1998 DODGE RAM 1500 Cooling

(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)

PISTON & CONNECTING ROD
DESCRIPTION
PISTONS
The piston (Fig. 85) is constructed of aluminum
and is gravity cast, free floating design. The piston
incorporates a centrally located high swirl combus-
tion bowl, and utilizes a ªkeystoneº style top com-
pression ring (Fig. 86), and a ªTapered Faceº
intermediate ring (Fig. 86), for superior cylinder wall
scraping. Piston cooling nozzles cool the piston and
pin with engine oil supplied by the crankshaft main
journals. High horsepower pistons are gallery cooled
and utilize J-jet piston cooling nozzles. Pistons are
directional in order to provide clearance to piston
cooling nozzles.
CONNECTING RODS
The connecting rods are a split angle design. They
have a pressed-in-place wrist pin bushing that is
lubricated by piston cooling nozzle oil spray.
Machined connecting rods are no longer used
in the diesel engine. Do not install machined
connecting rods into an engine that has frac-
tured split connecting rods.
Fractured split connecting rods are first manufac-
tured as a single piece and then fractured into two
pieces. Fractured split connecting rods can be identi-
fied by a rough and irregular surface at the connect-
ing rod split face. To properly assemble the rod cap to
the connecting rod, the bearing tangs on the connect-
ing rod and cap must be located on the same side of
the rod. The long end of the connecting rod must be
assembled on the intake or camshaft side of the
engine.
Each matched fractured split connecting rod and
cap is an assembly and are not interchangeable. If a
connecting rod or cap is damaged, the entire assem-
bly must be replaced.
STANDARD PROCEDURE - HEAD GASKET
SELECTION
(1) Measure piston protrusion for all six pistons.
(2) Calculate the average piston protrusion. Maxi-
mum allowable protrusion is 0.516 mm (0.020 inch).
NOTE: There are two different head gaskets avail-
able. One gasket is for Average piston protrusion
less than 0.30 mm (0.011 inch). The other gasket is
for Average piston protrusion greater than 0.30 mm
(0.011 inch)
REMOVAL
(1) Disconnect the battery cables.
(2) Remove the cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - REMOVAL).
(3) Remove the oil pan and suction tube (Refer to 9
- ENGINE/LUBRICATION/OIL PAN - REMOVAL).
(4) Remove bolts and the block stiffener.
(5) Using Miller Tool 7471-B crankshaft barring
tool, rotate the crankshaft so all of the pistons are
below TDC.
(6) Before removing the piston(s) from the bore(s):
(a) Remove any carbon ridge formations or
deposits at the top of the bore with a dull scraper
or soft wire brush.
(b) If cylinder bore wear ridges are found, use a
ridge reamer to cut the ridge from the bore. DO
NOT remove more metal than necessary to remove
the ridge.
(7) Remove the J-jet cooling nozzles, if equipped.
Fig. 85 Piston - Typical
Fig. 86 Piston Ring Identification
DRENGINE 5.9L DIESEL 9 - 281

(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)

INSTALLATION
(1) Install speed indicator ring.
NOTE: The speed indicator ring is located over a
dowel pin.
(2) Install the crankshaft damper and bolts.
Tighten bolts to 40 N´m (30 ft. lbs.) torque, plus an
additional 60É.
NOTE: The damper must be installed so the hole is
located over the dowel pin.
(3) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
FRONT MOUNT
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove the viscous fan/drive assembly (Refer
to 7 - COOLING/ENGINE/RADIATOR FAN -
REMOVAL).
(3) Raise vehicle on hoist.
(4) Install engine support fixture tool# 8534 and
steel bracket tool # 8534A
(5) Loosen the thru-bolt and nut.
(6) Lift the engine SLIGHTLY and remove the
insulator to block bolts (Fig. 101) (Fig. 100).
(7) Remove the insulator from the vehicle.
Fig. 99 Inspect Damper Rubber Member
Fig. 100 RH Insulator
1 - Mount
2 - Insulator
3 - Bolt
Fig. 101 LH Insulator
1 - Bolt
2 - Insulator
3 - Mount
9 - 286 ENGINE 5.9L DIESELDR
VIBRATION DAMPER (Continued)

INSTALLATION
(1) With engine raised SLIGHTLY, position the
insulator to the mount (Fig. 102) (Fig. 103). Install
the bolts and torque to specification.
(2) Lower the engine using tool # 8534, while guid-
ing the mount and thru-bolt into the frame mounted
support cushion brackets.
(3) Install the thru-bolt nut and tighten the nut to
95 N´m (70 ft. lbs.) torque.(4) Remove the engine support fixture tool #8534.
(5) Lower the vehicle.
(6) Install the viscous fan/drive assembly (Refer to
7 - COOLING/ENGINE/RADIATOR FAN - INSTAL-
LATION).
(7) Connect the battery negative cables.
Fig. 102 LH Insulator
1 - Bolt
2 - Insulator
3 - Mount
Fig. 103 RH Insulator
1 - Mount
2 - Insulator
3 - Bolt
DRENGINE 5.9L DIESEL 9 - 287
FRONT MOUNT (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

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)