
(8) The cylinder head cover gasket can be used
again. Install the gasket onto the head rail.For the
left side the number tab is at the front of
engine with the number up. For the right side
the number tab is at the rear of engine with the
number up.
CAUTION: The cylinder head cover fasteners have a
special plating. DO NOT use alternative fasteners.
(9) Install cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION) (Fig. 24).
(10) Install closed crankcase ventilation system.
(11) Connect the evaporation control system.
(12) Install air cleaner.
(13) Connect the negative cable to the battery.
(14) Road test vehicle and check for leaks.
INSTALLATIONÐVALVES AND VALVE SPRINGS
(1) Clean valves thoroughly. Discard burned,
warped and cracked valves.(2) Remove carbon and varnish deposits from
inside of valve guides with a reliable guide cleaner.
(3) Measure valve stems for wear. If wear exceeds
0.051 mm (0.002 inch), replace the valve.
(4) Make sure there are no burrs on valve stems.
(5) Coat valve stems with lubrication oil. Insert
valves into valve guides in cylinder head.
(6) Install new seals on all valve guides(BLACK
on intake and BROWN on exhaust). Install valve
springs and valve retainers.
(7) Compress valve springs with Valve Spring
Compressor Tool MD-998772A and adapter 6716A,
install locks and release tool. Tap the retainer with a
brass or heavy plastic hammer to ensure locks have
been seated.
(8) If valves and/or seats were ground, measure
the installed height of springs. Make sure the mea-
surement is taken from bottom of spring seat in cyl-
inder head to the bottom surface of spring retainer. If
spacers are installed, measure from the top of spacer.
If height is greater than 42.86 mm (1-11/16 inches),
install a 1.587 mm (1/16 inch) spacer in head coun-
terbore. Ensure this brings spring height back to nor-
mal, 41.27 to 42.86 mm (1-5/8 to 1-11/16 inch).
(9) Install the cylinder head (Refer to 9 - ENGINE/
CYLINDER HEAD - INSTALLATION).
ROCKER ARM / ADJUSTER
ASSY
REMOVAL
(1) Disconnect spark plug wires by pulling the boot
straight out in line with plug.
(2) Remove cylinder head cover and gasket (Refer
to 9 - ENGINE/CYLINDER HEAD/CYLINDER
HEAD COVER(S) - REMOVAL).
(3) Remove the rocker arm bolts and the rocker
arm assembly (Fig. 25). Place rocker arm assemblies
on a bench in the same order as removed.
(4) Remove the push rods and place them on a
bench in the same order as removed.
INSTALLATION
CAUTION: DO NOT rotate or crank the engine dur-
ing or immediately after rocker arm installation.
Allow the hydraulic roller tappets adequate time to
bleed down (about 5 minutes).
Fig. 24 Cylinder Head Covers
1 - CYLINDER HEAD COVER
2 - CYLINDER HEAD COVER GASKET
DRENGINE 8.0L 9 - 379
INTAKE/EXHAUST VALVES & SEATS (Continued)

(1) Start bearing in place, and insert Crankshaft
Main Bearing Remover/Installer Tool C-3059 into oil
hole of crankshaft (Fig. 30).
(2) Slowly rotate crankshaft counterclockwise slid-
ing the bearing into position. Remove Tool C-3059.
(3) Lubricate the main journals with clean engine
oil. Install main bearing caps and bolts. Follow the 2
step tightening sequence, starting with No. 1 main
bearing cap.
(4) Apply a rearward axial load of 667 N (150
lbs-f) on crankshaft centerline, driving No.3 main cap
and thrust bearing against No.3 bulkhead. Repeat
procedure, driving crankshaft forward to align rear
flange of thrust bearings in a common plane. Front
face of No.1 main cap must not extend forward in
front of face of No.1 bulkhead.
(5) Install the oil pump pick-up tube and oil pan
(Refer to 9 - ENGINE/LUBRICATION/OIL PAN -
INSTALLATION).
CRANKSHAFT OIL SEAL -
FRONT
REMOVAL
REMOVALÐFRONT OIL SEAL - FRONT COVER
INSTALLED
(1) Disconnect the negative cable from the battery.
(2) Remove vibration damper from the crankshaft
(Refer to 9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL).(3) Place a suitable tool behind the lips of the oil
seal to pry the oil seal outward. Be careful not to
damage the crankshaft seal surface of the cover (Fig.
31).
REMOVALÐFRONT OIL SEAL - FRONT COVER
REMOVED
(1) Remove engine front cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL).
(2) Place a suitable tool behind the lips of the oil
seal to pry the oil seal outward. Be careful not to
damage the crankshaft seal surface of the cover.
INSTALLATION
INSTALLATIONÐFRONT OIL SEAL ± FRONT
COVER INSTALLED
(1) Position the crankshaft front oil seal onto seal
installer special tool 6806 and C-3688 (Fig. 32).
Install seal.
(2) Install vibration damper (Refer to 9 - ENGINE/
ENGINE BLOCK/VIBRATION DAMPER - INSTAL-
LATION).
(3) Install serpentine belt (Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS - INSTALLA-
TION).
(4) Install cooling fan and shroud (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - INSTALLA-
TION).
(5) Connect negative cable to the battery.
(6) Start engine and check for leaks.
INSTALLATIONÐFRONT OIL SEAL - FRONT
COVER REMOVED
(1) Position the crankshaft front oil seal onto seal
installer special tool 6806.
Fig. 30 Upper Main Bearing Removal and
Installation with Tool C-3059
1 - SPECIAL TOOL C-3059
2 - BEARING
3 - SPECIAL TOOL C-3059
4 - BEARINGFig. 31 Timing Chain Cover and Oil Seal
1 - TIMING CHAIN COVER
2 - OIL SEAL
9 - 384 ENGINE 8.0LDR
CRANKSHAFT MAIN BEARINGS (Continued)

CRANKSHAFT REAR OIL SEAL
RETAINER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove the transmission.
(3) Remove the drive plate / flywheel.
(4) Remove the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL).
(5) Remove the rear oil seal retainer mounting
bolts.
(6) Carefully remove the retainer from the engine
block.
INSTALLATION
(1) Throughly clean all gasket resdue from the
engine block.
(2) Use extream care and clean all gasket resdue
from the retainer.
(3) Apply a small amount of MopartSilicone Rub-
ber Adhesive Sealant to the retainer gasket. Position
the gasket onto the retainer.
(4) Position Special Tool 6687 Seal Guide onto the
crankshaft.
(5) Position the retainer and seal over the guide
and onto the engine block.
(6) Install the retainer mounting bolts. Tighten the
bolts to 22 N´m (16 ft. lbs.).
(7) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
(8) Install the drive plate / flywheel.
(9) Install the transmission.
(10) Check and verify engine oil level.
(11) Start engine and check for leaks.
HYDRAULIC LIFTERS
DIAGNOSIS AND TESTINGÐHYDRAULIC
TAPPETS
Before disassembling any part of the engine to cor-
rect tappet noise, check the oil pressure. If vehicle
has no oil pressure gauge, install a reliable gauge at
the pressure sending-unit. The pressure should be
between 207-552 kPa (30-80 psi) at 3,000 RPM.
Check the oil level after the engine reaches normal
operating temperature. Allow 5 minutes to stabilize
oil level, check dipstick. The oil level in the pan
should never be above the FULL mark or below the
ADD OIL mark on dipstick. Either of these two con-
ditions could be responsible for noisy tappets.
OIL LEVEL
HIGH
If oil level is above the FULL mark, it is possible
for the connecting rods to dip into the oil. With the
engine running, this condition could create foam in
the oil pan. Foam in oil pan would be fed to the
hydraulic tappets by the oil pump causing them to
lose length and allow valves to seat noisily.
LOW
Low oil level may allow oil pump to take in air.
When air is fed to the tappets, they lose length,
which allows valves to seat noisily. Any leaks on
intake side of oil pump through which air can be
drawn will create the same tappet action. Check the
lubrication system from the intake strainer to the
pump cover, including the relief valve retainer cap.
When tappet noise is due to aeration, it may be
intermittent or constant, and usually more than one
tappet will be noisy. When oil level and leaks have
been corrected, operate the engine at fast idle. Run
engine for a sufficient time to allow all of the air
inside the tappets to be bled out.
TAPPET NOISE DIAGNOSIS
(1) To determine source of tappet noise, operate
engine at idle with cylinder head covers removed.
(2) Feel each valve spring or rocker arm to detect
noisy tappet. The noisy tappet will cause the affected
spring and/or rocker arm to vibrate or feel rough in
operation.
NOTE: Worn valve guides or cocked springs are
sometimes mistaken for noisy tappets. If such is
the case, noise may be dampened by applying side
thrust on the valve spring. If noise is not apprecia-
bly reduced, it can be assumed the noise is in the
tappet. Inspect the rocker arm push rod sockets
and push rod ends for wear.
(3) Valve tappet noise ranges from light noise to a
heavy click. A light noise is usually caused by exces-
sive leak-down around the unit plunger, or by the
plunger partially sticking in the tappet body cylinder.
The tappet should be replaced. A heavy click is
caused by a tappet check valve not seating, or by for-
eign particles wedged between the plunger and the
tappet body. This will cause the plunger to stick in
the down position. This heavy click will be accompa-
nied by excessive clearance between the valve stem
and rocker arm as valve closes. In either case, tappet
assembly should be removed for inspection and clean-
ing.
9 - 386 ENGINE 8.0LDR

(4) The valve train generates a noise very much
like a light tappet noise during normal operation.
Care must be taken to ensure that tappets are mak-
ing the noise. If more than one tappet seems to be
noisy, it's probably not the tappets.
LEAK-DOWN TEST
After cleaning and inspection, test each tappet for
specified leak-down rate tolerance to ensure zero-lash
operation (Fig. 35).
Swing the weighted arm of the hydraulic valve tap-
pet tester away from the ram of the Universal Leak-
Down Tester.
(1) Place a 7.925-7.950 mm (0.312-0.313 inch)
diameter ball bearing on the plunger cap of the tap-
pet.
(2) Lift the ram and position the tappet (with the
ball bearing) inside the tester cup.
(3) Lower the ram, then adjust the nose of the ram
until it contacts the ball bearing. DO NOT tighten
the hex nut on the ram.
(4) Fill the tester cup with hydraulic valve tappet
test oil until the tappet is completely submerged.
(5) Swing the weighted arm onto the push rod and
pump the tappet plunger up and down to remove air.
When the air bubbles cease, swing the weighted arm
away and allow the plunger to rise to the normal
position.
(6) Adjust the nose of the ram to align the pointer
with the SET mark on the scale of the tester and
tighten the hex nut.
(7) Slowly swing the weighted arm onto the push
rod.
(8) Rotate the cup by turning the handle at the
base of the tester clockwise one revolution every 2
seconds.
(9) Observe the leak-down time interval from the
instant the pointer aligns with the START mark on
the scale until the pointer aligns with the 0.125
mark. A normally functioning tappet will require
20-110 seconds to leak-down. Discard tappets with
leak-down time interval not within this specification.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Remove the air cleaner.
(3) Remove cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(4) Remove rocker arm assembly and push rods
(Refer to 9 - ENGINE/CYLINDER HEAD/ROCKER
ARM / ADJUSTER ASSY - REMOVAL). Identify
push rods to ensure installation in original location.
(5) Remove upper and lower intake manifold
(Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANI-
FOLD - REMOVAL).(6) Cut the cylinder head gasket for accessibility if
the end tappets are to be removed.
(7) Remove yoke retainer spider and tappet align-
ing yokes (Fig. 36).
Fig. 35 Leak-Down Tester
1 - POINTER
2 - WEIGHTED ARM
3 - RAM
4 - CUP
5 - HANDLE
6 - PUSH ROD
Fig. 36 Tappets, Aligning Yoke and Yoke Retaining
Spider
1 - TAPPET ALIGNING YOLK
2 - YOKE RETAINING SPIDER
3 - TAPPET
DRENGINE 8.0L 9 - 387
HYDRAULIC LIFTERS (Continued)

(8) Pull tappet out of bore with a twisting motion.
If all tappets are to be removed, identify tappets to
ensure installation in original location.
(9) If the tappet or bore in cylinder block is scored,
scuffed, or shows signs of sticking, ream the bore to
next oversize. Replace with oversize tappet.
(10) Check camshaft lobes for abnormal wear.
CLEANING
Clean tappet with a suitable solvent. Rinse in hot
water and blow dry with a clean shop rag or com-
pressed air.
INSTALLATION
(1) Lubricate tappets.
(2) Install tappets in their original positions.
Ensure that the oil bleed hole (if so equipped)
faces forward.
(3) Install tappet aligning yokes. Position the yoke
retainer spider over the tappet aligning yokes (Fig.
36)Install the yoke retaining spider bolts and tighten
to 22 N´m (16 ft. lbs.) torque.
(4) Install the push rods in their original location.
(5) Install the rocker arms (Refer to 9 - ENGINE/
CYLINDER HEAD/ROCKER ARM / ADJUSTER
ASSY - INSTALLATION).
(6) Install lower and upper intake manifold (Refer
to 9 - ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION).
(7) The cylinder head cover gasket can be used
again. Install the gasket onto the head rail.For the
left side the number tab is at the front of
engine with the number up. For the right side
the number tab is at the rear of engine with the
number up.
(8) Install cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(9) Install the air cleaner.
CAUTION: To prevent damage to valve mechanism,
engine must not be run above fast idle until all
hydraulic tappets have filled with oil and have
become quiet.
(10) Connect the negative cable to the battery.
(11) Road test vehicle and check for leaks.
PISTON & CONNECTING ROD
DESCRIPTION
The pistons (Fig. 37) are elliptically turned so that
the diameter at the pin boss is less than its diameter
across the thrust face. This allows for expansion
under normal operating conditions. Under operating
temperatures, expansion forces the pin bosses away
from each other, causing the piston to assume a more
nearly round shape.
All pistons are machined to the same weight,
regardless of size, to maintain piston balance.
The piston pin rotates in the piston only and is
retained by the press interference fit of the piston
pin in the connecting rod.
The pistons have a unique dry-film lubricant coat-
ing baked onto the skirts to reduce friction. The
lubricant is particularly effective during engine
break-in, but with time, the material becomes embed-
ded into cylinder bore walls and continues to reduce
friction.
The pistons are LH and RH bank specific.
Fig. 37 Piston and Connecting RodÐ8.0L Engine
1 - FRONT I.D. TOWARDS THIS SIDE
2 - ORIENTATION BUTTON TOWARDS REAR (R.H. ONLY)
2, 4, 6, 8, 10
3 - ORIENTATION BUTTON TOWARDS FRONT (L.H. ONLY)
1, 3, 5, 7, 9
9 - 388 ENGINE 8.0LDR
HYDRAULIC LIFTERS (Continued)

VIBRATION DAMPER
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Remove the following:
²Radiator fan (Refer to 7 - COOLING/ENGINE/
RADIATOR FAN - REMOVAL)
²Accessory drive belt (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - REMOVAL)
²Radiator (Refer to 7 - COOLING/ENGINE/RA-
DIATOR - REMOVAL)
(3) Remove crankshaft pulley/damper bolt and
washer from end of crankshaft.
(4) Using Special Tool, 1026 3 Jaw Puller and Spe-
cial Tool 8513 Insert, remove pulleyÐdamper from
the crankshaft (Fig. 45).
(5) Inspect crankshaft oil seal. If damaged or
worn, replace the front oil seal (Refer to 9 - ENGINE/
ENGINE BLOCK/CRANKSHAFT OIL SEAL -
FRONT - REMOVAL).
INSTALLATION
(1) Position the crankshaft pulley/damper onto the
crankshaft.
(2) Use Special Tool, C-3688 Crankshaft Pulley/
Damper Installer to press the pulleyÐdamper onto
the crankshaft. Install crankshaft bolt and washer
and tighten to 312 N´m (230 ft. lbs.) torque (Fig. 46).
(3) Install the following:
²Radiator (Refer to 7 - COOLING/ENGINE/RA-
DIATOR - INSTALLATION)²Accessory drive belt (Refer to 7 - COOLING/AC-
CESSORY DRIVE/DRIVE BELTS - INSTALLATION)
²Radiator fan (Refer to 7 - COOLING/ENGINE/
RADIATOR FAN - INSTALLATION)
(4) Connect the negative cable to the battery.
FRONT MOUNT
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Position fan to assure clearance for radiator top
tank and hose.
CAUTION: DO NOT lift the engine by the intake
manifold.
(3) Install engine support/lifting fixture.
(4) Raise vehicle on hoist.
(5) Lift the engine SLIGHTLY and remove the
thru-bolt and nut.
(6) Remove engine support bracket/cushion bolts.
Remove the support bracket/cushion and heat
shields.
INSTALLATION
(1) With engine raised SLIGHTLY, position the
engine support bracket/cushion and heat shields to
the block. Install new bolts and tighten to 81 N´m (60
ft. lbs.) torque.
(2) Install the thru-bolt and 2 piece rubber engine
rubber restrictors onto the engine support bracket/
cushion.
Fig. 45 Crankshaft PulleyÐDamper Removal
1-3JAWPULLER
Fig. 46 Installing Crankshaft PulleyÐDamper
1 - SPECIAL TOOL C-3688
9 - 392 ENGINE 8.0LDR

OIL FILTER
REMOVAL
All engines are equipped with a high quality full-
flow, disposable type oil filter. DaimlerChrysler Cor-
poration 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 to remove
it from the cylinder block oil filter boss (Fig. 51).
(4) When filter separates from adapter nipple, tip
gasket end upward to minimize oil spill. Remove fil-
ter from vehicle.
(5) With a wiping cloth, clean the gasket sealing
surface (Fig. 52) of oil and grime.
(6) Install new filter (Refer to 9 - ENGINE/LUBRI-
CATION/OIL FILTER - INSTALLATION).
INSTALLATION
(1) Lightly lubricate oil filter gasket with engine
oil or chassis grease.
(2) Thread filter onto adapter nipple. When gasket
makes contact with sealing surface, (Fig. 52) hand
tighten filter one full turn, do not over tighten.
(3) Add oil (Refer to 9 - ENGINE/LUBRICATION/
OIL - STANDARD PROCEDURE).
OIL PAN
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Raise vehicle.
(3) Drain engine oil.
(4) Remove left engine to transmission strut.
(5) Remove oil pan mounting bolts, pan and one-
piece gasket. The engine may have to be raised
slightly on 2WD vehicles.(6) Remove the oil pick-up tube assembly (Fig. 53).
Discard the gasket.
CLEANING
Clean the block and pan gasket surfaces.
If present, trim excess sealant from inside the
engine.
Clean oil pan in solvent and wipe dry with a clean
cloth.
Clean oil screen and pipe thoroughly in clean sol-
vent. Inspect condition of screen.
INSPECTION
Inspect oil drain plug and plug hole for stripped or
damaged threads. Repair as necessary.
Inspect oil pan mounting flange for bends or distor-
tion. Straighten flange, if necessary.
Fig. 51 Oil Filter RemovalÐTypical
1 - ENGINE OIL FILTER
2 - OIL FILTER WRENCH
Fig. 52 Oil Filter Sealing SurfaceÐTypical
1 - SEALING SURFACE
2 - RUBBER GASKET
3 - OIL FILTER
Fig. 53 Oil Pick-Up Tube
1 - PICKÐUP TUBE
2 - SEALANT AT SPLIT-LINES
3 - SEALANT AT SPLIT-LINE
DRENGINE 8.0L 9 - 397

INSTALLATION
(1) Fabricate 4 alignment dowels from 5/16x11/2
inch bolts. Cut the head off the bolts and cut a slot
into the top of the dowel. This will allow easier
installation and removal with a screwdriver (Fig. 54).
(2) Install the dowels in the cylinder block at the
four corners.
(3) Apply small amount of MopartSilicone Rubber
Adhesive Sealant, or equivalent at the split lines.
The split lines are between the cylinder block, the
timing chain cover and the rear crankshaft seal
assembly (Fig. 53).After the sealant is applied
you have 3 minutes to install the gasket and oil
pan.
(4) Slide the one-piece gasket over the dowels and
onto the block.
(5) Position the oil pan over the dowels and onto
the gasket. The engine may have to be slightly raised
on 2WD vehicles.
(6) Install the oil pan bolts (Fig. 55). Tighten the
bolts to as shown in Oil Pan Bolts Torque Chart.(7) Remove the dowels. Install the remaining 5/16
inch oil pan bolts. Torque these bolts as shown in Oil
Pan Bolts Torque Chart.
(8) Install the drain plug. Tighten drain plug to 34
N´m (25 ft. lbs.) torque.
(9) Install the engine to transmission strut.
(10) Lower vehicle.
(11) Connect the negative cable to the battery.
(12) Fill crankcase with oil to proper level.
(13) Start engine and check for leaks.
OIL PUMP
REMOVAL
(1) Remove the timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL).
(2) Remove the relief valve plug, gasket, spring
and valve (Fig. 56). Discard the gasket.
(3) Remove mounting screws and oil pump cover
(Fig. 57).
(4) Remove oil pump inner and outer rotors (Fig.
57).
(5) Inspect oil pump for wear (Refer to 9 -
ENGINE/LUBRICATION/OIL PUMP - INSPEC-
TION).
CLEANING
Wash all parts in a suitable solvent and inspect
carefully for damage or wear.
Fig. 54 Fabrication of Alignment Dowels
1 - 5/16º X 11¤2º BOLT
2 - DOWEL
3 - SLOT
Fig. 55 Oil Pan Bolt Location
1 - OIL PAN
2 - OIL FILTER
3 - STUD BOLTS
4 - DRAIN PLUG
Fig. 56 Oil Pressure Relief Valve
1 - TIMING CHAIN COVER
2 - OIL PUMP RELIEF VALVE
3 - SPRING
4 - GASKET
5 - PLUG
9 - 398 ENGINE 8.0LDR
OIL PAN (Continued)