
REMOVAL
The service seal is a two piece, Viton seal. The
upper seal half can be installed with crankshaftremoved from engine or with crankshaft installed.
When a new upper seal is installed, install a new
lower seal. The lower seal half can be installed only
with the rear main bearing cap removed.
UPPER SEAL ÐCRANKSHAFT REMOVED
(1) Remove the crankshaft (Refer to 9 - ENGINE/
ENGINE BLOCK/CRANKSHAFT - REMOVAL). Dis-
card the old upper seal.
UPPER SEALÐCRANKSHAFT INSTALLED
(1) Remove the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL).
(2) Remove the oil pump (Refer to 9 - ENGINE/
LUBRICATION/OIL PUMP - REMOVAL).
(3) Remove the rear main bearing cap. Remove
and discard the old lower oil seal.
(4) Carefully remove and discard the old upper oil
seal.
LOWER SEAL
(1) Remove the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL).
(2) Remove the oil pump (Refer to 9 - ENGINE/
LUBRICATION/OIL PUMP - REMOVAL).
(3) Remove the rear main bearing cap and discard
the old lower seal.
INSTALLATION
The service seal is a two piece, Viton seal. The
upper seal half can be installed with crankshaft
removed from engine or with crankshaft installed.
When a new upper seal is installed, install a new
lower seal. The lower seal half can be installed only
with the rear main bearing cap removed.
UPPER SEAL ÐCRANKSHAFT REMOVED
(1) Clean the cylinder block rear cap mating sur-
face. Be sure the seal groove is free of debris. Check
for burrs at the oil hole on the cylinder block mating
surface to rear cap.
(2) Lightly oil the new upper seal lips with engine
oil.
(3) Install the new upper rear bearing oil seal with
the white paint facing toward the rear of the engine.
(4) Position the crankshaft into the cylinder block.
(5) Lightly oil the new lower seal lips with engine
oil.
(6) Install the new lower rear bearing oil seal into
the bearing cap with the white paint facing towards
the rear of the engine.
(7) Apply 5 mm (0.20 in.) drop of MopartGasket
Maker, or equivalent, on each side of the rear main
bearing cap (Fig. 33). DO NOT over-apply sealant or
allow the sealant to contact the rubber seal. Assem-
Fig. 31 Position Tool and Seal onto Crankshaft
1 - SPECIAL TOOL 6635
2 - OIL SEAL
3 - TIMING CHAIN COVER
Fig. 32 Installing Oil Seal
1 - SPECIAL TOOL 6635
2 - TIMING CHAIN COVER
BR/BEENGINE 3.9L 9 - 35
CRANKSHAFT OIL SEAL - REAR (Continued)

ble bearing cap to cylinder block immediately after
sealant application.
(8) To align the bearing cap, use cap slot, align-
ment dowel, and cap bolts. DO NOT remove excess
material after assembly. DO NOT strike rear cap
more than two times for proper engagement.
(9) Clean and oil all cap bolts. Install all main
bearing caps. Install all cap bolts and alternately
tighten to 115 N´m (85 ft. lbs.) torque.
(10) Install oil pump (Refer to 9 - ENGINE/LU-
BRICATION/OIL PUMP - INSTALLATION).
(11) Apply MopartGEN II Silicone Rubber Adhe-
sive Sealant, or equivalent, at bearing cap-to-block
joint to provide cap to block and oil pan sealing (Fig.
34). Apply enough sealant so that a small amount is
squeezed out. Withdraw nozzle and wipe excess seal-
ant off the oil pan seal groove.
(12) Install new front crankshaft oil seal (Refer to
9 - ENGINE/ENGINE BLOCK/CRANKSHAFT OIL
SEAL - FRONT - INSTALLATION).
(13) Immediately install the oil pan (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
UPPER SEALÐCRANKSHAFT INSTALLED
(1) Clean the cylinder block mating surfaces before
oil seal installation. Check for burrs at the oil hole on
the cylinder block mating surface to rear cap.
(2) Lightly oil the new upper seal lips with engine
oil. To allow ease of installation of the seal, loosen at
least the two main bearing caps forward of the rear
bearing cap.(3) Rotate the new upper seal into the cylinder
block, being careful not to shave or cut the outer sur-
face of the seal. To ensure proper installation, use the
installation tool provided with the kit. Install the
new seal with the white paint facing toward the rear
of the engine.
(4) Install the new lower rear bearing oil seal into
the bearing cap with the white paint facing toward
the rear of the engine.
(5) Apply 5 mm (0.20 in.) drop of MopartGasket
Maker, or equivalent, on each side of the rear main
bearing cap (Fig. 33). DO NOT over-apply sealant or
allow the sealant to contact the rubber seal. Assem-
ble bearing cap to cylinder block immediately after
sealant application. Be sure the white paint faces
toward the rear of the engine.
(6) To align the bearing cap, use cap slot, align-
ment dowel, and cap bolts. DO NOT remove excess
material after assembly. DO NOT strike rear cap
more than two times for proper engagement.
(7) Install the rear main bearing cap with cleaned
and oiled cap bolts. Alternately tighten ALL cap bolts
to 115 N´m (85 ft. lbs.) torque.
(8) Install oil pump (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PUMP - INSTALLATION).
(9) Apply MopartGEN II Silicone Rubber Adhe-
sive Sealant, or equivalent, at bearing cap-to-block
joint to provide cap-to-block and oil pan sealing (Fig.
34). Apply enough sealant until a small amount is
squeezed out. Withdraw nozzle and wipe excess seal-
ant off the oil pan seal groove.
(10) Immediately install the oil pan (Refer to 9 -
ENGINE/LUBRICATION/OIL PAN - INSTALLA-
TION).
Fig. 33 Sealant Application to Bearing Cap
1 - MOPAR SILICONE RUBBER ADHESIVE SEALANT SLOTS
2 - MOPARTGASKET MAKER (OR EQUIVALENT)
3 - CAP ALIGNMENT SLOT
4 - REAR MAIN BEARING CAP
Fig. 34 Apply Sealant to Bearing Cap-to-Block Joint
1 - MOPARTGEN II SILICONE RUBBER ADHESIVE SEALANT
NOZZLE TIP
2 - SEALANT APPLIED
3 - CYLINDER BLOCK
4 - REAR MAIN BEARING CAP
9 - 36 ENGINE 3.9LBR/BE
CRANKSHAFT OIL SEAL - REAR (Continued)

HYDRAULIC LIFTERS (CAM IN
BLOCK)
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 thetappet. 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. 38).
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
9 - 38 ENGINE 3.9LBR/BE

PISTON & CONNECTING ROD
DESCRIPTION
The pistons are made of aluminum and have three
ring grooves, the top two grooves are for the compres-
sion rings and the bottom groove is for the oil control
ring. The connecting rods are forged steel and are
coined prior to heat treat. The piston pins are press
fit.
STANDARD PROCEDUREÐPISTON FITTING
Check the cylinder block bore for out-of-round,
taper, scoring, or scuffing.
Check the pistons for taper and elliptical shape
before they are fitted into the cylinder bore (Fig. 39).
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 in.) at
21ÉC (70ÉF).
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).
PISTON MEASUREMENTS CHART
PISTON A DIA = PISTON BORE
SIZE DIAMETER DIAMETER
MIN. MAX. MIN. MAX.
mm
(in.)mm
(in.)mm
(in.)mm (in.)
A99.280 99.294 99.308 99.320
(3.9087) (3.9092) (3.9098) (3.9103)
B99.294 99.306 99.320 99.333
(3.9092) (3.9097) (3.9103) (3.9108)
C99.306 99.319 99.333 99.345
(3.9097) (3.9102) (3.9108) (3.9113)
D99.319 99.332 99.346 99.358
(3.9102) (3.9107) (3.9113) (3.9118)
E99.332 99.344 99.358 99.371
(3.9107) (3.9112) (3.9118) (3.9123)
DESCRIPTION SPECIFICATION
PISTON PIN BORE 25.007 - 25.014 mm
(.9845 - .9848 in.)
RING GROOVE
HEIGHT4.0309 - 4.0538 mm
(OIL RAIL) (.1587 - .1596 in.)
RING GROOVE
HEIGHT2.0294 - 2.0548 mm
(COMPRESSION
RAIL)(.0799 - .0809 in.)
TOTAL FINISHED 594.6 2 grams
WEIGHT (20.974 .0706 ounces)
REMOVAL
(1) Remove the engine from the vehicle (Refer to 9
- ENGINE - REMOVAL).
(2) Remove the cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - REMOVAL).
(3) Remove the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/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 each connecting rod and connecting rod
cap is 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 the
assemblies from the engine, rotate crankshaft so that
Fig. 39 Piston Measurements
1 - 62.230 mm
(2.45 IN.)
9 - 40 ENGINE 3.9LBR/BE

the connecting rod is centered in cylinder bore and at
BDC.Be careful not to nick crankshaft journals.
(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) Be sure that compression ring gaps are stag-
gered so that neither is in line with oil ring rail gap.
(2) Before installing the ring compressor, be sure
the oil ring expander ends are butted and the rail
gaps located properly (Fig. 40).(3) 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).Be sure position of rings
does not change during this operation.
(4) Install connecting rod bolt protectors on rod
bolts. The long protector should be installed on the
numbered side of the connecting rod.
(5) Rotate crankshaft so that the connecting rod
journal is on the center of the cylinder bore. Be sure
connecting rod and cylinder bore number are the
same. Insert rod and piston into cylinder bore and
guide rod over the crankshaft journal.
(6) Tap the piston down in cylinder bore, using a
hammer handle. At the same time, guide connecting
rod into position on crankshaft journal.
(7) The notch, or groove, 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.
(8) Install rod caps. Be sure connecting rod, con-
necting rod cap, and cylinder bore number are the
same. Install nuts on cleaned and oiled rod bolts and
tighten nuts to 61 N´m (45 ft. lbs.) torque.
(9) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
(10) Install the cylinder head (Refer to 9 -
ENGINE/CYLINDER HEAD - INSTALLATION).
(11) Install the engine into the vehicle (Refer to 9 -
ENGINE - INSTALLATION).
PISTON RINGS
STANDARD PROCEDUREÐPISTON RING
FITTING
(1) Measurement of end gaps:
(a) Measure piston ring gap 2 in. from bottom of
cylinder bore. An inverted piston can be used to
push the rings down to ensure positioning rings
squarely in the cylinder bore before measuring.
(b) Insert feeler gauge in the gap. The top com-
pression ring gap should be between 0.254-0.508
mm (0.010-0.020 in.). The second compression ring
gap should be between 0.508-0.762 mm
(0.020-0.030 in.). The oil ring gap should be 0.254-
1.270 mm (0.010-0.050 in.).
(c) Rings with insufficient end gap may be prop-
erly filed to the correct dimension. Rings with
excess gaps should not be used.
(2) Install rings, and confirm ring side clearance:
(a) Install oil rings being careful not to nick or
scratch the piston. Install the oil control rings
according to instructions in the package. It is not
necessary to use a tool to install the upper and
Fig. 40 Proper Ring Installation
1 - OIL RING SPACER GAP
2 - SECOND COMPRESSION RING GAP OIL RING RAIL GAP
(TOP)
3 - OIL RING RAIL GAP (BOTTOM)
4 - TOP COMPRESSION RING GAP
BR/BEENGINE 3.9L 9 - 41
PISTON & CONNECTING ROD (Continued)

DIAGNOSIS AND TESTINGÐENGINE OIL
PRESSURE
(1) Remove oil pressure sending unit.
(2) Install Oil Pressure Line and Gauge Tool
C-3292. Start engine and record pressure. (Refer to 9
- ENGINE - SPECIFICATIONS).
DIAGNOSIS AND TESTINGÐENGINE OIL
LEAKS
Begin with a through visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil-soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
be sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light source.
(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair per service manual instructions.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24km (15 miles), and
repeat previous step.
(5) If the oil leak source is not positively identified
at this time, proceed with the air leak detection test
method as follows:
(6) Disconnect the breather cap to air cleaner hose
at the breather cap end. Cap or plug breather cap
nipple.
(7) Remove the PCV valve from the cylinder head
cover. Cap or plug the PCV valve grommet.
(8) Attach an air hose with pressure gauge and
regulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.
(9) Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provide the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
(10) If the leakage occurs at the rear oil seal area,
refer to the section, Inspection for Rear Seal Area
Leak.
(11) If no leaks are detected, turn off the air sup-
ply and remove the air hose and all plugs and caps.
Install the PCV valve and breather cap hose. Proceed
to next step.(12) Clean the oil off the suspect oil leak area
using a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
OIL
STANDARD PROCEDUREÐENGINE OIL
OIL LEVEL INDICATOR (DIPSTICK)
The engine oil level indicator is located at the right
front of the engine, left of the generator on 3.9L
engines (Fig. 52).
CRANKCASE OIL LEVEL INSPECTION
CAUTION: Do not overfill crankcase with engine oil,
oil foaming and oil pressure loss can result.
To ensure proper lubrication of an engine, the
engine oil must be maintained at an acceptable level.
The acceptable levels are indicated between the ADD
and SAFE marks on the engine oil dipstick.
(1) Position vehicle on level surface.
(2) With engine OFF, allow approximately ten min-
utes for oil to settle to bottom of crankcase, remove
engine oil dipstick.
(3) Wipe dipstick clean.
(4) Install dipstick and verify it is seated in the
tube.
(5) Remove dipstick, with handle held above the
tip, take oil level reading.
Fig. 52 Oil Level Indicator Location
1 - CYLINDER HEAD COVER
2 - ENGINE OIL FILL CAP
3 - DIPSTICK
4 - ENGINE OIL FILTER
5 - FILTER BOSS
BR/BEENGINE 3.9L 9 - 47
LUBRICATION (Continued)

CLEANING
Clean the block and pan gasket surfaces.
Trim or remove excess sealant film in the rear
main cap oil pan gasket groove.DO NOT remove
the sealant inside the rear main cap slots.
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.
INSTALLATION
(1) Clean the block and pan gasket surfaces.
(2) Fabricate four alignment dowels from 5/16 X 1
1/2 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. 55).
(3)
Install the dowels in the cylinder block (Fig. 56).
(4) Apply small amount of MopartSilicone Rubber
Adhesive Sealant, or equivalent, in the corner of the
cap and the cylinder block.
(5) Slide the one-piece gasket over the dowels and
onto the block.
(6) Position the oil pan over the dowels and onto
the gasket.
(7) Install the oil pan bolts. Tighten the bolts to 24
N´m (215 in. lbs.) torque.
(8)
Remove the dowels. Install the remaining oil pan
bolts. Tighten these bolts to 24 N´m (215 in. lbs.) torque.
(9) Lower the engine into the support cushion
brackets and tighten the through-bolt nut to the
proper torque.(10) Install the drain plug. Tighten drain plug to
34 N´m (27 ft. lbs.) torque.
(11) Install the engine to transmission strut.
(12) Install exhaust pipe.
(13) Lower vehicle.
(14) Install dipstick.
(15) Connect the negative cable to the battery.
(16) Fill crankcase with oil to proper level.
OIL PRESSURE SENSOR/
SWITCH
DESCRIPTION
The 2±wire, electrical/mechanical engine oil pres-
sure sensor (sending unit) is located in an engine oil
pressure gallery.
OPERATION
The oil pressure sensor uses two circuits. They are:
²
A signal to the PCM relating to engine oil pressure
²A sensor ground through the PCM's sensor return
The oil pressure sensor returns a voltage signal
back to the PCM relating to engine oil pressure. This
signal is then transferred (bussed) to the instrument
panel on a CCD bus circuit to operate the oil pres-
sure gauge and the check gauges lamp. Ground for
the sensor is provided by the PCM through a low-
noise sensor return.
Fig. 55 Fabrication of Alignment Dowels
1 - 5/16º X 1óº BOLT
2 - DOWEL
3 - SLOT
Fig. 56 Position of Dowels in Cylinder Block
1 - DOWEL
2 - DOWEL
3 - DOWEL
4 - DOWEL
BR/BEENGINE 3.9L 9 - 49
OIL PAN (Continued)

OIL PUMP
REMOVAL
(1) Remove the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL).
(2)
Remove the oil pump from rear main bearing cap.
DISASSEMBLE
(1) Remove the relief valve as follows:
(a) Remove cotter pin. Drill a 3.175 mm (1/8 in.)
hole into the relief valve retainer cap and insert a
self-threading sheet metal screw into cap.
(b) Clamp screw into a vise and while support-
ing oil pump, remove cap by tapping pump body
using a soft hammer. Discard retainer cap and
remove spring and relief valve (Fig. 57).
(2) Remove oil pump cover (Fig. 58).
(3) Remove pump outer rotor and inner rotor with
shaft (Fig. 58).
(4) Wash all parts in a suitable solvent and inspect
carefully for damage or wear.
CLEANING
Use only mild solvents to clean the oil pump. Do
not use any abrasive material to clean the oil pump
housing or rotors.
INSPECTION
Mating surface of the oil pump cover should be
smooth. Replace pump assembly if cover is scratched
or grooved.Lay a straightedge across the pump cover surface
(Fig. 59). If a 0.038 mm (0.0015 in.) feeler gauge can
be inserted between cover and straightedge, pump
assembly should be replaced.
Fig. 57 Oil Pressure Relief Valve
1 - OIL PUMP ASSEMBLY
2 - COTTER PIN
3 - RELIEF VALVE
4 - RETAINER CAP
5 - SPRING
Fig. 58 Oil Pump
1 - INNER ROTOR AND SHAFT
2 - BODY
3 - DISTRIBUTOR DRIVESHAFT (REFERENCE)
4 - COTTER PIN
5 - RETAINER CAP
6 - SPRING
7 - RELIEF VALVE
8 - LARGE CHAMFERED EDGE
9 - BOLT
10 - COVER
11 - OUTER ROTOR
Fig. 59 Checking Oil Pump Cover Flatness
1 - COVER
2 - STRAIGHT EDGE
3 - FEELER GAUGE
9 - 50 ENGINE 3.9LBR/BE