PISTON & CONNECTING ROD
DESCRIPTION
CAUTION: Do not use a metal stamp to mark con-
necting rods as damage may result, instead use ink
or a scratch awl.
The pistons are made of a high strength aluminum
alloy. The anodized top ring groove and crown has
been replaced with a coated top ring that is blue in
color on the bottom surface. Piston skirts are coated
with a solid lubricant (Molykote) to reduce friction
and provide scuff resistance. The connecting rods are
made of forged powdered metal, with a ªfractured
capº design. A pressed fit piston pin is used to attach
the piston and connecting rod.
STANDARD PROCEDURE - PISTON FITTING
(1) To correctly select the proper size piston, a cyl-
inder bore gauge, capable of reading in 0.003 mm (
.0001 in.) INCREMENTS is required. If a bore gauge
is not available, do not use an inside micrometer.
(2) Measure the inside diameter of the cylinder
bore at a point 38.0 mm (1.5 inches) below top of
bore. Start perpendicular (across or at 90 degrees) to
the axis of the crankshaft at point A and then take
an additional bore reading 90 degrees to that at point
B (Fig. 72).
(3) The coated pistons will be serviced with the
piston pin and connecting rod pre-assembled.
(4) The coating material is applied to the piston
after the final piston machining process. Measuring
the outside diameter of a coated piston will not pro-
vide accurate results (Fig. 71). Therefore measuring
the inside diameter of the cylinder bore with a dial
Bore Gauge isMANDATORY. To correctly select the
proper size piston, a cylinder bore gauge capable of
reading in 0.003 mm (.0001 in.) increments is
required.
(5) Piston installation into the cylinder bore
requires slightly more pressure than that required
for non-coated pistons. The bonded coating on the
piston will give the appearance of a line-to-line fit
with the cylinder bore.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the following components:
²Oil pan and gasket/windage tray (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - REMOVAL).
²Cylinder head covers (Refer to 9 - ENGINE/
CYLINDER HEAD/CYLINDER HEAD COVER(S) -
REMOVAL) and (Refer to 9 - ENGINE/CYLINDER
HEAD/CYLINDER HEAD COVER(S) - REMOVAL).²Timing chain cover (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT / CHAIN COVER(S)
- REMOVAL).
²Cylinder head(s) (Refer to 9 - ENGINE/CYLIN-
DER HEAD - REMOVAL) and (Refer to 9 - ENGINE/
CYLINDER HEAD - REMOVAL).
(3) If necessary, remove top ridge of cylinder bores
with a reliable ridge reamer before removing pistons
from cylinder block.Be sure to keep tops of pis-
Fig. 71 DO NOT MEASURE MOLY COATED PISTON
1 - MOLY COATED
2 - MOLY COATED
Fig. 72 BORE GAUGE - TYPICAL
1 - FRONT
2 - BORE GAUGE
3 - CYLINDER BORE
4 - 38 MM (1.5 in)
DRENGINE - 4.7L 9 - 139
tons covered during this operation.Pistons and
connecting rods must be removed from top of cylinder
block. When removing piston and connecting rod
assemblies from the engine, rotate crankshaft so the
each connecting rod is centered in cylinder bore.
CAUTION: DO NOT use a number stamp or a punch
to mark connecting rods or caps, as damage to
connecting rods could occur
NOTE: Connecting rods and bearing caps are not
interchangeable and should be marked before
removing to ensure correct reassembly.
(4) Mark connecting rod and bearing cap positions
using a permanent ink marker or scribe tool (Fig.
73).
CAUTION: Care must be taken not to damage the
fractured rod and cap joint face surfaces, as engine
damage may occur.
(5) Remove connecting rod cap. Install Special Tool
8507 Connecting Rod Guides into the connecting rod
being removed. Remove piston from cylinder bore.
Repeat this procedure for each piston being removed.
CAUTION: Care must be taken not to nick crank-
shaft journals, as engine damage may occur
(6) Immediately after piston and connecting rod
removal, install bearing cap on the mating connect-
ing rod to prevent damage to the fractured cap and
rod surfaces.
(7) Carefully remove piston rings from piston(s),
starting from the top ring down.CLEANING
CAUTION: DO NOT use a wire wheel or other abra-
sive cleaning devise to clean the pistons or con-
necting rods. The pistons have a Moly coating, this
coating must not be damaged.
(1) Using a suitable cleaning solvent clean the pis-
tons in warm water and towel dry.
(2) Use a wood or plastic scraper to clean the ring
land grooves.
CAUTION: DO NOT remove the piston pin from the
piston and connecting rod assembly.
INSPECTION
Check the connecting rod journal for excessive
wear, taper and scoring (Refer to 9 - ENGINE/EN-
GINE BLOCK/CONNECTING ROD BEARINGS -
STANDARD PROCEDURE).
Check the connecting rod for signs of twist or bend-
ing.
Check the piston for taper and elliptical shape
before it is fitted into the cylinder bore (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON & CONNECT-
ING ROD - STANDARD PROCEDURE).
Check the piston for scoring, or scraping marks in
the piston skirts. Check the ring lands for cracks
and/or deterioration.
INSTALLATION
(1) Before installing piston and connecting rod
assemblies into the bore, install the piston rings.
(2) Immerse the piston head and rings in clean
engine oil. Position a ring compressor over the piston
and rings. Tighten ring compressor.Ensure posi-
tion of rings do not change during this opera-
tion.
(3) Position bearing onto connecting rod. Ensure
that hole in bearing shell aligns with hole in connect-
ing rod. Lubricate bearing surface with clean engine
oil.
Fig. 73 Identify Connecting Rod to Cylinder
PositionÐTypical
9 - 140 ENGINE - 4.7LDR
PISTON & CONNECTING ROD (Continued)
VIBRATION DAMPER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(3) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(4) Remove radiator upper hose.
(5) Remove upper fan shroud.
(6) Using Special Tools 6958 Spanner with Adapter
Pins 8346, loosen fan and viscous assembly from
water pump (Fig. 81).
(7) Remove fan and viscous assembly.
(8) Disconnect electrical connector for fan mounted
inside radiator shroud.
NOTE: Transmission cooler line snaps into shroud
lower right hand corner.
(9) Remove crankshaft damper bolt.
(10) Remove damper using Special Tools 8513
Insert and 1026 Three Jaw Puller (Fig. 82).
INSTALLATION
CAUTION: To prevent severe damage to the Crank-
shaft, Damper or Special Tool 8512±A, thoroughlyclean the damper bore and the crankshaft nose
before installing Damper.
(1) Align crankshaft damper slot with key in
crankshaft. Slide damper onto crankshaft slightly.
CAUTION: Special Tool 8512±A, is assembled in a
specific sequence. Failure to assemble this tool in
this sequence can result in tool failure and severe
damage to either the tool or the crankshaft.
(2) Assemble Special Tool 8512±A as follows, The
nut is threaded onto the shaft first. Then the roller
bearing is placed onto the threaded rod (The hard-
ened bearing surface of the bearingMUSTface the
nut). Then the hardened washer slides onto the
threaded rod (Fig. 83). Once assembled coat the
threaded rod's threads with MopartNickel Anti-
Seize or equivalent.
(3) Using Special Tool 8512±A, press damper onto
crankshaft (Fig. 84).
(4) Install then tighten crankshaft damper bolt to
175 N´m (130 ft. lbs.).
(5) Install fan blade assembly (Refer to 7 - COOL-
ING/ENGINE/FAN DRIVE VISCOUS CLUTCH -
INSTALLATION).
(6) Install radiator upper shroud and tighten fas-
teners to 11 N´m (95 in. lbs.).
(7) Connect electrical connector for shroud fan.
(8) Install radiator upper hose.
Fig. 81 FAN ASSEMBLY - REMOVAL/ASSEMBLY
1 - SPECIAL TOOL 6958 SPANNER WRENCH WITH ADAPTER
PINS 8346
2-FAN
Fig. 82 CRANKSHAFT DAMPER - REMOVAL
1 - SPECIAL TOOL 8513 INSERT
2 - SPECIAL TOOL 1026
9 - 144 ENGINE - 4.7LDR
(9) Install accessory drive belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(10) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(11) Connect negative cable to battery.
STRUCTURAL COVER
DESCRIPTION
The structural dust cover is made of die cast alu-
minum and joins the lower half of the transmission
bell housing to the engine bedplate.
OPERATION
The structural cover provides additional power-
train stiffness and reduces noise and vibration.
REMOVAL
(1) Raise vehicle on hoist.
(2) Remove the left hand exhaust pipe from
exhaust manifold.
(3) Loosen the right hand exhaust manifold-to-ex-
haust pipe retaining bolts.
(4) Remove the eight bolts retaining structural
cover (Fig. 85) in the sequence shown.
(5) Pivot the exhaust pipe downward and remove
the structural cover.
INSTALLATION
CAUTION: The structural cover must be installed as
described in the following steps. Failure to do so
will cause severe damage to the cover.
(1) Position the structural cover in the vehicle.
(2) Install all four bolts retaining the cover-to-en-
gine. DO NOT tighten the bolts at this time.
(3) Install the four cover-to-transmission bolts. Do
NOT tighten at this time.
Fig. 83 PROPER ASSEMBLY METHOD FOR
SPECIAL TOOL 8512±A
1 - BEARING
2 - NUT
3 - THREADED ROD
4 - BEARING HARDENED SURFACE (FACING NUT)
5 - HARDENED WASHER
Fig. 84 Crankshaft Damper Installation
1 - SPECIAL TOOL 8512
Fig. 85 Structural Cover
1 - BOLT
2 - BOLT
3 - BOLT
DRENGINE - 4.7L 9 - 145
VIBRATION DAMPER (Continued)
CAUTION: The structural cover must be held tightly
against both the engine and the transmission bell
housing during tightening sequence. Failure to do
so may cause damage to the cover.
(4) Starting with the two rear cover-to-engine
bolts, tighten bolts (1) (Fig. 86) to 54 N´m (40 ft. lbs.),
then tighten bolts (2) (Fig. 86) and (3) to 54 N´m ( 40
ft. lbs.) in the sequence shown.
(5) Install the exhaust pipe on left hand exhaust
manifold.
(6) Tighten exhaust manifold-to-exhaust pipe
retaining bolts to 20±26 N´m (15±20 ft. lbs.).
FRONT MOUNT
REMOVAL
2WD
(1) Disconnect the negative cable from the battery.
CAUTION: Remove the viscous fan before raising
engine. Failure to do so may cause damage to the
fan blade, fan clutch and fan shroud.(2) Remove the viscous fan (Refer to 7 - COOL-
ING/ENGINE/FAN DRIVE VISCOUS CLUTCH -
REMOVAL).
(3) Raise the vehicle.
(4) Remove the engine oil filter.
(5) Remove the oil drain trough.
(6) Support the engine with a suitable jack and a
block of wood across the full width of the engine oil
pan.
(7) Support the front axle with a suitable jack.
(8) Remove the (4) bolts that attach the engine
mounts to the front axle.
(9) Remove the (3) bolts that attach the front axle
to the left engine bracket.
(10) Lower the front axle.
(11) Remove the through bolts
(12) Raise the engine far enough to be able to
remove the left and right engine mounts.
(13) Remove the (8) mount to engine attaching
bolts
(14) Remove the engine mounts.
4WD
(1) Disconnect the negative cable from the battery.
(2) Remove the viscous fan.
(3) Raise the vehicle.
(4) Remove the skid plate.
(5) Remove the front crossmember.
(6) Remove the engine oil filter.
(7) Remove the oil drain trough.
(8) Support the engine with a suitable jack and a
block of wood across the full width of the engine oil
pan.
(9) Support the front axle with a suitable jack.
(10) Remove the (4) bolts that attach the engine
mounts to the front axle (Fig. 87).
(11) Remove the (3) bolts that attach the front axle
to the left engine bracket.
(12) Lower the front axle.
(13) Remove the (6) through bolts
Fig. 86 Structural Cover
1 - BOLT
2 - BOLT
3 - BOLT
9 - 146 ENGINE - 4.7LDR
STRUCTURAL COVER (Continued)
(7) Lower the vehicle.
(8) Install the viscous fan (Refer to 7 - COOLING/
ENGINE/FAN DRIVE VISCOUS CLUTCH -
REMOVAL).
(9) Reconnect the negative battery cable.
4WD
NOTE: For mount to engine block and left engine
bracket to front axle bolts, apply MoparTLock and
Seal Adhesive, Medium Strength Threadlocker.
(1) Install the right and left side engine mounts to
the front axle. Torque nuts to 94 N´m (70 ft. lbs.).
(2) Raise the front axle into the frame and install
the left and right side through bolts. Torque nuts to
94 N´m (70 ft. lbs.).
(3) Insert the two upper through bolts into the
right and left side engine mounts and loose assemble
the two nuts onto the through bolts.
(4) Lower the engine until the left and right side
engine brackets rest on the through bolts, and the
lower engine bracket through holes align with the
engine mounts, and the left engine bracket holes
align with the front axle slots (Fig. 90).
(5) Loose assemble the (3) bolts that attach the
front axle to the left engine bracket.
(6) Loose assemble the lower through bolts.
Fig. 89 ENGINE MOUNT SUPPORT BRACKET
1 - BOLT
2 - ENGINE MOUNT SUPPORT BRACKET
3 - BOLT
Fig. 90 ENGINE INSULATOR MOUNTS 4X4
1 - RH INSULATOR TO AXLE BOLT
2 - NUT
3 - PINION SUPPORT MOUNT
4 - LH INSULATOR MOUNT5 - LH INSULATOR TO AXLE BOLT
6 - FRONT AXLE
7 - NUT
8 - RH INSULATOR MOUNT
9 - 148 ENGINE - 4.7LDR
FRONT MOUNT (Continued)
(7) Torque the nuts for the (4) through bolts to 101
N´m (75 ft. lbs.).
(8) Torque the (3) bolts that attach the front axle
to the left engine bracket to 101 N´m (75 ft. lbs.).
(9) Install the oil drain trough.
(10) Install the engine oil filter.
(11) Install the front crossmember.
(12) Install the skid plate.
(13) Lower the vehicle.
(14) Install the viscous fan (Refer to 7 - COOL-
ING/ENGINE/FAN DRIVE VISCOUS CLUTCH -
REMOVAL).
(15) Reconnect the negative battery cable.
REAR MOUNT
REMOVAL
(1) Raise the vehicle on a hoist.
(2) Using a suitable jack, support transmission.
(3) Remove the nuts from the transmission mount
(Fig. 91).
(4) Remove the two bolts that attach the transmis-
sion mount to the engine bracket.
(5) Raise the transmission enough to remove the
mount from the crossmember.
(6) Remove the mount.
INSTALLATION
NOTE: Threadlocking compound must be applied to
the bolts before installation.
(1) Install the two bolts that attach the transmis-
sion mount to the transmission bracket.
(2) Torque the bolts to 61N´m (45 ft.lbs.) torque.(3) Lower the transmission so the transmission
mount rests on the crossmember, and the studs of
the transmission mount are aligned in the slots in
the crossmember.
(4) Install the nuts onto the transmission mount
studs through the crossmember access slot.
(5) Torque the nuts to 54N´m (40 ft. lbs.).
Fig. 91 TRANSMISSION MOUNT
1 - MOUNT
2 - CROSSMEMBER
3 - NUT
4 - BOLT
DRENGINE - 4.7L 9 - 149
FRONT MOUNT (Continued)
OIL LEVEL INDICATOR (DIPSTICK)
The engine oil level indicator is located at the right
rear of the engine on the 3.7L engines. (Fig. 96).
CRANKCASE OIL LEVEL INSPECTION
CAUTION: Do not overfill crankcase with engine oil,
pressure loss or oil foaming can result.
Inspect engine oil level approximately every 800
kilometers (500 miles). Unless the engine has exhib-
ited loss of oil pressure, run the engine for about five
minutes before checking oil level. Checking engine oil
level on a cold engine is not accurate.
To ensure proper lubrication of an engine, the
engine oil must be maintained at an acceptable level.
The acceptable levels are indicated between the ADD
and SAFE marks on the engine oil dipstick.
(1) Position vehicle on level surface.
(2) With engine OFF, allow approximately ten min-
utes for oil to settle to bottom of crankcase, remove
engine oil dipstick.
(3) Wipe dipstick clean.
(4)
Install 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 ADD mark on
dipstick.
ENGINE OIL CHANGE
Change engine oil at mileage and time intervals
described in Maintenance Schedules.Run engine until achieving normal operating tem-
perature.
(1) Position the vehicle on a level surface and turn
engine off.
(2) Hoist and support vehicle on safety stands.
(3) Remove oil fill cap.
(4)
Place a suitable drain pan under crankcase drain.
(5)Remove drain plug from crankcase and allow oil
to drain into pan. Inspect drain plug threads for stretch-
ing or other damage. Replace drain plug if damaged.
(6) Install drain plug in crankcase.
(7)
Lower vehicle and fill crankcase with specified
type and amount of engine oil described in this section.
(8) Install oil fill cap.
(9) Start engine and inspect for leaks.
(10) Stop engine and inspect oil level.
USED ENGINE OIL DISPOSAL
Care should be exercised when disposing used engine
oil after it has been drained from a vehicle engine.
Refer to the WARNING at beginning of this section.
OIL FILTER
REMOVAL
All engines are equipped with a high quality full-flow,
disposable type oil filter. DaimlerChrysler Corporation
recommends a Mopartor equivalent oil filter be used.
(1) Position a drain pan under the oil filter.
(2) Using a suitable oil filter wrench loosen filter.
(3) Rotate the oil filter counterclockwise (Fig. 97)to
remove it from the cylinder block oil filter boss.
Fig. 96 ENGINE OIL DIPSTICK 3.7L ENGINE
1 - TRANSMISSION DIPSTICK
2 - ENGINE OIL DIPSTICK
3 - ENGINE OIL FILL CAP
Fig. 97 Oil Filter - 4.7L Engine
1 - ENGINE OIL FILTER
9 - 154 ENGINE - 4.7LDR
OIL (Continued)