
CONNECTING RODS
The connecting rods are a split angle design (Fig.
89). They have a pressed-in-place wrist pin bushing
that is lubricated by piston cooling nozzle oil spray.
There are two different types of connecting rods:
machined and fractured split. The main different
between the two styles is the surface finish on the
connecting rod split face.
Machined connecting rods can be identified by a
machined surface at the connecting rod and cap split
face. Machined connecting rods have numbers
stamped on the rod cap and connecting rod near the
parting line. The number stamped on the connecting
rod must match the number stamped on the rod cap
and be installed on the camshaft or intake side of the
engine.
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.
Measuring methods and specifications are common
between fractured split and machined connecting
rods.
Both fractures split and machined connecting rods
and caps are machined as an assembly and are not
interchangeable. If a connecting rod or cap is dam-
aged, the entire assembly must be replaced.
Machined and fractured split connecting rods cannot
be used in the same engine.
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 nozzels, if equipped.
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.
Fig. 89 Connecting Rod
9 - 330 ENGINE 5.9L DIESELDR
PISTON & CONNECTING ROD (Continued)

Inspect the piston pin for nicks, gouges and exces-
sive wear. Measure the pin diameter (Fig. 93). 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. 94). 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) Compress the rings using a piston ring com-
pressor tool (Fig. 95). 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.
(4) Bar the crankshaft so the rod journal for the
piston to be installed is at BDC (Bottom Dead Cen-
ter) - (Fig. 96).
(5) Make sure the front of the piston is oriented
properly according to the marking on the top of the
piston and the numbers on the rod and cap are ori-
ented as illustrated.
(6) 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. In this position the numbers on the connect-
ing rod should be facing the intake or camshaft side
of the engine, and the rod bolt hex heads toward the
oil cooler. Use care when you install the piston and
connecting rod so the cylinder bore is not damaged. If
a fractured split connecting rod is being installed, the
long side of the connecting rod must be installed on
the intake side of the engine.
(7) 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.
Fig. 93 Piston Pin Diameter
1 - PISTON PIN
Fig. 94 Connecting Rod Pin Bore
1 - CONNECTING ROD
Fig. 95 Piston Ring Compressor Tool
1 - PISTON RING COMPRESSOR TOOL
Fig. 96 Piston/Rod Assembly at BDC
9 - 332 ENGINE 5.9L DIESELDR
PISTON & CONNECTING ROD (Continued)

(8) Use clean engine oil to lubricate the threads
and under the heads of the connecting rod bolts.
(9)For machined connecting rods,the number
stamped on the rod cap at the parting line must
match and be installed towards the intake or cam-
shaft side of the engine (Fig. 97).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 oil
cooler side of the engine if properly installed.
(10) 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.
(11) 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.
(12) Measure the side clearance between the con-
necting rod and the crankshaft (Fig. 98). DO NOT
measure the clearance between the cap and crank-
shaft.
(13) Install J-jet piston cooling nozzles if equipped.
(14) Install block stiffener. Torque to 43 N´m (32 ft.
lbs.).
(15) Install the suction tube and oil pan (Refer to 9
- ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).(16) Install the cylinder head onto the engine
(Refer to 9 - ENGINE/CYLINDER HEAD - INSTAL-
LATION).
(17) Install a new filter and fill the crankcase with
new engine oil.
(18) 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. 99).
Fig. 97 Correct Rod Cap Installation
Fig. 98 Side Clearance between Connecting
Rod/Crankshaft
1 - FEELER GAUGE
´Minimum 0.33 mm (.013 inch)
´MAX. 0.10mm (.004 inch)
Fig. 99 Piston Ring Identification
DRENGINE 5.9L DIESEL 9 - 333
PISTON & CONNECTING ROD (Continued)

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. 104). 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. 105).
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. 107) (Fig. 106).
(7) Remove the insulator from the vehicle.
INSTALLATION
(1) With engine raised SLIGHTLY, position the
insualtor to the mount (Fig. 108) (Fig. 109). Install
the bolts and torque to specification.
(2)
(3) Lower the engine using tool # 8534, while guid-
ing the mount and thru-bolt into the frame mounted
support cushion brackets.
(4) Install the thru-bolt nut and tighten the nut to
88 N´m (65 ft. lbs.) torque.
(5) Remove the engine support fixture tool #8534.
(6) Lower the vehicle.
(7) Install the viscous fan/drive assembly (Refer to
7 - COOLING/ENGINE/RADIATOR FAN - INSTAL-
LATION).
(8) Connect the battery negative cables.
Fig. 104 Inspect Index Lines for Alignment
1 - INDEX LINES
2 - HUB
3 - INERTIA MEMBER
Fig. 105 Inspect Damper Rubber Member
DRENGINE 5.9L DIESEL 9 - 335

REAR MOUNT
REMOVAL
(1) Raise the vehicle on a hoist.
(2) Position a transmission jack in place.
(3) Remove support cushion stud nuts (Fig. 110).
(4) Raise rear of transmission and engine
SLIGHTLY.
(5) Remove the bolts holding the support cushion
to the transmission support bracket. Remove the sup-
port cushion.
(6) If necessary, remove the bolts holding the
transmission support bracket to the transmission.
INSTALLATION
(1) If removed, position the transmission support
bracket to the transmission. Install new attaching
bolts and tighten to 102 N´m (75 ft. lbs.) torque.
(2) Position support cushion to transmission sup-
port bracket. Install stud nuts and tighten to 47 N´m
(35 ft. lbs.) torque.
(3) Using the transmission jack, lower the trans-
mission and support cushion onto the crossmember
(Fig. 110).
(4) Install the support cushion bolts and tighten to
47 N´m (35 ft. lbs.) torque.
(5) Remove the transmission jack.
(6) Lower the vehicle.
LUBRICATION
DESCRIPTION
NOTE: Refer to (Fig. 111) and (Fig. 112) 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
Fig. 110 Engine Rear Support Cushion Assembly
DRENGINE 5.9L DIESEL 9 - 337

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 therocker 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. 111) and
(Fig. 112).
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.
9 - 338 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 starter motor (Refer to 8 - ELECTRI-
CAL/STARTING/STARTER MOTOR - REMOVAL)
and transmission adapter plate assembly.
(6) Remove transmission and transfer case (if
equipped).
(7) Remove flywheel or flexplate.
(8) Remove the transmission adapter plate.
WARNING: HOT OIL CAN CAUSE PERSONAL
INJURY.
(9) Drain the engine oil (Refer to 9 - ENGINE/LU-
BRICATION/OIL - STANDARD PROCEDURE).(10) Install the oil pan drain plug if sealing sur-
face is not damaged and tighten to 50 N´m (57 ft.
lbs.) torque.
(11) Remove oil pan bolts, break the pan to block
seal, and lower pan slightly and remove oil suction
tube fasteners.
(12) 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.
9 - 342 ENGINE 5.9L DIESELDR

OIL PRESSURE RELIEF VALVE
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove the threaded plug, spring and plunger
(Fig. 114). 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. 115). Replace the spring if out of limits shown
in the figure.
INSTALLATION
(1) Install the plunger, spring, and plug as shown
in (Fig. 114). Tighten the plug to 80 N´m (60 ft. lbs.)
torque.
(2) Connect the battery negative cables.
(3) Start the engine and verify that it has oil pres-
sure.
OIL PRESSURE SENSOR/
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 hydraulic pump.
(7) Remove accessory drive belt tensioner.
(8) Remove the gear housing cover (Refer to 9 -
ENGINE/VALVE TIMING/GEAR HOUSING COVER
- REMOVAL).
Fig. 114 Oil Pressure Regulator
1 - OIL FILTER
2 - PLUG
3 - GASKET
4 - SPRING
5 - VALVE
Fig. 115 Oil Pressure Regulator Spring Check
DRENGINE 5.9L DIESEL 9 - 343