and delivers it through
the block where it enters the oil cooler cover and
pressure regulator valve. When oil pressure exceeds
517 kPa (75 PSI), the valve opens exposing the dump
port, which routes excess oil back to the oil pump.
At the same time, oil is directed to a cast in pas-
sage in the oil cooler cover, leading to the oil cooler
element. As the oil travels through the element
plates, it is cooled by engine coolant traveling past
the outside of the plates. It is then routed to the oil
filter head and through a full flow oil filter. If a
plugged filter is encountered, the filter by-pass valve
opens, allowing unfiltered oil to lubricate the engine.
This condition can be avoided by frequent oil and fil-
ter changes, per the maintenance schedules found in
the owners manual. The by-pass valve is calibrated
to open when it sees a pressure drop of more than
345 kPa (50 psi) across the oil filter.
The oil filter head then divides the oil between the
engine and the turbocharger. The turbocharger
receives filtered, cooled and pressurized oil through a
supply line from the filter head. The oil lubricates
the turbocharger and returns to the pan by way of a
drain tube connecting the bottom of the turbocharger
to a pressed in tube in the cylinder block.
Oil is then carried across the block to an angle
drilling which intersects the main oil rifle. The main
oil rifle runs the length of the block and delivers oil
to the crankshaft main journals and valve train. Oil
travels to the crankshaft through a series of transfer
drillings (one for each main bearing) and lubricates a
groove in the main bearing upper shell. From there
another drilling feeds the camshaft main journals.The saddle jet piston cooling nozzles are also sup-
plied by the main bearing upper shell. J-jet piston
cooling nozzles are supplied by a separate oil rifle.
Plugs are used in place of saddle jets when J-jets are
used. J-jet hole locations are plugged when saddle jet
cooling nozzles are used. Crankshaft internal cross-
drillings supply oil to the connecting rod journals.
Another series of transfer drillings intersecting the
main oil rifle supply the valve train components. Oil
travels up the drilling, through a hole in the head
gasket, and through a drilling in the cylinder head
(one per cylinder), where it enters the rocker arm
pedestal and is divided between the intake and
exhaust rocker arm. Oil travels up and around the
rocker arm mounting bolt, and lubricates the rocker
shaft by cross drillings that intersect the mounting
bolt hole. Grooves at both ends of the rocker shaft
supply oil through the rocker arm where the oil trav-
els to the push rod and socket balls (Fig. 105) and
(Fig. 106).
DIAGNOSIS AND TESTINGÐENGINE OIL
PRESSURE
(1) Remove the 1/8 npt plug from the top of the oil
filter housing.
(2) Install Oil Pressure Line and Gauge Tool
C-3292 with a suitable adapter.
(3) Start engine and warm to operating tempera-
ture.
(4) Record engine oil pressure and compare with
engine oil pressure chart.
CAUTION: If engine oil pressure is zero at idle, DO
NOT RUN THE ENGINE.
Engine Oil Pressure (MIN)
At Idle 68.9 kPa (10 psi)
At 2500 rpm 206.9 kPa (30 psi)
If minimum engine oil pressure is below these
ranges, (Refer to 9 - ENGINE - DIAGNOSIS AND
TESTING).
(5) Remove oil pressure gauge and install the 1/8
npt plug.
DRENGINE 5.9L DIESEL 9 - 289

Fig. 105 Lubrication System Circulation
1 - TO FILTER
2 - FROM FILTER
3 - TO MAIN OIL RIFLE
4 - CLOSED
5 - OPEN
6 - TO COOLER7 - FROM PUMP
8 - CLOSED
9 - OPEN
10 - OIL DRAINS BACK TO THE PUMP
11 - OIL DRAIN
12 - OIL SUPPLY
9 - 290 ENGINE 5.9L DIESELDR
LUBRICATION (Continued)

OIL
STANDARD PROCEDURE
STANDARD PROCEDURE - ENGINE OIL LEVEL
CAUTION: Do not overfill crankcase with engine oil,
oil foaming and oil pressure loss can result.
To ensure proper lubrication of an engine, the
engine oil must be maintained at an acceptable level.
The acceptable oil level is in the SAFE RANGE on
the engine oil dipstick (Fig. 107).
(1) Position vehicle on level surface.
(2) With engine OFF, allow approximately 15 min-
utes for oil to settle to bottom of crankcase, remove
engine oil dipstick.
(3) Wipe dipstick clean.
(4) Replace dipstick and verify it is seated in the
tube.
(5) Remove dipstick, with handle held above the
tip, take oil level reading.
(6) Add oil only if level is below the SAFE RANGE
area on the dipstick.
(7) Replace dipstick
STANDARD PROCEDURE - ENGINE OIL
SERVICE
WARNING: HOT OIL CAN CAUSE PERSONAL
INJURY.
NOTE: Change engine oil and filter at intervals
specified in the owner's manual.
(1) Operate the engine until the water tempera-
ture reaches 60ÉC (140ÉF). Shut the engine off.
(2) Use a container that can hold at least 14 liters
(15 quarts) to hold the used oil. Remove the oil drain
plug and drain the used engine oil into the container.
(3) Always check the condition of the used oil. This
can give you an indication of engine problems that
might exist.
²Thin, black oil indicates fuel dilution.
²Milky discoloration indicates coolant dilution.
(4) Clean the area around the oil filter head.
Remove the filter (Refer to 9 - ENGINE/LUBRICA-
TION/OIL FILTER - REMOVAL).
(5) Install new oil filter (Refer to 9 - ENGINE/LU-
BRICATION/OIL FILTER - INSTALLATION).
(6) Clean the drain plug and the sealing surface of
the pan. Check the condition of the threads and seal-
ing surface on the oil pan and drain plug.
(7) Install the drain plug. Tighten the plug to 50
N´m (37 ft. lbs.) torque.
(8) Use only High-Quality Multi-Viscosity lubricat-
ing oil in the Cummins Turbo Diesel engine. Choose
the correct oil for the operating conditions (Refer to
LUBRICATION & MAINTENANCE/FLUID TYPES -
DESCRIPTION).
(9) Fill the engine with the correct grade of new oil
(Refer to LUBRICATION & MAINTENANCE/FLUID
CAPACITIES - SPECIFICATIONS).
(10) Start the engine and operate it at idle for sev-
eral minutes. Check for leaks at the filter and drain
plug.
(11) Stop engine. Wait 15 minutes to allow the oil
to drain back to the pan and check the level again.
USED ENGINE OIL DISPOSAL
Care should be exercised when disposing of used
engine oil after it has been drained from a vehicle's
engine.
1 - ROCKER ARM
2 - ROCKER SHAFT
3 - PEDESTAL
4 - FROM MAIN OIL RIFLE
5 - TO VALVE TRAIN
6 - MAIN OIL RIFLE
7 - FROM MAIN OIL RIFLE8 - TO CAMSHAFT
9 - TO PISTON COOLING NOZZLE
10 - FROM OIL COOLER
11 - CRANKSHAFT MAIN JOURNAL
12 - ROD JOURNAL
13 - TO ROD BEARING
14 - MAIN OIL RIFLE
Fig. 107 Oil Level Indicator (Dipstick)
1 - ADD OIL MARK
2 - O-RING
3 - SAFE RANGE
9 - 292 ENGINE 5.9L DIESELDR
LUBRICATION (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