1998 DODGE RAM 1500 Cooling system

þ Loss of engine power
þ Engine misfiring
þ Poor fuel economy
²Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
þ Engine overheating
þ Loss of coolant
þ Excessive steam (white smoke) emitting from
exhaust
þ Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test in this
section. An engine cylinder head gasket leaking
between adjacent cylinders will result in approxi-
mately a 50±70% reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester's pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL
(1) Disconnect the battery negative cable.
(2) Drain cooling system.
(3) Remove the air cleaner resonator and duct
work.
(4) Remove the generator.
(5) Remove closed crankcase ventilation system.
(6) Disconnect the evaporation control system.
(7) Perform the Fuel System Pressure Release pro-
cedure (Refer to 14 - FUEL SYSTEM/FUEL DELIV-
ERY - STANDARD PROCEDURE). Disconnect the
fuel supply line (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY/QUICK CONNECT FITTING - STAN-
DARD PROCEDURE).
(8) Disconnect heater hoses.
(9) Remove cylinder head covers and gaskets.
(10) Remove intake manifold and throttle body as
an assembly.
(11) Remove rocker arm assemblies and push rods.
Identify to ensure installation in original locations.
(12) Remove the head bolts from each cylinder
head and remove cylinder heads. Discard the cylin-
der head gasket.
CLEANING
Clean all surfaces of cylinder block and cylinder
heads.
Clean cylinder block front and rear gasket surfaces
using a suitable solvent.
INSPECTION
(1) Inspect the cylinder head for out-of-flatness,
using a straightedge and a feeler gauge. If tolerances
exceed 0.0508 mm (0.002 in.) replace the cylinder
head.
(2) Inspect the valve seats for damage. Service the
valve seats as necessary.
(3) Inspect the valve guides for wear, cracks or
looseness. If either condition exist, replace the cylin-
der head.
(4) Inspect pushrods. Replace worn or bent push-
rods.
INSTALLATION
(1) Clean all surfaces of cylinder block and cylin-
der heads.
(2) Clean cylinder block front and rear gasket sur-
faces using a suitable solvent.
CAUTION: The head gaskets are not interchange-
able between left and right sides. They are marked
ªLº and ªRº to indicate left and right sides.
(3) Position new cylinder head gaskets onto the
cylinder block.
9 - 200 ENGINE - 5.7LDR
CYLINDER HEAD (Continued)

CAUTION: The head gaskets are marked ªTOPº to
indicate which side goes up.
(4) Position cylinder heads onto head gaskets and
cylinder block.
(5) Tighten the cylinder head bolts in three steps
(Fig. 4):
²Step 1Ð Snug tighten M12 cylinder head bolts,
in sequence, to 34 N´m (25 ft. lbs.) and M8 bolts to
20 N´m (15 ft. lbs.) torque.
²Step 2Ð Tighten M12 cylinder head bolts, in
sequence, to 54 N´m (40 ft. lbs.) and verify M8 bolts
to 20 N´m (15 ft. lbs.) torque..
²Step 3Ð Turn M12 cylinder head bolts, in
sequence, 90 degrees and tighten M8 bolts to 34 N´m
(25 ft. lbs.) torque.
(6) Install push rods and rocker arm assemblies in
their original position.
(7) Install the intake manifold and throttle body
assembly.
(8) If required, adjust spark plugs to specifications.
Install the plugs.
(9) Connect the heater hoses.
(10) Install the fuel supply line.
(11) Install the generator and drive belt.
(12) Install cylinder head covers(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(13) Connect the evaporation control system.
(14) Install the air cleaner.
(15) Fill cooling system.
(16) Connect the negative cable to the battery.
(17) Start engine check for leaks.CYLINDER HEAD COVER(S)
REMOVAL
(1) Disconnect battery negative cable.
(2) Disconnect coil on plug connectors.
CAUTION: The ground straps must be installed in
the same location as removed. The covers are
machined to accept the ground straps in those
locations only.
(3) Remove cylinder head cover retaining bolts,
and ground straps.
(4) Remove cylinder head cover.
NOTE: The gasket may be used again, provided no
cuts, tears, or deformation has occurred.
INSTALLATION
CAUTION: Do not use harsh cleaners to clean the
cylinder head covers. Severe damage to covers
may occur.
CAUTION: DO NOT allow other components includ-
ing the wire harness to rest on or against the
engine cylinder head cover. Prolonged contact with
other objects may wear a hole in the cylinder head
cover.
(1) Clean cylinder head cover and both sealing sur-
faces. Inspect and replace gasket as necessary.
(2)
Install cylinder head cover and hand start all fas-
teners. Verify that all double ended studs are in the cor-
rect location and install left and right ground straps.
CAUTION: The ground straps must be installed in
the same location as removed. The covers are
machined to accept the ground straps in those
locations only.
NOTE: The right hand ground strap is located on
the front inboard stud. The left hand ground strap
is located on the rear inboard stud.
(3) Tighten cylinder head cover bolts and double
ended studs to 8 N´m (70 in. lbs). Begin torque
sequence in the middle of head cover and torque
bolts moving outward in a crisscross pattern from top
to bottom.
(4) Install ignition coil on plug, and torque fasten-
ers to 12 N´m (105 in. lbs)
(5) Connect, ignition coil electrical connectors.
(6) Install PCV hose.
(7) Connect battery negative cable.
Fig. 4 CYLINDER HEAD TIGHTENING SEQUENCE
DRENGINE - 5.7L 9 - 201
CYLINDER HEAD (Continued)

shaft counterweight has grade identification marks
stamped into it. These marks are read from left to
right, corresponding with journal number 1, 2, 3, 4
and 5.
NOTE: Service main bearings are coded. These
codes identify what size (grade) the bearing is.
MAIN BEARING SELECTION CHART - 5.7L
GRADE SIZE mm
(in.)FOR USE WITH
MARKING JOURNAL SIZE
A0.008 mm
U/S64.988±64.995 mm
(0.0004 in.)
U/S(2.5585± 2.5588in.)
BNOMINAL 64.996±65.004 mm
(2.5588±2.5592 in.)
C0.008 mm
O/S65.005±65.012 mm
(0.0004 in.)
O/S(2.5592±2.5595 in.)
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 (Fig. 9).
NOTE: If any of the crankshaft journals are scored,
the crankshaft must be repaired or replaced.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.
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) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(4) Remove upper radiator hose.
(5) Remove radiator shroud attaching fasteners.
(6) Remove radiator cooling fan and shroud (Refer
to 7 - COOLING/ENGINE/RADIATOR FAN -
REMOVAL).
(7) Remove crankshaft damper bolt.
(8) Remove damper using Special Tools 8513A
Insert and 8454 Three Jaw Puller.
(9) Using Special Tool 9071, remove crankshaft
front seal.
INSTALLATION
CAUTION: The front crankshaft seal must be
installed dry. Do not apply lubricant to sealing lip or
to outer edge.
(1) Using Special Tool 8348 and 8512A, install
crankshaft front seal.
CAUTION: To prevent severe damage to the Crank-
shaft or Damper, thoroughly clean the damper bore
and the crankshaft nose before installing Damper.
(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 accessory drive belt refer (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(6) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(7) Connect negative cable to battery.
Fig. 9 Main Bearing Wear Patterns
1 - UPPER INSERT
2 - NO WEAR IN THIS AREA
3 - LOW AREA IN BEARING LINING
4 - LOWER INSERT
9 - 208 ENGINE - 5.7LDR
CRANKSHAFT MAIN BEARINGS (Continued)

(10) Install No. 2 intermediate piston ring using a
piston ring installer (Fig. 16).
(11) Install No. 1 upper piston ring using a piston
ring installer (Fig. 16).
(12) Position piston ring end gaps as shown in
(Fig. 17). 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.
(7) Remove fan and viscous assembly.
(8) Remove crankshaft damper bolt.
(9) Remove damper using Special Tools 8513A
Insert and 8454 Three Jaw Puller.
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) 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. 18). Once assembled coat the
threaded rod's threads with MopartNickel Anti-
Seize or (Loctite No. 771).
Fig. 16 UPPER AND INTERMEDIATE RINGS
Fig. 17 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. 18 Proper Assembly Method for Special Tool
8512
1 - BEARING
2 - NUT
3 - THREADED ROD
4 - BEARING HARDENED SURFACE (FACING NUT)
5 - HARDENED WASHER
DRENGINE - 5.7L 9 - 215
PISTON RINGS (Continued)

(3) Using Special Tool 8512±A, press damper onto
crankshaft.
(4) Install then tighten crankshaft damper bolt to
176 N´m (129 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) Install radiator upper hose.
(8) Install accessory drive belt (Refer to 7 - COOL-
ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL-
LATION).
(9) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(10) 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.
OPERATION
The structural cover provides additional power-
train stiffness and reduces noise and vibration.
REMOVAL
(1) Raise vehicle on hoist.
CAUTION: On manual transmission vehicles, the
7/16 inch engine block to clutch housing bolts must
be loosened before removal of the structural dust
cover. Clutch housing distortion will occur if this
procedure is not followed.
(2) Remove the bolts retaining structural cover.
(3) Remove the structural cover.
INSTALLATION
AUTOMATIC TRANSMISSION
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 bellhousing during tightening sequence. Failure to do
so may cause damage to the cover.
(4) Torque the (4)structural dust cover bolts that
go into the transmission to 6-11 N´m (50-100 in.lbs.).
(5) Torque the (4) structural dust cover bolts that
go into the engine block to 6-11 N´m (50-100 in.lbs.).
(6) Starting with the two rear cover-to-engine
bolts, tighten bolts (1) (Fig. 19) to 54 N´m (40 ft. lbs.),
then tighten bolts (2) (Fig. 19) and (3) to 54 N´m ( 40
ft. lbs.) in the sequence shown.
(7) Install the exhaust pipe on left hand exhaust
manifold.
(8) Tighten exhaust manifold-to-exhaust pipe
retaining bolts to 20±26 N´m (15±20 ft. lbs.).
MANUAL TRANSMISSION
CAUTION: The 7/16 inch engine block to clutch
housing bolts must be loosened before removal/in-
stallation of the structural dust cover. Clutch hous-
ing distortion will occur if this procedure is not
followed.
(1) Position the structural cover in the vehicle.
CAUTION: The structural cover must be installed as
described in the following steps. Failure to do so
will cause severe damage to the cover, and engine
noise.
(2) Install all bolts retaining the cover-to-engine.
DO NOT tighten the bolts at this time (Fig. 20).
(3) Install the cover-to-transmission bolts. Do NOT
tighten at this time.
Fig. 19 Structural Cover
1 - BOLT
2 - BOLT
3 - BOLT
9 - 216 ENGINE - 5.7LDR
VIBRATION DAMPER (Continued)

INSPECTION
Inspect manifold for cracks.
Inspect mating surfaces of manifold for flatness
with a straight edge. Gasket surfaces must be flat
within 0.2 mm per 300 mm (0.008 inch per foot).
INSTALLATION
EXHAUST MANIFOLD
(1) Install manifold gasket and manifold.
(2) Install manifold bolts and tighten to 25 N´m
(18 ft. lbs.).
(3) Install heat shield and tighten nuts to 15 N´m
(11 ft. lbs.).
(4) Lower engine.
CAUTION: Do not damage engine harness while
lowering the engine.
(5) Remove engine support fixture from engine.
(6) Raise vehicle.
(7) Tighten right and left side engine mount
through bolts.
(8) Install exhaust flange to pipe bolts.
(9) Lower vehicle.
(10) Connect negative battery cable.
TIMING/CHAIN COVER
REMOVAL
(1) Disconnect the battery negative cable.
(2) Remove air cleaner assembly.
(3) Drain cooling system.
(4) Remove accessory drive belt.
(5) Remove fan and fan drive assembly (Refer to 7
- COOLING/ENGINE/FAN DRIVE VISCOUS
CLUTCH - REMOVAL).
(6) Remove coolant bottle and washer bottle.
(7) Remove fan shroud.
NOTE: It is not necessary to disconnect A/C lines or
discharge freon.
(8) Remove A/C compressor and set aside.
(9) Remove the generator.
(10) Remove upper radiator hose.
(11) Disconnect both heater hoses at timing cover.
(12) Disconnect lower radiator hose at engine.
(13) Remove accessory drive belt tensioner and
both idler pulleys.
(14) Remove crankshaft damper(Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL).NOTE: Do not remove the hoses from the power
steering pump.
(15) Remove power steering pump and set aside.
(16) Remove the dipstick support bolt.
(17) Drain the engine oil.
(18) Remove the oil pan and pick up tube(Refer to
9 - ENGINE/LUBRICATION/OIL PAN - REMOVAL).
NOTE: It is not necessary to remove water pump for
timing cover removal.
(19) Remove timing cover bolts and remove cover.
INSTALLATION
(1) Clean timing chain cover and block surface.
NOTE: Always install a new gasket on timing cover.
(2) Install cover and new gasket. Tighten fasteners
to 28 N´m (250 in. lbs.).
NOTE: The large lifting stud is torqued to 55 N´m
(40 ft. lbs.).
(3) Install the oil pan and pick up tube(Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
(4) Install the A/C compressor.
(5) Install the generator.
(6) Install power steering pump.
(7) Install the dipstick support bolt.
(8) Install the thermostat housing.
(9) Install crankshaft damper(Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION).
(10) Install accessory drive belt tensioner assembly
and both idler pulleys.
(11) Install radiator lower hose.
(12) Install both heater hoses.
(13) Install radiator fan shroud.
(14) Install the fan and fan drive assembly
(15) Install the accessory drive belt.
(16) Install the coolant bottle and washer bottle.
(17) Install the upper radiator hose.
(18) Install the air cleaner assembly.
(19) Fill cooling system.
(20) Refill engine oil.
(21) Connect the battery negative cable.
DRENGINE - 5.7L 9 - 227
EXHAUST MANIFOLD (Continued)

TIMING/CHAIN AND
SPROCKETS
REMOVAL
(1) Disconnect battery negative cable.
(2) Drain cooling system.
(3) Remove Timing Chain Cover.
CAUTION: The camshaft pin and the slot in the cam
sprocket must be clocked at 12:00. The crankshaft
keyway must be clocked at 2:00. The crankshaft
sprocket must be installed so that the dots and or
paint marking is at 6:00.
(4) Re-install the vibration damper bolt finger
tight. Using a suitable socket and breaker bar, rotate
the crankshaft to align timing chain sprockets and
keyways as shown (Fig. 33).
(5) Retract tensioner shoe until hole in shoe lines
up with hole in bracket. Slide a suitable pin into the
holes.
(6) Remove camshaft sprocket attaching bolt and
remove timing chain with crankshaft and camshaft
sprockets.
(7) If tensioner assembly is to be replaced, remove
the tensioner to block bolts and remove tensioner
assembly.
INSTALLATION
(1) If tensioner assembly is being replaced, install
tensioner and mounting bolts. Torque bolts to 28 N´m
(250 in. lbs.).
(2) Retract tensioner if required.
CAUTION: The camshaft pin and the slot in the cam
sprocket must be clocked at 12:00. The crankshaft
keyway must be clocked at 2:00. The crankshaft
sprocket must be installed so that the dots and or
paint marking is at 6:00.
(3) Place both camshaft sprocket and crankshaft
sprocket on the bench with timing marks on exact
imaginary center line through both camshaft and
crankshaft bores (Fig. 34).
CAUTION: The timing chain must be installed with
the single plated link aligned with the dot and or
paint marking on the camshaft sprocket. The crank-
shaft sprocket is aligned with the dot and or paint
marking on the sprocket between two plated timing
chain links.
(4) Place timing chain around both sprockets (Fig.
34).
(5) Lift sprockets and chain (keep sprockets tight
against the chain in position as shown).
(6) Slide both sprockets evenly over their respec-
tive shafts and check alignment of timing marks.
Fig. 33 5.7L TIMING MARK ALIGNMENT
1 - Chain Tensioner
2 - Camshaft Sprocket
3 - Crankshaft Sprocket
Fig. 34 5.7L TIMING MARK ALIGNMENT
1 - Chain Tensioner
2 - Camshaft Sprocket
3 - Crankshaft Sprocket
9 - 228 ENGINE - 5.7LDR

(7) Install the camshaft bolt. Tighten the bolt to
122 N´m (90 ft. lbs.) torque.
(8)Remove tensioner pin.Again, verify align-
ment of timing marks.
(9) Install the oil pump(Refer to 9 - ENGINE/LU-
BRICATION/OIL PUMP - INSTALLATION).
(10) Install the oil pan and pick up(Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
(11) Install the timing chain cover(Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).
(12) Fill cooling system(Refer to 7 - COOLING -
STANDARD PROCEDURE).
(13) Connect battery negative cable.
(14) Start engine and check for oil and coolant
leaks.TIMING CHAIN/TENSIONER
DESCRIPTION
The timing chain tensioner is a stamped steel con-
stant tension mechanical design. It is mounted to the
front of the engine, behind the timing chain drive.
OPERATION
The timing chain tension is maintained by routing
the timing chain through the tensioner assembly. A
nylon covered spring steel arm presses on the timing
chain maintaining the correct chain tension.
DRENGINE - 5.7L 9 - 229
TIMING/CHAIN AND SPROCKETS (Continued)