2003 DODGE RAM engine

(4) Raise dowel rod (disengage from tappet) and
allow tappet to fall into trough (Fig. 81).
(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. 82).
(2) Measure the tappet stem diameter. Replace the
tappet if it falls below the minimum size (Fig. 82).
INSTALLATION
(1) Insert the trough the full length of the cam-
shaft bore. Again, make sure the cap end goes in first
and the open side faces up (towards tappets).
(2) Lower the tappet installation tool through the
push rod hole (Fig. 83) and into the trough.
(3) Retrieve the tappet installation tool using the
hooked rod provided with the tool kit (Fig. 84).
Fig. 83 Insert Installation Tool through Push Rod
Hole - Typical
Fig. 84 Retrieve Tappet Installation Tool through
Cam Bore - Typical
Fig. 81 Lift Dowel Rod to Disengage from Tappet -
typical
Fig. 82 Tappet Inspection
TAPPET STEM DIAMETER
15.936 mm (0.627 in.) MIN.
15.977 mm (0.629 in.) MAX.
9 - 328 ENGINE 5.9L DIESELDR
SOLID LIFTERS/TAPPETS (Continued)

(4) Lubricate the tappet with clean engine oil or
suitable equivalent and install the tappet to the
installation tool (Fig. 85).
(5) Pull the tappet up and into position (Fig. 85). If
difficulty is experienced getting the tappet to make
the turn into the tappet bore, wiggle the trough
whilegentlypulling up on the tappet.
(6) With the tappet in place, rotate the trough one
half turn so the open side is down (toward crank-
shaft) (Fig. 86).
(7) Remove the tappet installation tool from the
tappet.
(8) Re-install a dowel rod and secure the rod with
a rubber band.
(9) Rotate the trough one half turn and repeat the
procedure for the remaining tappets.
(10) Install the camshaft (Refer to 9 - ENGINE/
ENGINE BLOCK/CAMSHAFT & BEARINGS (IN
BLOCK) - INSTALLATION).PISTON & CONNECTING ROD
DESCRIPTION
PISTONS
The piston (Fig. 87) 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. 88), and a ªTapered Faceº
intermediate ring (Fig. 88), 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.
Fig. 85 Insert Tool and Pull Tappet Into Place -
Typical
Fig. 86 Rotate Trough One Half Turn (180É) - Typical
Fig. 87 Piston - Typical
Fig. 88 Piston Ring Identification
DRENGINE 5.9L DIESEL 9 - 329
SOLID LIFTERS/TAPPETS (Continued)

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)

(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
INSPECTIONÐPISTONS
Inspect the pistons for damage and excessive wear.
Check top of the piston, ring grooves, skirt and pin
bore. Measure the piston skirt diameter (Fig. 90). If
the piston is out of limits, replace the piston.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. 91). 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. 91). 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. 92). 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. 90 Piston Skirt Diameter
PISTON SKIRT DIAMETER (MIN.)
101.887 mm (4.011 in. )
Fig. 91 Intermediate and Oil Ring Clearances
1 - FEELER GAUGE
2 - RING
3 - PISTON
Fig. 92 Piston Pin Bore
1 - PISTON
2 - PIN BORE
DRENGINE 5.9L DIESEL 9 - 331
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)

(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. 100).
(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.)
(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. 101).
(7) Install the intermediate piston ring in the sec-
ond groove.
(8) Install the top piston ring in the top groove
(Fig. 102).
(9) Position the rings as shown in (Fig. 103).
Fig. 100 Position of Ring in Cylinder Bore
1 - PISTON
2 - CYLINDER BORE
3 - DEPTH
Fig. 101 Oil Control Ring/Expander Location in
Groove
1 - OIL CONTROL RING
2 - EXPANDER
3 - PISTON
Fig. 102 Piston Ring Installation Tool
1 - PISTON RING INSTALLATION TOOL
Fig. 103 Piston Ring Orientation
1 - TOP RING
2 - INTERMEDIATE RING
3 - OIL CONTROL RING
9 - 334 ENGINE 5.9L DIESELDR
PISTON RINGS (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