1998 DODGE RAM 1500 Oil pan

ENGINE BLOCK
DESCRIPTION
The cylinder block is made of cast iron. The block
is a closed deck design with the left bank forward. To
provide high rigidity and improved NVH an
enhanced compacted graphite bedplate is bolted to
the block. The block design allows coolant flow
between the cylinders bores, and an internal coolant
bypass to a single poppet inlet thermostat is included
in the cast aluminum front cover.
STANDARD PROCEDURE - CYLINDER BORE
HONING
Before honing, stuff plenty of clean shop towels
under the bores and over the crankshaft to keep
abrasive materials from entering the crankshaft
area.
(1) Used carefully, the Cylinder Bore Sizing Hone
C-823, equipped with 220 grit stones, is the best tool
for this job. In addition to deglazing, it will reduce
taper and out-of-round, as well as removing light
scuffing, scoring and scratches. Usually, a few strokes
will clean up a bore and maintain the required lim-
its.
CAUTION: DO NOT use rigid type hones to remove
cylinder wall glaze.
(2) Deglazing of the cylinder walls may be done if
the cylinder bore is straight and round. Use a cylin-
der surfacing hone, Honing Tool C-3501, equipped
with 280 grit stones (C-3501-3810). about 20-60
strokes, depending on the bore condition, will be suf-
ficient to provide a satisfactory surface. Using honing
oil C-3501-3880, or a light honing oil, available from
major oil distributors.
CAUTION: DO NOT use engine or transmission oil,
mineral spirits, or kerosene.
(3) Honing should be done by moving the hone up
and down fast enough to get a crosshatch pattern.
The hone marks should INTERSECT at 50É to 60É
for proper seating of rings (Fig. 48).
(4) A controlled hone motor speed between 200 and
300 RPM is necessary to obtain the proper cross-
hatch angle. The number of up and down strokes per
minute can be regulated to get the desired 50É to 60É
angle. Faster up and down strokes increase the cross-
hatch angle.
(5) After honing, it is necessary that the block be
cleaned to remove all traces of abrasive. Use a brush
to wash parts with a solution of hot water and deter-
gent. Dry parts thoroughly. Use a clean, white, lint-free cloth to check that the bore is clean. Oil the
bores after cleaning to prevent rusting.
CLEANING
Thoroughly clean the oil pan and engine block gas-
ket surfaces.
Use compressed air to clean out:
²The galley at the oil filter adaptor hole.
²The front and rear oil galley holes.
²The feed holes for the crankshaft main bearings.
Once the block has been completely cleaned, apply
Loctite PST pipe sealant with Teflon 592 to the
threads of the front and rear oil galley plugs. Tighten
the 1/4 inch NPT plugs to 20 N´m (177 in. lbs.)
torque. Tighten the 3/8 inch NPT plugs to 27 N´m
(240 in. lbs.) torque.
INSPECTION
(1) It is mandatory to use a dial bore gauge to
measure each cylinder bore diameter. To correctly
select the proper size piston, a cylinder bore gauge,
capable of reading in 0.003 mm (.0001 in.) INCRE-
MENTS is required. If a bore gauge is not available,
do not use an inside micrometer (Fig. 49).
(2) Measure the inside diameter of the cylinder
bore at three levels below top of bore. Start perpen-
dicular (across or at 90 degrees) to the axis of the
crankshaft and then take two additional reading.
(3) Measure the cylinder bore diameter crosswise
to the cylinder block near the top of the bore. Repeat
Fig. 48 CYLINDER BORE CROSSHATCH PATTERN
1 - CROSSHATCH PATTERN
2 - INTERSECT ANGLE
9 - 128 ENGINE - 4.7LDR

CORE PLUGS
REMOVAL
(1) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(2) Using a blunt tool such as a drift or a screw
driver and a hammer, strike the bottom edge of the
cup plug (Fig. 55)
(3) Using a suitable pair of pliers, grasp the core
plug and remove.
INSTALLATION
NOTE: Thoroughly clean core plug bore, remove all
of the old sealer.
(1) Coat the edges of the engine core plug and the
core plug bore with Mopar Gasket Maker, or equiva-
lent.
NOTE: It is not necessary to wait for the sealant to
cure on the core plugs. The cooling system can be
filled and the vehicle returned to service immedi-
ately.
(2) Using proper plug driver, drive core plug into
the core plug bore. The sharp edge of the core plug
should be at least 0.50 mm (0.020 in.) inside the lead
in chamfer.
(3) Refill the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
CRANKSHAFT
DESCRIPTION
The crankshaft is constructed of nodular cast iron.
The crankshaft is a crosshaped four throw design
with eight counterweights for balancing purposes.
The crankshaft is supported by five select fit main
bearings with the number three serving as the thrust
washer location. The main journals of the crankshaft
are cross drilled to improve rod bearing lubrication.
The number eight counterweight has provisions for
crankshaft position sensor target wheel mounting.
The select fit main bearing markings are located on
the rear side of the target wheel. The crankshaft oil
seals are one piece design. The front oil seal is
retained in the timing chain cover, and the rear seal
is pressed in to a bore formed by the cylinder block
and the bedplate assembly.
REMOVAL
NOTE: To remove the crankshaft from the engine,
the engine must be removed from the vehicle.
(1) Remove the engine. (Refer to 9 - ENGINE -
REMOVAL).
(2) Remove the engine oil pump.(Refer to 9 -
ENGINE/LUBRICATION/OIL PUMP - REMOVAL).
CAUTION: DO NOT pry on the oil pan gasket when
removing the oil pan, The oil pan gasket is mounted
to the cylinder block in three locations and will
remain attached to block when removing oil pan.
Gasket can not be removed with oil pan.
(3) Remove oil pan. (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - REMOVAL).
(4) Remove the oil pump pickup tube and oil pan
gasket /windage tray.
(5) Remove the bedplate mounting bolts. Note the
location of the three stud bolts for installation.
(6) Remove the connecting rods from the crank-
shaft.
CAUTION: The bedplate to cylinder block mating
surface is a critical sealing surface. Do not pry on
or damage this surface in anyway.
NOTE: The bedplate contains the lower main bear-
ing halves. Use care when handling bedplate as not
to drop or damage bearing halves. Installing main
bearing halves in the wrong position will cause
sever damage to the crankshaft.
Fig. 55 Engine Core Plug Removal
1 - CYLINDER BLOCK
2 - REMOVE PLUG WITH PLIERS
3 - STRIKE HERE WITH HAMMER
4 - DRIFT PUNCH
5 - CUP PLUG
DRENGINE - 4.7L 9 - 131

NOTE: The bedplate has pry points cast into it. Use
these points only. The pry points are on both the
left and right sides, only the left side is shown.
(7) Carefully pry on the pry points (Fig. 56) to
loosen the bedplate then remove the bedplate.
CAUTION: When removing the crankshaft, use care
not to damage bearing surfaces on the crankshaft.
(8) Remove the crankshaft.
(9) Remove the crankshaft target wheel.
INSPECTION
NOTE: Thoroughly inspect the connecting rod bear-
ing bores and main bearing bores for scoring, blue-
ing or severe scratches. Further disassembly may
be required.
If connecting rod bearing bores show damage, the
cylinder heads must be removed to service the piston
and rod assemblies. If the bedplate or the cylinder
block main bearing bores show damage the engine
must be replaced.
(1) If required, remove the main bearing halves
from the cylinder block and bedplate.(2) Thoroughly clean the bedplate to cylinder block
sealing surfaces and main bearing bores. Remove all
oil and sealant residue.
(3) Inspect the bedplate main bearing bores for
cracks, scoring or severe blueing. If either condition
exists the engine must be replaced.
(4) Inspect the crankshaft thrust washers for scor-
ing, scratches, wear or blueing. If either condition
exist replace the thrust washer.
(5) Inspect the oil pan gasket/windage tray for
splits, tears or cracks in the gasket sealing surfaces.
Replace gasket as necessary.
INSTALLATION
CAUTION: Main bearings are select fit. (Refer to 9 -
ENGINE/ENGINE BLOCK/CRANKSHAFT MAIN
BEARINGS - STANDARD PROCEDURE) for proper
bearing selections.
(1) Lubricate upper main bearing halves with
clean engine oil.
CAUTION: When installing crankshaft, use care not
to damage bearing surfaces on the crankshaft.
NOTE: Apply sealant to the target wheel retaining
screws prior to installation.
(2) Install the crankshaft target wheel. Torque the
mounting screws to 15 N´m (12 ft. lbs.).
(3) Position crankshaft in cylinder block.
(4) Install the thrust washers (Fig. 57).
Fig. 56 Bedplate Pry Point Location
1 - CYLINDER BLOCK
2 - BEDPLATE
3 - PRY POINT
Fig. 57 Crankshaft Thrust Washer Installation
1 - CRANKSHAFT THRUST WASHER
9 - 132 ENGINE - 4.7LDR
CRANKSHAFT (Continued)

(10) Position the oil pan gasket/windage tray,
using a new o-ring, install the oil pickup tube.
Torque the bolt to 28N´n (20 ft. lbs.) torque the nuts
to 28N´m (20 ft. lbs.).
(11) Install the oil pan. Torque the retaining bolts
to 15 N´m (11 ft. lbs.) in the sequence shown (Fig.
61).
(12) Install the engine (Refer to 9 - ENGINE -
INSTALLATION).CRANKSHAFT MAIN
BEARINGS
STANDARD PROCEDUREÐCRANKSHAFT MAIN
BEARING - FITTING
MAIN BEARING JOURNAL DIAMETER
(CRANKSHAFT REMOVED)
Crankshaft removed from the cylinder block.
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.
CRANKSHAFT MAIN BEARING SELECTION
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. 62). These marks
are read from left to right, corresponding with jour-
Fig. 60 Bedplate Tightening Sequence
1 - BEDPLATE2 - CYLINDER BLOCK
Fig. 61 Oil Pan Tightening Sequence
9 - 134 ENGINE - 4.7LDR
CRANKSHAFT (Continued)

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

(4) Install Special Tool 8507 Connecting Rod
Guides into connecting rod bolt threads (Fig. 74).
(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. 75).
(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).
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.
Fig. 74 PISTON AND CONNECTING ROD
INSTALLATION
1 - ªFº TOWARD FRONT OF ENGINE
2 - OIL SLINGER SLOT
3 - RING COMPRESSOR
4 - SPECIAL TOOL 8507
Fig. 75 PISTON AND CONNECTING ROD
ORIENTATION
1 - MAJOR THRUST SIDE OF PISTON
2 - OIL SLINGER SLOT
DRENGINE - 4.7L 9 - 141
PISTON & CONNECTING ROD (Continued)

(7) The No. 1 and No. 2 piston rings have a differ-
ent cross section. Ensure No. 2 ring is installed with
manufacturers I.D. mark (Dot) facing up, towards top
of the piston.
NOTE: Piston rings are installed in the following
order:
²Oil ring expander.
²Upper oil ring side rail.
²Lower oil ring side rail.
²No. 2 Intermediate piston ring.
²No. 1 Upper piston ring.
(8) Install the oil ring expander.
(9) Install upper side rail (Fig. 78) 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. 79).
(11) Install No. 1 upper piston ring using a piston
ring installer (Fig. 79).
(12) Position piston ring end gaps as shown in
(Fig. 80). 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.
Fig. 78 Side Rail - Installation
1 - SIDE RAIL END
Fig. 79 Upper and Intermediate Rings - Installation
Fig. 80 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
DRENGINE - 4.7L 9 - 143
PISTON RINGS (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)