check engine DODGE RAM 2002 Service Repair Manual

(4) Remove valve retaining locks, valve spring
retainers and valve springs. Check for abnormal
wear, replace as required.
(5) Remove the valve stem seals.
(6) Before removing valves, remove any burrs from
valve stem lock grooves to prevent damage to the
valve guides. Identify valves to ensure installation in
original location.
CLEANING
Clean valves thoroughly. Discard burned, warped,
or cracked valves.
Remove carbon and varnish deposits from inside of
valve guides with a reliable guide cleaner.
INSPECTION
Measure valve stems for wear. If wear exceeds
0.051 mm (0.002 in.), replace the valve.
Measure valve stem guide clearance as follows:
(1) Install Valve Guide Sleeve Tool C-3973 over
valve stem and install valve (Fig. 23). The special
sleeve places the valve at the correct height for
checking with a dial indicator.
(2) Attach dial indicator Tool C-3339 to cylinder
head and set it at right angles to valve stem being
measured (Fig. 24).
(3) Move valve to and from the indicator. The total
dial indicator reading should not exceed 0.432 mm
(0.017 in.). Ream the guides for valves with oversize
stems if dial indicator reading is excessive or if the
stems are scuffed or scored.
INSTALLATION
INSTALLATIONÐVALVE STEM SEAL
(1) Install new seal onto valve stem.
(2) Position valve spring onto valve stem.
(3) Position Valve Spring Compressor with Adapter
Studs onto cylinder head
(4) Compress valve spring and install retainer
valve locks.
(5) Remove air hose and adapter from spark plug
hole.
(6) Remove Valve Spring Compressor and Adapter
Studs.
(7) Install rocker arms (Refer to 9 - ENGINE/CYL-
INDER HEAD/ROCKER ARM / ADJUSTER ASSY -
INSTALLATION).
(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
Fig. 22 Valve Spring Compressor MD-998772A with
Adaptor 6716-A and Screw 6765
1 - SPECIAL TOOL MD 998772A
2 - SPECIAL TOOL 6765
3 - SPECIAL TOOL 6716A
4 - AIR HOSE
Fig. 23 Positioning Valve with Tool C-3973
1 - VALVE
2 - SPACER TOOL
Fig. 24 Measuring Valve Guide Wear
1 - VALVE
2 - SPECIAL TOOL C-3339
BR/BEENGINE 8.0L 9 - 83
INTAKE/EXHAUST VALVES & SEATS (Continued)

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. 25).
(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. 26). 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).
(1) Install the push rods in the same order as
removed.
(2) Install rocker arm assemblies in the same
order as removed. Tighten the rocker arm bolts to 28
N´m (21 ft. lbs.) torque.
(3) Install cylinder head cover and gasket (Refer to
9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(4) Connect spark plug wires.
Fig. 25 Cylinder Head Covers
1 - CYLINDER HEAD COVER
2 - CYLINDER HEAD COVER GASKET
9 - 84 ENGINE 8.0LBR/BE
INTAKE/EXHAUST VALVES & SEATS (Continued)

ENGINE BLOCK
CLEANING
Clean cylinder block thoroughly and check all core
hole plugs for evidence of leaking.
INSPECTION
Examine block for cracks or fractures.
The cylinder walls should be checked for out-of-
round and taper with Cylinder Bore Indicator Tool,
Special tool 6879 or equivalent. The cylinder block
should be bored and honed with new pistons and
rings fitted if:
²The cylinder bores show more than 0.127 mm
(0.005 inch) out-of-round.
²The cylinder bores show a taper of more than
0.254 mm (0.010 inch).
²The cylinder walls are badly scuffed or scored.
Boring and honing operation should be closely coor-
dinated with the fitting of pistons and rings so spec-
ified clearances may be maintained.
CAMSHAFT & BEARINGS (IN
BLOCK)
REMOVAL
REMOVALÐCAMSHAFT BEARINGS
This procedure requires that the engine is removed
from the vehicle.
(1) With engine completely disassembled, drive out
rear cam bearing core hole plug.NOTE: It is not advisable to attempt to replace cam-
shaft bearings unless special removal and installa-
tion tools are available, such as recommended tool
8544 Camshaft Bushing Remover Installer.
(2) Using recommended tool 8544 Camshaft Bush-
ing Remover Installer, Drive out bearing shells.
REMOVALÐCAMSHAFT
(1) Remove rocker arms and push rods (Refer to 9
- ENGINE/CYLINDER HEAD/ROCKER ARM /
ADJUSTER ASSY - REMOVAL). Identify each part
so it can be installed in its original location.
NOTE: The 4 corner tappets can not be removed
without removing the cylinder heads and gaskets.
However, they can be lifted and retained for cam-
shaft removal.
(2) Remove the Bolts retaining the yoke retaining
spider. Remove the yoke retaining spider, tappet
aligning yokes and tappets.
(3) Remove upper and lower intake manifolds
(Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANI-
FOLD - REMOVAL).
(4) Remove timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL) and timing chain and
sprockets (Refer to 9 - ENGINE/VALVE TIMING/
TIMING BELT/CHAIN AND SPROCKETS -
REMOVAL).
(5) Remove camshaft thrust plate (Fig. 27).
(6) Install a long bolt into front of camshaft to aid
in removal of the camshaft. Remove camshaft, being
careful not to damage cam bearings with the cam
lobes.
Fig. 26 Rocker Arm
1 - ROCKER ARMS
2 - ROCKER ARM PEDESTALS
3 - RETAINER
Fig. 27 Camshaft
1 - CAMSHAFT
2 - THRUST PLATE
BR/BEENGINE 8.0L 9 - 85
ROCKER ARM / ADJUSTER ASSY (Continued)

INSTALLATION
INSTALLATIONÐCAMSHAFT BEARINGS
(1) Install new camshaft bearings using recom-
mended Tool 8544 Camshaft Bushing Remover
Installer, by sliding the new camshaft bearing shell
over proper adapter.
(2) Bearings must be carefully aligned to bring oil
holes into full register with oil passages from the
main bearing. If the camshaft bearing shell oil holes
are not in exact alignment, remove and install them
correctly. Install a new core hole plug at the rear of
camshaft.Be sure this plug does not leak.
INSTALLATIONÐCAMSHAFT
(1) Lubricate camshaft lobes and camshaft bearing
journals. Using a long bolt, insert the camshaft into
the cylinder block.
NOTE: Whenever an engine has been rebuilt, a new
camshaft and/or new tappets installed, add 1 pint of
MoparTCrankcase Conditioner, or equivalent. The
oil mixture should be left in engine for a minimum
of 805 km (500 miles). Drain at the next normal oil
change.
(2) Install camshaft thrust plate. Tighten the torx
bolts to 22 N´m (16 ft. lbs.) torque.
(3) Check camshaft end play. The end play should
be 0.051-0.152 mm (0.002-0.006 inch) with a new
thrust plate and up to 0.254 mm (0.010 inch) with a
used thrust plate. If not within these limits install a
new thrust plate.
(4) Line up key with keyway in sprocket, then
using Special Tools C-3688, C-3718 and MB990799
install crankshaft timing sprocket. Make sure the
sprocket seats against the crankshaft shoulder (Fig.
28).
(5) Install timing chain and sprocket (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT/CHAIN
AND SPROCKETS - INSTALLATION).
(6) Install the timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).
(7) Install the crankshaft pulley/damper (Refer to
9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - INSTALLATION).
(8) Prime oil pump by squirting oil in the oil filter
mounting hole and filling the J-trap of the front tim-
ing cover. When oil is running out, install oil filter
that has been filled with oil.
(9) Each tappet reused must be installed in the
same position from which it was removed.When
camshaft is replaced, all of the tappets must be
replaced.(10) Install tappets and push rods in their original
location.
(11) Position the tappet aligning yokes and yoke
retaing spider.
(12) Install the retaining spider mounting bolts.
Tighten bolts to 22 N´m (16 ft. lbs.).
(13) Install the rocker arms (Refer to 9 - ENGINE/
CYLINDER HEAD/ROCKER ARM / ADJUSTER
ASSY - INSTALLATION).
(14) 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.
(15) Install cylinder head cover (Fig. 29) (Refer to
9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(16) Install the intake manifolds (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION).
(17) Start engine and check for leaks.
Fig. 28 Crankshaft Sprocket Installation
1 - SPECIAL TOOL C-3688
2 - SPECIAL TOOL C-3718
3 - SPECIAL TOOL MD990799
9 - 86 ENGINE 8.0LBR/BE
CAMSHAFT & BEARINGS (IN BLOCK) (Continued)

(1) Start bearing in place, and insert Crankshaft
Main Bearing Remover/Installer Tool C-3059 into oil
hole of crankshaft (Fig. 31).
(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.
32).
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. 33).
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.
Fig. 32 Timing Chain Cover and Oil Seal
1 - TIMING CHAIN COVER
2 - OIL SEAL
Fig. 33 Timing Chain Cover and Oil Seal
1 - SPECIAL TOOL C-3688
2 - SPECIAL TOOL 6806
BR/BEENGINE 8.0L 9 - 89
CRANKSHAFT MAIN BEARINGS (Continued)

INSTALLATIONÐFRONT OIL SEAL - FRONT
COVER REMOVED
(1) Position the crankshaft front oil seal onto seal
installer special tool 6806.
(2) Use tool 6761 to support timing chain cover
when installing oil seal with tool 6806 (Fig. 34),
install seal (Fig. 35).
(3) Install engine front cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).
CRANKSHAFT OIL SEAL -
REAR
REMOVAL
NOTE: This procedure does not require the removal
of the seal retainer from the engine block.
(1) Remove the transmission.
(2) Carefully, remove the rear seal from the
retainer. Discard the oil seal.
INSTALLATION
(1) Wash all parts in a suitable solvent and inspect
carefully for damage or wear.(2) Position Special Tool 6687 Seal Guide, onto the
crankshaft.
(3) Position the oil seal onto the Seal guide, then
using Special Tool 8359 Seal Installer and C±4171
Driver Handle, Install the oil seal.
(4) The seal face surface must be countersunk into
the retainer .762±1.27mm (0.030±0.050 in.).
(5) Install the transmission.
(6) Check and verify engine oil is at correct level.
(7) Start engine and check for leaks.
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.
Fig. 34 Oil Seal, ToolsÐ6806 and 6761
1 - FRONT COVER
2 - SPECIAL TOOL 6761
3 - FRONT OIL SEAL
4 - SPECIAL TOOL 6806
Fig. 35 Oil Seal Installed
1 - SPECIAL TOOL 6806
2 - SPECIAL TOOL 6761
9 - 90 ENGINE 8.0LBR/BE
CRANKSHAFT OIL SEAL - FRONT (Continued)

(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 havebeen 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.
(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. 36).
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.
BR/BEENGINE 8.0L 9 - 91
CRANKSHAFT REAR OIL SEAL RETAINER (Continued)

(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. 37).
(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.
Fig. 36 Leak-Down Tester
1 - POINTER
2 - WEIGHTED ARM
3 - RAM
4 - CUP
5 - HANDLE
6 - PUSH ROD
Fig. 37 Tappets, Aligning Yoke and Yoke Retaining
Spider
1 - TAPPET ALIGNING YOLK
2 - YOKE RETAINING SPIDER
3 - TAPPET
9 - 92 ENGINE 8.0LBR/BE
HYDRAULIC LIFTERS (Continued)

37). 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. 38) 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.
STANDARD PROCEDUREÐPISTON FITTING
Piston and cylinder wall must be clean and dry.
Specified clearance between the piston and the cylin-
der wall is 0.013-0.038 mm (0.0005-0.0015 inch). The
max. allowable clearance is 0.0762 mm (0.003 in.).Piston diameter should be measured at the top of
skirt, 90É to piston pin axis. Cylinder bores should be
measured halfway down the cylinder bore and trans-
verse to the engine crankshaft center line.
Pistons and cylinder bores should be measured at
normal room temperature, 21ÉC (70ÉF).
(1) To correctly select the proper size piston, a cyl-
inder bore gauge, capable of reading in .00019
INCREMENTS is required (Fig. 39). If a bore gauge
is not available, do not use an inside micrometer.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
accurate results. 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
.00019increments is required.Piston installation into
the cylinder bore require slightly more pressure than
that required for non-coated pistons. The bonded
Fig. 38 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
BR/BEENGINE 8.0L 9 - 93
HYDRAULIC LIFTERS (Continued)

coating on the piston will give the appearance of a
line-to-line fit with the cylinder bore.
REMOVAL
(1) Remove the engine from the vehicle (Refer to 9
- ENGINE - REMOVAL).
(2) Remove cylinder head (Refer to 9 - ENGINE/
CYLINDER HEAD - REMOVAL).
(3) Remove the oil pan and oil pump pick-up tube
(Refer to 9 - ENGINE/LUBRICATION/OIL PAN -
REMOVAL).
(4) Remove top ridge of cylinder bores with a reli-
able ridge reamer before removing pistons from cyl-
inder block. Be sure to keep tops of pistons covered
during this operation.
(5) Be sure the connecting rod and connecting rod
cap are identified with the cylinder number. Remove
connecting rod cap. Install connecting rod bolt guide
set on connecting rod bolts.
(6) Pistons and connecting rods must be removed
from top of cylinder block. When removing piston and
connecting rod assemblies, rotate crankshaft center
the connecting rod in the cylinder bore and at BDC.
Be careful not to nick crankshaft journals. DO
NOT try to remove black coating on skirt. This
is the dry film lubricant.
(7) After removal, install bearing cap on the mat-
ing rod.
CLEANING
Clean the piston and connecting rod assembly
using a suitable solvent.
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) Check the crankshaft connecting rod journal
for excessive wear, taper and scoring.
(2) Check the cylinder block bore for out-of-round,
taper, scoring and scuffing.
(3) Be sure that compression ring gaps are stag-
gered so that neither is in line with oil ring rail gap.
(4) Before installing the ring compressor, make
sure the oil ring expander ends are butted and the
rail gaps located properly (Fig. 40).
NOTE: Be sure position of rings does not change
during the following step.
(5) Immerse the piston head and rings in clean
engine oil. Slide Piston Ring Compressor Tool C-385
over the piston and tighten with the special wrench
(part of Tool C-385).
(6) Install connecting rod bolt protectors on rod
bolts, a long protector should be installed on the
numbered side of the connecting rod.
(7) Rotate crankshaft so that the connecting rod
journal is on the center of the cylinder bore in the
bottom dead center (BDC) position. Be sure connect-
ing rod and cylinder bore number are the same.
Insert rod and piston into cylinder bore. Be sure the
piston and rod assemblies are installed in the proper
orientation (Fig. 41).
(8) The notch, groove or arrow on top of piston
must be pointing toward front of engine. The larger
chamfer of the connecting rod bore must be installed
toward crankshaft journal fillet.
(9) While tapping the piston down in cylinder bore
with the handle of a hammer, guide the connecting
rod over the crankshaft journal.
Fig. 39 Bore Gauge
1 - BORE GAUGE
2 - CYLINDER BORE
3 - 2-5/16 in.
9 - 94 ENGINE 8.0LBR/BE
PISTON & CONNECTING ROD (Continued)