Engine Installation DODGE RAM 1500 1998 2.G Workshop Manual

(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.
(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 atapered 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.
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
9 - 50 ENGINE - 3.7LDR
PISTON & CONNECTING ROD (Continued)

(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.
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 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. 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 outside diameter of a coated piston will not pro-
vide accurate results (Fig. 51). 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).
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)
DRENGINE - 3.7L 9 - 51
PISTON & CONNECTING ROD (Continued)

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-
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.
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 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.
(4) Install Special Tool 8507 Connecting Rod
Guides into connecting rod bolt threads (Fig. 53).
(5) The pistons are marked on the piston pin bore
surface with an raised ªFº indicating installation
position. This mark must be pointing toward the
front of engine on both cylinder banks. The connect-
ing rod oil slinger slot faces the front of the engine
(Fig. 54).
(6) Wipe cylinder bore clean and lubricate with
engine oil.
(7) Rotate crankshaft until connecting rod journal
is on the center of cylinder bore. Insert rod and pis-
ton into cylinder bore and carefully position connect-
ing rod guides over crankshaft journal.
(8) Tap piston down in cylinder bore using a ham-
mer handle. While at the same time, guide connect-
ing rod into position on rod journal.
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) Lubricate rod bolts and bearing surfaces with
engine oil. Install connecting rod cap and bearing.
Tighten bolts to 27 N´m (20 ft. lbs.) plus 90É.
(10) Install the following components:
²Cylinder head(s). (Refer to 9 - ENGINE/CYLIN-
DER HEAD - INSTALLATION).
9 - 52 ENGINE - 3.7LDR
PISTON & CONNECTING ROD (Continued)

²Timing chain and cover. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT / CHAIN COVER(S)
- INSTALLATION).
²Cylinder head covers (Refer to 9 - ENGINE/
CYLINDER HEAD/CYLINDER HEAD COVER(S) -
INSTALLATION).
²Oil pan and gasket/windage tray. (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
(11) Fill crankcase with proper engine oil to cor-
rect level.
(12) Connect negative cable to battery.
PISTON RINGS
STANDARD PROCEDURE - PISTON RING
FITTING
Before reinstalling used rings or installing new
rings, the ring clearances must be checked.
(1) Wipe the cylinder bore clean.
(2) Insert the ring in the cylinder bore.NOTE: The ring gap measurement must be made
with the ring positioned at least 12mm (0.50 inch.)
from bottom of cylinder bore.
(3) Using a piston, to ensure that the ring is
squared in the cylinder bore, slide the ring downward
into the cylinder.
(4) Using a feeler gauge check the ring end gap
(Fig. 55). Replace any rings not within specification.
Fig. 53 PISTON AND CONNECTING ROD
INSTALLATION
1 - ªFº TOWARD FRONT OF ENGINE
2 - OIL SLINGER SLOT
3 - RING COMPRESSOR
4 - SPECIAL TOOL 8507
Fig. 54 PISTON AND CONNECTING ROD
ORIENTATION
1 - MAJOR THRUST SIDE OF PISTON
2 - OIL SLINGER SLOT
Fig. 55 Ring End Gap Measurement - Typical
1 - FEELER GAUGE
DRENGINE - 3.7L 9 - 53
PISTON & CONNECTING ROD (Continued)

(8) Install the oil ring expander.
(9) Install upper side rail (Fig. 57) by placing one
end between the piston ring groove and the expander
ring. Hold end firmly and press down the portion to
be installed until side rail is in position. Repeat this
step for the lower side rail.
(10) Install No. 2 intermediate piston ring using a
piston ring installer (Fig. 58).
(11) Install No. 1 upper piston ring using a piston
ring installer (Fig. 58).
(12) Position piston ring end gaps as shown in
(Fig. 59). It is important that expander ring gap is at
least 45É from the side rail gaps, but not on the pis-
ton pin center or on the thrust direction.
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. 60).
(7) Remove fan and viscous assembly.
Fig. 57 Side Rail - Installation
1 - SIDE RAIL END
Fig. 58 Upper and Intermediate Rings - Installation
Fig. 59 Piston Ring End Gap Position
1 - SIDE RAIL UPPER
2 - NO. 1 RING GAP
3 - PISTON PIN
4 - SIDE RAIL LOWER
5 - NO. 2 RING GAP AND SPACER EXPANDER GAP
Fig. 60 FAN ASSEMBLY - REMOVAL/ASSEMBLY
1 - SPECIAL TOOL 6958 SPANNER WRENCH WITH ADAPTER
PINS 8346
2-FAN
DRENGINE - 3.7L 9 - 55
PISTON RINGS (Continued)

(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. 61).
INSTALLATION
CAUTION: To prevent severe damage to the Crank-
shaft, Damper or Special Tool 8512±A, thoroughly
clean 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. 62). Once assembled coat thethreaded rod's threads with MopartNickel Anti-
Seize or equivalent.
(3) Using Special Tool 8512±A, press damper onto
crankshaft (Fig. 63).
(4) Install then tighten crankshaft damper bolt to
175 N´m (130 ft. lbs.).
Fig. 61 CRANKSHAFT DAMPER - REMOVAL
1 - SPECIAL TOOL 8513 INSERT
2 - SPECIAL TOOL 1026
Fig. 62 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. 63 Crankshaft Damper Installation
1 - SPECIAL TOOL 8512
9 - 56 ENGINE - 3.7LDR
VIBRATION DAMPER (Continued)

(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.
(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. 64) 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.
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. 65) to 54 N´m (40 ft. lbs.),
then tighten bolts (2) (Fig. 65) 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.).
Fig. 64 Structural Cover
1 - BOLT
2 - BOLT
3 - BOLT
Fig. 65 Structural Cover
1 - BOLT
2 - BOLT
3 - BOLT
DRENGINE - 3.7L 9 - 57
VIBRATION DAMPER (Continued)

(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
(14) Raise the engine far enough to be able to
remove the left (Fig. 67) and right (Fig. 68) engine
mounts.
(15) Remove the engine mounts.
INSTALLATION
2WD
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 engine block with (8) bolts. Torque bolts to 54
N´m (40 ft. lbs.).
(2) Insert the (2) through bolts into the right and
left side engine mounts and loose assemble the two
nuts onto the through bolts.
(3) Lower the engine until the through bolts rest
onto the slots in the frame brackets.(4) Tighten the through bolt nuts to 94 N´m (70 ft.
lbs.).
(5) Install the oil drain trough.
(6) Install the engine oil filter.
(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. 69).
(5) Loose assemble the (3) bolts that attach the
front axle to the left engine bracket.
Fig. 67 ENGINE MOUNT SUPPORT BRACKET
1 - BOLT
2 - ENGINE MOUNT SUPPORT BRACKET
3 - BOLT
Fig. 68 ENGINE MOUNT SUPPORT BRACKET RH
1 - BOLT
2 - ENGINE MOUNT SUPPORT BRACKET
DRENGINE - 3.7L 9 - 59
FRONT MOUNT (Continued)

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. 70).
(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.).
LUBRICATION
DESCRIPTION
The lubrication system is a full flow filtration pres-
sure feed type.
OPERATION
Oil from the oil pan is pumped by a gerotor type oil
pump directly mounted to the crankshaft nose. Oil
pressure is controlled by a relief valve mounted
inside the oil pump housing. For lubrication flow
refer to (Fig. 71)
The camshaft exhaust valve lobes and rocker arms
are lubricated through a small hole in the rocker
arm; oil flows through the lash adjuster then through
the rocker arm and onto the camshaft lobe. Due to
the orientation of the rocker arm, the camshaft
intake lobes are not lubed in the same manner as the
exhaust lobes. The intake lobes are lubed through
internal passages in the camshaft. Oil flows through
a bore in the No. 3 camshaft bearing bore, and as the
camshaft turns, a hole in the camshaft aligns with
the hole in the camshaft bore allowing engine oil to
enter the camshaft tube. The oil then exits through
1.6mm (0.063 in.) holes drilled into the intake lobes,
lubricating the lobes and the rocker arms.
Fig. 70 TRANSMISSION MOUNT
1 - MOUNT
2 - CROSSMEMBER
3 - NUT
4 - BOLT
DRENGINE - 3.7L 9 - 61

OIL PAN
DESCRIPTION
The engine oil pan is made of laminated steel and
has a single plane sealing surface. The sandwich
style oil pan gasket has an integrated windage tray
and steel carrier (Fig. 73). The sealing area of the
gasket is molded with rubber and is designed to be
reused as long as the gasket is not cut, torn or
ripped.
REMOVAL
(1) Disconnect the negative battery cable.
(2) Install engine support fixture special tool #
8534.Do not raise engine at this time.
(3) Loosen both left and right side engine mount
through bolts. Do not remove bolts.
(4) Remove the structural dust cover, if equipped.
(5) Drain engine oil.
(6) Remove the front crossmember(Refer to 13 -
FRAME & BUMPERS/FRAME/FRONT CROSS-
MEMBER - REMOVAL).
CAUTION: Only raise the engine enough to provide
clearance for oil pan removal. Check for proper
clearance at fan shroud to fan and cowl to intake
manifold.
(7) Raise engine using special tool 8534 to provide
clearance to remove oil pan.
NOTE: Do not pry on oil pan or oil pan gasket. Gas-
ket is integral to engine windage tray and does not
come out with oil pan.
(8) Remove the oil pan mounting bolts and oil pan.
(9) Unbolt oil pump pickup tube and remove tube.
(10) Inspect the integral windage tray (Fig. 73)
and gasket and replace as needed.
CLEANING
(1) Clean oil pan in solvent and wipe dry with a
clean cloth.
(2) Clean the oil pan gasket surface.DO NOTuse
a grinder wheel or other abrasive tool to clean seal-
ing surface.
(3) Clean oil screen and tube thoroughly in clean
solvent.
INSPECTION
(1) Inspect oil drain plug and plug hole for
stripped or damaged threads. Repair as necessary.
(2) Inspect the oil pan mounting flange for bends
or distortion. Straighten flange, if necessary.
INSTALLATION
(1) Clean the oil pan gasket mating surface of the
bedplate and oil pan.
(2) Inspect integrated oil pan gasket, and replace
as necessary.
(3) Position the integrated oil pan gasket/windage
tray assembly.
(4) Install the oil pickup tube
(5) Install the mounting bolt and nuts. Tighten
nuts to 28 N´m (20 ft. lbs.).
(6) If removed, install stud at position No. 9. (Fig.
74).
(7) Position the oil pan and install the mounting
bolts and nut. Tighten the mounting bolts and nut to
15 N´m (11 ft. lbs.) in the sequence shown (Fig. 74).
(8) Lower the engine into mounts using special
tool 8534.
(9) Install both the left and right side engine
mount through bolts. Tighten the nuts to 68 N´m (50
ft. lbs.).
(10) Remove special tool 8534.
(11) Install structural dust cover, if equipped.
Fig. 73 Oil Pan And Gasket
1 - OIL PAN
2 - WINDAGE TRAY AND INTEGRATED OIL PAN GASKET
9 - 66 ENGINE - 3.7LDR