DODGE RAM 2003 Service Repair Manual

(7) Install the bedplate retaining bolts, making
sure to place the stud bolts in the correct location,
Torque the bolts in the sequence shown (Fig. 35).
²Hand tighten bolts1D,1G and 1Funtil the bed-
plate contacts the block.
²Tighten bolts1A±1Jto 54 N´m (40 ft. lbs.)
²Tighten bolts1±8to 7 N´m (5 ft. lbs.)
²Turn bolts1±8an additional 90É.
²Tighten boltsA±E27 N´m ( 20 ft. lbs.).
(8) Measure crankshaft end play.(9) Install the connecting rods and measure side
clearance(Refer to 9 - ENGINE/ENGINE BLOCK/
PISTON & CONNECTING ROD - STANDARD PRO-
CEDURE).
(10) Install oil pump(Refer to 9 - ENGINE/LUBRI-
CATION/OIL PUMP - INSTALLATION).
(11) Install the engine(Refer to 9 - ENGINE -
INSTALLATION).
Fig. 35 BEDPLATE TIGHTENING SEQUENCE
9 - 42 ENGINE - 3.7LDR
CRANKSHAFT (Continued)

CRANKSHAFT MAIN
BEARINGS
STANDARD PROCEDURE
MAIN BEARING FITTING
SELECT FIT IDENTIFICATION
The main bearings are ªselect fitº to achieve proper
oil clearances. For main bearing selection, the crank-
shaft position sensor target wheel has grade identifi-
cation marks stamped into it (Fig. 36). These marks
are read from left to right, corresponding with jour-
nal number 1, 2, 3, 4. The crankshaft position sensor
target wheel is mounted to the number 6 counter
weight on the crankshaft.
INSPECTION
Wipe the inserts clean and inspect for abnormal
wear patterns and for metal or other foreign material
imbedded in the lining. Normal main bearing insert
wear patterns are illustrated.
Inspect the back of the inserts for fractures, scrap-
ings or irregular wear patterns.
Inspect the upper insert locking tabs for damage.
Replace all damaged or worn bearing inserts.
MAIN BEARING JOURNAL DIAMETER
(CRANKSHAFT REMOVED)
Remove the crankshaft from the cylinder block(Re-
fer to 9 - ENGINE/ENGINE BLOCK/CRANKSHAFT
- REMOVAL).
Clean the oil off the main bearing journal.
Determine the maximum diameter of the journal
with a micrometer. Measure at two locations 90É
apart at each end of the journal.
The maximum allowable taper is 0.008mm (0.0004
inch.) and maximum out of round is 0.005mm (0.002
inch). Compare the measured diameter with the jour-
nal diameter specification (Main Bearing Fitting
Chart). Select inserts required to obtain the specified
bearing-to-journal clearance.
Install the crankshaft into the cylinder block(Refer
to 9 - ENGINE/ENGINE BLOCK/CRANKSHAFT -
INSPECTION).
Check crankshaft end play.
CRANKSHAFT MAIN BEARING SELECTION
(1) Service main bearings are available in four
grades. The chart below identifies the four service
grades available.
Crankshaft JOURNAL SIZE
SIZE mm (in.)
MARKING
9R9Size 63.488 - 63.496 mm
(2.4995 - 2.4998 in.)
9S9Size 63.496 - 63.500 mm (2.4998 - 2.4999
in.)
9T9Size 63.500 - 63.504 mm (2.4999 - 2.501
in.)
9U9Size 63.504 - 63.512 mm (2.5001 - 2.5004
in.)
Bearing size
Bearing
CodeSize Application
Upper Bearing
A.2.443 - 2.447
mmUse with crankshaft
size9R9
(.0961 - .0963
in.)
B2.439 - 2.443
mmUse with crankshaft
9S, T9
(0.960 -.o961
in.)
C2.435 - 2.439
mmUse with crankshaft
9U9
Fig. 36 MARKINGS ON TARGET WHEEL
1 - REARMOST CRANKSHAFT COUNTER WEIGHT
2 - TARGET WHEEL
3 - MAIN BEARING SELECT FIT MARKINGS
DRENGINE - 3.7L 9 - 43

Crankshaft JOURNAL SIZE
SIZE mm (in.)
MARKING
(.0958 - .0960
in.)
Lower Bearing Main919and949
9192.441 - 2.447
mmUse with crankshaft
9R, S9
(.0961 -.0963
in.)
9292.435 - 2.441
mmUse with crankshaft
9T, U9
(.0958 - .0962
in.)
Lower Main Bearing929and939
9392.429 - 2.435
mmUse with crankshaft
9R, S9
(.0956 - .0958
in.)
9492.423 - 2.429
mmUse with crankshaft
9T, U9
(.0953 - .0956
in.)
Bearing Clearances
Main91, 49
Crankshaft
9R9.004 - .034 mm ( .00015 - .0013 in.)
Crankshaft
9S9.004 - .030 mm ( .00015 - .0011 in.)
Crankshaft
9T9.006 - .032 mm (.0002 - .0012 in.)
Crankshaft
9U9.002 - .032 mm (.00007 -. 0012 in.)
Main92, 39
Crankshaft
9R9.016 - .046 mm (.0006 - .0018 in.)
Crankshaft
9S9.016 - .042 mm (.00062 - .016 in.)
Crankshaft
9T9.018 - .044 mm (.0007 - .0017 in.)
Crankshaft
9U9.014 - .044 mm (.0005 - .0017 in.)CRANKSHAFT OIL SEAL -
FRONT
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(3) Remove A/C compressor mouning fasteners and
set aside.
(4) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(5) Remove upper radiator hose.
(6) Disconnect electrical connector for fan mounted
inside radiator shroud.
(7) Remove radiator shroud attaching fasteners.
NOTE: Transmission cooler line snaps into shroud
lower right hand corner.
(8) Remove radiator cooling fan and shroud (Refer
to 7 - COOLING/ENGINE/RADIATOR FAN -
REMOVAL).
(9) Remove crankshaft damper bolt.
(10) Remove damper using Special Tools 8513
Insert and 1026 Three Jaw Puller (Fig. 37).
Fig. 37 Crankshaft Damper Removal
1 - SPECIAL TOOL 8513 INSERT
2 - SPECIAL TOOL 1026
9 - 44 ENGINE - 3.7LDR
CRANKSHAFT MAIN BEARINGS (Continued)

(11) Using Special Tool 8511, remove crankshaft
front seal (Fig. 38).
INSTALLATION
CAUTION: To prevent severe damage to the Crank-
shaft, Damper or Special Tool 8512, thoroughly
clean the damper bore and the crankshaft nose
before installing Damper.
(1) Using Special Tool 8348 and 8512, install
crankshaft front seal (Fig. 39).
(2) Install vibration damper (Refer to 9 - ENGINE/
ENGINE BLOCK/VIBRATION DAMPER - INSTAL-
LATION).
(3) Install radiator cooling fan and shroud (Refer
to 7 - COOLING/ENGINE/RADIATOR FAN -
INSTALLATION).
(4) Install upper radiator hose.
(5) Install A/C compressor and tighten fasteners to
54 N´m (40 ft. lbs.).
(6) Install accessory drive belt refer (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(7) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(8) Connect negative cable to battery.
CRANKSHAFT OIL SEAL -
REAR
REMOVAL
NOTE: This procedure can be performed in vehicle.
(1) If being preformed in vehicle, remove the
transmission.
(2) Remove the flexplate (Refer to 9 - ENGINE/
ENGINE BLOCK/FLEX PLATE - REMOVAL).
NOTE: The crankshaft oil seal CAN NOT be reused
after removal.
NOTE: The crankshaft rear oil seal remover Special
Tool 8506 must be installed deeply into the seal.
Continue to tighten the removal tool into the seal
until the tool can not be turned farther. Failure to
install tool correctly the first time will cause tool to
pull free of seal without removing seal from engine.
Fig. 38 Crankshaft Front Seal Removal
1 - SPECIAL TOOL 8511
Fig. 39 Crankshaft Front Seal Installation
1 - TIMING CHAIN COVER
2 - SPECIAL TOOL 8348
3 - SPECIAL TOOL 8512
DRENGINE - 3.7L 9 - 45
CRANKSHAFT OIL SEAL - FRONT (Continued)

(3) Using Special Tool 8506 (Fig. 40), remove the
crankshaft rear oil seal.
INSTALLATION
(1) Lubricate the crankshaft flange with engine oil.
(2) Position the magnetic seal guide Special Tool
8349±2 (Fig. 41) onto the crankshaft rear face. Then
position the crankshaft rear oil seal onto the guide.(3) Using Special Tools 8349 Crankshaft Rear Oil
Seal Installer and C-4171 Driver Handle (Fig. 42),
with a hammer, tap the seal into place. Continue to
tap on the driver handle until the seal installer seats
against the cylinder block crankshaft bore.
(4) Install the flexplate.
(5) Install the transmission.
Fig. 40 Crankshaft Rear Oil Seal Removal
1 - REAR CRANKSHAFT SEAL
2 - SPECIAL TOOL 8506
Fig. 41 Crankshaft Rear Oil Seal Guide Special Tool
8349±2 and Oil
1 - REAR CRANKSHAFT SEAL
2 - SPECIAL TOOL 8349±2 GUIDE
Fig. 42 Crankshaft Rear Oil Seal Installation
1 - REAR CRANKSHAFT SEAL
2 - SPECIAL TOOL 8349±1 INSTALLER
3 - SPECIAL TOOL C-4171 HANDLE
9 - 46 ENGINE - 3.7LDR
CRANKSHAFT OIL SEAL - REAR (Continued)

FLEX PLATE
REMOVAL
(1) Remove the transmission.
(2) Remove the bolts and flexplate.
INSTALLATION
(1) Position the flexplate onto the crankshaft and
install the bolts hand tight.
(2) Tighten the flexplate retaining bolts to 95 N´m
(70 ft. lbs.) in the sequence shown (Fig. 43).
(3) Install the transmission.
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 connecting rods are made of forged pow-
dered metal, with a ªfractured capº design. A full
floating piston pin is used to attach the piston to the
connecting rod (Fig. 44).
1 - CONNECTING ROD
2 - PISTON
3 - PISTON PIN
4 - OIL SLINGER SLOT
Fig. 43 Flexplate Tightening Sequence
1 - FLEXPLATE
Fig. 44 PISTON AND ROD ASSEMBLY
DRENGINE - 3.7L 9 - 47

STANDARD PROCEDURE
CONNECTING ROD BEARING FITTING
Inspect the connecting rod bearings for scoring.
Check the bearings for normal wear patterns, scor-
ing, grooving, fatigue and pitting (Fig. 45). Replace
any bearing that shows abnormal wear.
Inspect the connecting rod journals for signs of
scoring, nicks and burrs (Fig. 46).
Misaligned or bent connecting rods can cause
abnormal wear on pistons, piston rings, cylinder
walls, connecting rod bearings and crankshaft con-
necting rod journals. If wear patterns or damage to
any of these components indicate the probability of a
misaligned connecting rod, inspect it for correct rod
alignment. Replace misaligned, bent or twisted con-
necting rods.
(1) Wipe the oil from the connecting rod journal.
(2) Lubricate the upper bearing insert and position
in connecting rod. Center bearing insert in connect-
ing rod (Fig. 47)
(3) Use piston ring compressor and Guide Pins
Special Tool 8507 (Fig. 48) to install the rod and pis-
ton assemblies. The oil slinger slots in the rods must
face front of the engine. The ªFº's near the piston
wrist pin bore should point to the front of the engine.
(4) Install the lower bearing insert in the bearing
cap. Center bearing insert in connecting rod (Fig. 47).The lower insert must be dry. Place strip of Plasti-
gage across full width of the lower insert at the cen-
ter of bearing cap. Plastigage must not crumble in
use. If brittle, obtain fresh stock.
Fig. 45 Connecting Rod Bearing Inspection
1 - UPPER BEARING HALF
2 - MATING EDGES
3 - GROOVES CAUSED BY ROD BOLTS SCRATCHING JOURNAL
DURING INSTALLATION
4 - WEAR PATTERN - ALWAYS GREATER ON UPPER BEARING
Fig. 46 Scoring Caused by Insufficient Lubrication
or Damaged Crankshaft Journal
Fig. 47 Bearing Insert Location
1 - Connecting Rod
2 - Bearing Insert
- A, B less then .50 mm (.0196 in.)
9 - 48 ENGINE - 3.7LDR
PISTON & CONNECTING ROD (Continued)

(5) Install bearing cap and connecting rod on the
journal and tighten bolts to 27 N´m (20 ft. lbs.) plus a
90É turn. DO NOT rotate crankshaft. Plastigage will
smear, resulting in inaccurate indication.
(6) Remove the bearing cap and determine amount
of bearing-to-journal clearance by measuring the
width of compressed Plastigage (Fig. 49). Refer to
Engine Specifications for the proper clearance.Plas-
tigage should indicate the same clearance
across the entire width of the insert. If the
clearance varies, it may be caused by either a
tapered journal, bent connecting rod or foreign
material trapped between the insert and cap or
rod.
(7) If the correct clearance is indicated, replace-
ment of the bearing inserts is not necessary. Remove
the Plastigage from crankshaft journal and bearing
insert. Proceed with installation.
(8) If bearing-to-journal clearance exceeds the
specification, determin which services bearing set to
use the bearing sizes are as follows:
Bearing
MarkSIZE USED WITH
JOURNAL SIZE
.025 US.025 mm 57.883-57.867 mm
(.001 in.) (2.2788-2.2783 in.)
Std.STANDARD 57.908-57.892 mm
(2.2798-2.2792 in.)
.250 US.250 mm 57.658-57.646 mm
(.010 in.) (2.2700-2.2695 in.)
CAUTION: Connecting Rod Bolts are Torque to
Yield Bolts and Must Not Be Reused. Always
replace the Rod Bolts whenever they are loosened
or removed.
(9) Repeat the Plastigage measurement to verify
your bearing selection prior to final assembly.
(10) Once you have selected the proper insert,
install the insert and cap. Tighten the connecting rod
bolts to 27 N´m (20 ft. lbs.) plus a 90É turn.Fig. 48 Piston and Connecting Rod -Installation -
Typical
1 - ªFº TOWARD FRONT OF ENGINE
2 - OIL SLINGER SLOT
3 - RING COMPRESSOR
4 - SPECIAL TOOL 8507
Fig. 49 Measuring Bearing Clearance with
Plastigage
1 - PLASTIGAGE SCALE
2 - COMPRESSED PLASTIGAGE
DRENGINE - 3.7L 9 - 49
PISTON & CONNECTING ROD (Continued)

Slide snug-fitting feeler gauge between the con-
necting rod and crankshaft journal flange (Fig. 50).
Refer to Engine Specifications for the proper clear-
ance. Replace the connecting rod if the side clearance
is not within specification.
STANDARD PROCEDUREÐPISTON 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. 52).
(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 out-
side diameter of a coated piston will not provide accu-
rate results (Fig. 51). Therefore measuring the inside
diameter of the cylinder bore with a dial Bore Gauge is
MANDATORY
. To correctly select the proper size pis-
ton, 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).
Fig. 50 Checking Connecting Rod Side Clearance -
Typical
Fig. 51 DO NOT MEASURE MOLY COATED PISTON
1 - MOLY COATED
2 - MOLY COATED
Fig. 52 BORE GAUGE -TYPICAL
1 - FRONT
2 - BORE GAUGE
3 - CYLINDER BORE
4 - 38 MM (1.5 in)
9 - 50 ENGINE - 3.7LDR
PISTON & CONNECTING ROD (Continued)

(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 pistons
covered during this operation.
Pistons and connect-
ing rods must be removed from top of cylinder block.
When removing piston and connecting rod assemblies
from the engine, rotate crankshaft so the each con-
necting 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.
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.
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 bending.
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 position
of rings do not change during this operation.
(3)Position bearing onto connecting rod. Ensure that
hole in bearing shell aligns with hole in connecting rod.
Lubricate bearing surface with clean engine oil.
(4) Install Special Tool 8507 Connecting Rod
Guides into connecting rod bolt threads (Fig. 53).
Fig. 53 PISTON AND CONNECTING ROD
INSTALLATION
1 - ªFº TOWARD FRONT OF ENGINE
2 - OIL SLINGER SLOT
3 - RING COMPRESSOR
4 - SPECIAL TOOL 8507
DRENGINE - 3.7L 9 - 51
PISTON & CONNECTING ROD (Continued)