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and/or deterioration.
INSTALLATION
(1) Before installing piston and connecting rod
assemblies into the bore, install the piston rings.
(2) Immerse the piston head and rings in clean engine oil. Position a ring compressor over the piston and rings. Tighten ring compressor. Ensure position of rings do not change during this operation.
(3) Position bearing onto connecting rod. Ensure that hole in bearing shell aligns with hole in connecting rod. Lubricate bearing surface with clean engine oil.
(4) Install Special Tool 8507 Connecting Rod
Guides into connecting rod bolt threads (Fig. 53).
DR PISTON & CONNECTING ROD (Continued)
(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 pistons covered during this operation. Pistons and connect- ing rods must be removed from top of cylinder block. When removing piston and connecting rod assemblies from the engine, rotate crankshaft so the each con- necting rod is centered in cylinder bore.
CAUTION: DO NOT use a number stamp or a punch to mark connecting rods or caps, as damage to connecting rods could occur
NOTE: Connecting rods and bearing caps are not interchangeable and should be marked before removing to ensure correct reassembly.
(4) Mark connecting rod and bearing cap positions
using a permanent ink marker or scribe tool.
CAUTION: Care must be taken not to damage the fractured rod and cap joint face surfaces, as engine damage may occur.
(5) Remove connecting rod cap. Install Special Tool 8507 Connecting Rod Guides into the connecting rod being removed. Remove piston from cylinder bore. Repeat this procedure for each piston being removed.
CAUTION: Care must be taken not to nick crank- shaft journals, as engine damage may occur
(6) Immediately after piston and connecting rod removal, install bearing cap on the mating connect- ing rod to prevent damage to the fractured cap and rod surfaces.
CLEANING
CAUTION: DO NOT use a wire wheel or other abra- sive cleaning devise to clean the pistons or con- necting rods. The pistons have a Moly coating, this coating must not be damaged.
(1) Using a suitable cleaning solvent clean the pis-
tons in warm water and towel dry.
(2) Use a wood or plastic scraper to clean the ring
land grooves.
CAUTION: DO NOT remove the piston pin from the piston and connecting rod assembly.
INSPECTION
Check the connecting rod journal
for excessive wear, taper and scoring (Refer to 9 - ENGINE/EN-
Fig.53PISTONANDCONNECTINGROD
INSTALLATION
1 - “F” TOWARD FRONT OF ENGINE 2 - OIL SLINGER SLOT 3 - RING COMPRESSOR 4 - SPECIAL TOOL 8507
ENGINE - 3.7L
9 - 52
PISTON & CONNECTING ROD (Continued)(5) The pistons are marked on the piston pin bore surface with an raised “F” 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. 54).
DR
† Timing chain and cover. (Refer to 9 - ENGINE/ VALVE TIMING/TIMING BELT / CHAIN COVER(S) - INSTALLATION). † Cylinder head covers (Refer to 9 - ENGINE/ CYLINDER HEAD/CYLINDER HEAD COVER(S) - INSTALLATION). † Oil pan and gasket/windage tray. (Refer to 9 - INSTALLA-
ENGINE/LUBRICATION/OIL PAN - TION).
(11) Fill crankcase with proper engine oil to cor-
rect level.
(12) Connect negative cable to battery.
PISTON RINGS STANDARD PROCEDURE - PISTON RING FITTING
Before reinstalling used rings or installing new
rings, the ring clearances must be checked.
(1) Wipe the cylinder bore clean. (2) Insert the ring in the cylinder bore.
Fig.54PISTONANDCONNECTINGROD
ORIENTATION
1 - MAJOR THRUST SIDE OF PISTON 2 - OIL SLINGER SLOT
NOTE: The ring gap measurement must be made with the ring positioned at least 12mm (0.50 inch.) from bottom of cylinder bore.
(3) Using a piston, to ensure that the ring is squared in the cylinder bore, slide the ring downward into the cylinder.
(4) Using a feeler gauge check the ring end gap (Fig. 55). Replace any rings not within specification.
(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 90°.
(10) Install the following components: † Cylinder head(s). (Refer to 9 - ENGINE/CYLIN-
DER HEAD - INSTALLATION).
Fig.55RingEndGapMeasurement-Typical
1 - FEELER GAUGE
DR PISTON RINGS (Continued)
ENGINE - 3.7L
9 - 53
PISTON RING SIDE CLEARANCE
PISTON RING SPECIFICATION CHART
NOTE: Make sure the piston ring grooves are clean and free of nicks and burrs.
(5) Measure the ring side clearance as shown (Fig. 56)make sure the feeler gauge fits snugly between the ring land and the ring. Replace any ring not within specification.
Fig.56MeasuringPistonRingSideClearance
1 - FEELER GAUGE
(6) Rotate the ring around the piston, the ring
must rotate in the groove with out binding.
Ring Position
Groove
Upper Ring
Clearance .051-.094mm (0.0020- .0037
in.)
Maximum Clearance
0.11mm (0.004 in.)
Intermediate
0.04-0.08mm
0.10mm
Ring
(0.0016-0.0031
(0.004 in.)
Oil Control Ring
(Steel Rails)
in.)
.019-.229mm (.0007-.0090
in.)
Ring Position
Ring Gap
Upper Ring
0.20-0.36mm (0.0079-0.0142
in.)
.25mm
(0.010 in.)
Wear Limit
0.43mm
(0.0017 in.)
Intermediate
0.37-0.63mm
0.74mm
Ring
(0.0146-0.0249
(0.029 in.)
in.)
Oil Control Ring
(Steel Rail)
0.025-0.76mm (0.0099- 0.03
1.55mm (0.061 in.)
in.)
(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: † Oil ring expander. † Upper oil ring side rail. † Lower oil ring side rail. † No. 2 Intermediate piston ring. † No. 1 Upper piston ring.
ENGINE - 3.7L
9 - 54
PISTON RINGS (Continued)DR
(8) Install the oil ring expander. (9) Install upper side rail (Fig. 57) 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. 58).
(11) Install No. 1 upper piston ring using a piston
ring installer (Fig. 58).
(12) Position piston ring end gaps as shown in (Fig. 59). It is important that expander ring gap is at least 45° from the side rail gaps, but not on the pis- ton pin center or on the thrust direction.
Fig.59PistonRingEndGapPosition
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
(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 loosen fan and viscous assembly from
Pins 8346, water pump (Fig. 60).
(7) Remove fan and viscous assembly.
Fig.57SideRail—Installation
1 - SIDE RAIL END
Fig.58UpperandIntermediateRings—Installation VIBRATION DAMPER REMOVAL
(1) Disconnect negative cable from battery. (2) Remove accessory drive belt
(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL).
Fig.60FANASSEMBLY-REMOVAL/ASSEMBLY 1 - SPECIAL TOOL 6958 SPANNER WRENCH WITH ADAPTER PINS 8346
2 - FANDR VIBRATION DAMPER (Continued)
ENGINE - 3.7L
9 - 55
(8) Disconnect electrical connector for fan mounted
inside radiator shroud.
threaded rod’s threads with Mopart Nickel Anti- Seize or (Loctite No. 771).
NOTE: Transmission cooler line snaps into shroud lower right hand corner.
(9) Remove crankshaft damper bolt. (10) Remove damper using Special Tools 8513
Insert and 1026 Three Jaw Puller (Fig. 61).
Fig.62PROPERASSEMBLYMETHODFOR
SPECIALTOOL8512–A
1 - BEARING 2 - NUT 3 - THREADED ROD 4 - BEARING HARDENED SURFACE (FACING NUT) 5 - HARDENED WASHER
(3) Using Special Tool 8512–A, press damper onto
crankshaft (Fig. 63).
Fig.61CRANKSHAFTDAMPER-REMOVAL
1 - SPECIAL TOOL 8513 INSERT 2 - SPECIAL TOOL 1026
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) Align crankshaft damper slot with key in
crankshaft. 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 bearing MUST face the nut). Then the hardened washer slides onto the threaded rod (Fig. 62). Once assembled coat the
Fig.63CrankshaftDamperInstallation
1 - SPECIAL TOOL 8512
(4) Install then tighten crankshaft damper bolt to
175 N·m (130 ft. lbs.).
ENGINE - 3.7L
9 - 56
VIBRATION DAMPER (Continued)(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) Connect electrical connector for shroud fan. (8) Install radiator upper hose. (9) Install accessory drive belt (Refer to 7 - COOL- ING/ACCESSORY DRIVE/DRIVE BELTS - INSTAL- LATION).
(10) Refill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(11) 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 bedplate.
OPERATION
The structural cover provides additional power-
train stiffness and reduces noise and vibration.
REMOVAL
(1) Raise vehicle on hoist. (2) Remove the left hand exhaust pipe from
exhaust manifold.
(3) Loosen the right hand exhaust manifold-to-ex-
haust pipe retaining bolts.
(4) Remove the eight bolts retaining structural
cover (Fig. 64) in the sequence shown.
(5) Pivot the exhaust pipe downward and remove
the structural cover.
DR
INSTALLATION
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 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. 65) to 54 N·m (40 ft. lbs.), then tighten bolts (2) (Fig. 65) and (3) to 54 N·m ( 40
ft. lbs.) in the sequence shown.Fig.65StructuralCover
1 - BOLT 2 - BOLT 3 - BOLT
(5) Install the exhaust pipe on left hand exhaust
manifold.
(6) Tighten
exhaust manifold-to-exhaust retaining bolts to 20–26 N·m (15–20 ft. lbs.).
pipe
Fig.64StructuralCover
1 - BOLT 2 - BOLT 3 - BOLT
DR
FRONT MOUNT REMOVAL
2WD
ENGINE - 3.7L
9 - 57
(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.
(1) Disconnect the negative cable from the battery.
4WD
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
(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 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. 66).
Fig.66ENGINEINSULATORMOUNTS4X4
1 - RH INSULATOR TO AXLE BOLT 2 - NUT 3 - PINION SUPPORT MOUNT 4 - LH INSULATOR MOUNT
5 - LH INSULATOR TO AXLE BOLT 6 - FRONT AXLE 7 - NUT 8 - RH INSULATOR MOUNT
ENGINE - 3.7L
9 - 58
FRONT MOUNT (Continued)DR
(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 (14) Raise the engine far enough to be able to remove the left (Fig. 67) and right (Fig. 68) engine mounts.
Fig.68ENGINEMOUNTSUPPORTBRACKETRH 1 - BOLT 2 - ENGINE MOUNT SUPPORT BRACKET
(4) Tighten the through bolt nuts to 94 N·m (70 ft.
lbs.).
(5) Install the oil drain trough. (6) Install the engine oil filter. (7) Lower the vehicle. (8) Install the viscous fan (Refer to 7 - COOLING/ ENGINE/FAN DRIVE VISCOUS CLUTCH - REMOVAL).
(9) Reconnect the negative battery cable.
4WD
NOTE: For mount to engine block and left engine bracket to front axle bolts, apply MoparT Lock and Seal Adhesive, Medium Strength Threadlocker.
(1) Install the right and left side engine mounts to
the front axle. Torque nuts to 94 N·m (70 ft. lbs.).
(2) Raise the front axle into the frame and install the left and right side through bolts. Torque nuts to 94 N·m (70 ft. lbs.).
(3) Insert the two upper through bolts into the right and left side engine mounts and loose assemble the two nuts onto the through bolts.
(4) Lower the engine until the left and right side engine brackets rest on the through bolts, and the
Fig.67ENGINEMOUNTSUPPORTBRACKET
1 - BOLT 2 - ENGINE MOUNT SUPPORT BRACKET 3 - BOLT
(15) Remove the engine mounts.
INSTALLATION
2WD
NOTE: For mount to engine block and left engine bracket to front axle bolts, apply MoparT Lock and Seal Adhesive, Medium Strength Threadlocker.
(1) Install the right and left side engine mounts to the engine block with (8) bolts. Torque bolts to 54
N·m (40 ft. lbs.).(2) Insert the (2) through bolts into the right and left side engine mounts and loose assemble the two nuts onto the through bolts.
(3) Lower the engine until the through bolts rest
onto the slots in the frame brackets.
DR FRONT MOUNT (Continued)
ENGINE - 3.7L
9 - 59
Fig.69ENGINEINSULATORMOUNTS4X4
1 - RH INSULATOR TO AXLE BOLT 2 - NUT 3 - PINION SUPPORT MOUNT 4 - LH INSULATOR MOUNT
5 - LH INSULATOR TO AXLE BOLT 6 - FRONT AXLE 7 - NUT 8 - RH INSULATOR MOUNT
lower engine bracket through holes align with the engine mounts, and the left engine bracket holes align with the front axle slots (Fig. 69).
(5) Loose assemble the (3) bolts that attach the
front axle to the left engine bracket.
(6) Loose assemble the lower through bolts. (7) Torque the nuts for the (4) through bolts to 101
N·m (75 ft. lbs.).
(8) Torque the (3) bolts that attach the front axle
to the left engine bracket to 101 N·m (75 ft. lbs.).
(9) Install the oil drain trough. (10) Install the engine oil filter. (11) Install the front crossmember. (12) Install the skid plate. (13) Lower the vehicle. (14) Install the viscous fan (Refer to 7 - COOL- ING/ENGINE/FAN DRIVE VISCOUS CLUTCH - REMOVAL).
(15) Reconnect the negative battery cable.
9 - 60
ENGINE - 3.7L
REAR MOUNT REMOVAL
(1) Raise the vehicle on a hoist. (2) Using a suitable jack, support transmission. (3) Remove the nuts from the transmission mount
(Fig. 70).
Fig.70TRANSMISSIONMOUNT
1 - MOUNT 2 - CROSSMEMBER 3 - NUT 4 - BOLT
(4) Remove the two bolts that attach the transmis-
sion mount to the engine bracket.
(5) Raise the transmission enough to remove the
mount from the crossmember.
(6) Remove the mount.
INSTALLATION
NOTE: Threadlocking compound must be applied to the bolts before installation.
DR
(1) Install the two bolts that attach the transmis-
sion mount to the transmission bracket.
(2) Torque the bolts to 61N·m (45 ft.lbs.) torque. (3) Lower the transmission so the transmission mount rests on the crossmember, and the studs of the transmission mount are aligned in the slots in the crossmember.
(4) Install the nuts onto the transmission mount
studs through the crossmember access slot. (5) Torque the nuts to 54N·m (40 ft. lbs.).
LUBRICATION DESCRIPTION
The lubrication system is a full flow filtration pres-
sure feed type.
OPERATION
Oil from the oil pan is pumped by a gerotor type oil pump directly mounted to the crankshaft nose. Oil pressure is controlled by a relief valve mounted inside the oil pump housing. For lubrication flow refer to (Fig. 71)
The camshaft exhaust valve lobes and rocker arms are lubricated through a small hole in the rocker arm; oil flows through the lash adjuster then through the rocker arm and onto the camshaft lobe. Due to the orientation of the rocker arm, the camshaft intake lobes are not lubed in the same manner as the exhaust lobes. The intake lobes are lubed through internal passages in the camshaft. Oil flows through a bore in the number 3 camshaft bearing bore, and as the camshaft turns, a hole in the camshaft aligns with the hole in the camshaft bore allowing engine oil to enter the camshaft tube. The oil then exits through 1.6mm (0.063 in.) holes drilled into the intake lobes, lubricating the lobes and the rocker arms.
DR LUBRICATION (Continued)
ENGINE - 3.7L
9 - 61
ENGINE LUBRICATION FLOW CHART - BLOCK: TABLE 1
FROM
TO
Oil Pickup Tube Oil Pump Oil Filter Block Main Oil Gallery
Crankshaft Main Journals Crankshaft Number One Main Journal
Left Cylinder Head
Right Cylinder Head
Oil Pump Oil Filter Block Main Oil Gallery 1. Crankshaft Main Journal 2. Left Cylinder Head* 3. Right Cylinder Head* 4. Counterbalance Shaft Rear Journal Crankshaft Rod Journals 1. Front Timing Chain Idler Shaft 2. Counterbalance Shaft - Front Journal 3. Both Secondary Chain Tensioners Refer to Engine Lubrication Flow Chart - Cylinder Heads: Table 2
Refer to Engine Lubrication Flow Chart - Cylinder Heads: Table 2* The cylinder head gaskets have an oil restricter to control oil flow to the cylinder heads
ENGINE LUBRICATION FLOW CHART - CYLINDER HEADS: TABLE 2
FROM
Cylinder Head Oil Port (in bolt hole) Main Oil Gallery (drilled through head from rear to front)
TO
Diagonal Cross Drilling to Main Oil Gallery 1. Base of Camshaft Towers
2. Lash Adjuster Towers Vertical Drilling Through Tower to Camshaft Bearings** Base of Camshaft Towers Lash Adjuster Towers Diagonal Drillings to Hydraulic Lash Adjuster Pockets ** The number three camshaft bearing journal feeds oil into the hollow camshaft tubes. Oil is routed to the intake lobes, which have oil passages drilled into them to lubricate the rocker arms.
ENGINE - 3.7L
9 - 62
LUBRICATION (Continued)DR
Fig.71LUBRICATIONOILFLOW
1 - OIL FLOW TO RIGHT CYLINDER HEAD 2 - CYLINDER BLOCK MAIN OIL GALLERY 3 - LEFT CYLINDER HEAD OIL GALLERY 4 - OIL FLOW TO BOTH SECONDARY TENSIONERS 5 - OIL FLOW TO LEFT CYLINDER HEAD 6 - OIL PRESSURE SENSOR LOCATION
7 - OIL FLOW TO COUNTER BALANCE SHAFT 8 - OIL PUMP OUTLET TO CYLINDER BLOCK 9 - OIL PUMP 10 - OIL FLOW TO CRANKSHAFT MAIN JOURNALS 11 - CRANKSHAFT MAIN BEARING JOURNALS 12 - RIGHT CYLINDER HEAD OIL GALLERY
DR LUBRICATION (Continued) DIAGNOSIS AND TESTING
Begin with a thorough visual
DIAGNOSIS AND TESTING—ENGINE OIL LEAK 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 make sure the dye is thoroughly mixed as indicated with a bright yellow color under a black light.
(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 24 km (15 miles), and repeat inspection. If the oil leak source is not pos- itively identified at this time, proceed with the air leak detection test method.
Air Leak Detection Test Method
(1) Disconnect the breather cap to air cleaner hose at the breather cap end. Cap or plug breather cap nipple.
(2) Remove the PCV valve from the cylinder head
cover. Cap or plug the PCV valve grommet.
(3) 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.
(4) 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.(5) If the leakage occurs at the rear oil seal area, refer to the section, Inspection for Rear Seal Area Leak.
(6) If no leaks are detected, turn off the air supply and remove the air hose and all plugs and caps. Install the PCV valve and breather cap hose.
ENGINE - 3.7L
9 - 63
(7) 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.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the source of an oil leak in the rear seal area of the engine, a more involved inspection is necessary. The following steps should be followed to help pinpoint the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery. (2) Raise the vehicle. (3) Remove torque converter or clutch housing cover and inspect rear of block for evidence of oil. Use a black light to check for the oil leak:
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down, possible causes are a porous block, distributor seal, camshaft bore cup plugs oil galley pipe plugs, oil filter runoff, and main bearing cap to cylinder block mating surfaces. (4) If no leaks are detected, pressurize the crank- case as outlined in the, Inspection (Engine oil Leaks in general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the crankshaft and watch for leakage. If a leak is detected between the crankshaft and seal while slowly turning the crankshaft, it is possible the crankshaft seal surface is damaged. The seal area on the crankshaft could have minor nicks or scratches that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft polishing is necessary to remove minor nicks and scratches. The crankshaft seal flange is especially machined to complement the function of the rear oil seal.
(6) For bubbles that remain steady with shaft rotation, no further inspection can be done until dis- assembled.
ENGINE - 3.7L
9 - 64
LUBRICATION (Continued) DIAGNOSIS AND TESTING - CHECKING ENGINE OIL PRESSURE(1) Remove oil pressure sending unit (Fig. 72)and
install gauge assembly C-3292.
Fig.72OILPRESSURESENDINGUNIT-TYPICAL 1 - BELT 2 - OIL PRESSURE SENSOR 3 - OIL FILTER 4 - ELEC. CONNECTOR
(2) Run engine until thermostat opens. (3) Oil Pressure: † Curb Idle–25 kPa (4 psi) minimum † 3000 rpm–170 - 758 kPa (25 - 110 psi) (4) If oil pressure is 0 at idle, shut off engine. Check for a clogged oil pick-up screen or a pressure relief valve stuck open.
DIAGNOSIS AND TESTING - REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the source of an oil leak in the rear seal area of the engine, a more involved inspection is necessary. The
DR
following steps should be followed to help pinpoint the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery. (2) Raise the vehicle. (3) Remove torque converter or clutch housing cover and inspect rear of block for evidence of oil. Use a black light to check for the oil leak:
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down, possible causes are a porous block, camshaft bore cup plugs, oil galley pipe plugs, oil filter runoff, and main bearing cap to cylinder block mating sur- faces. See Engine, for proper repair procedures of these items. (4) If no leaks are detected, pressurized the crank- case as outlined in the section, Inspection (Engine oil Leaks in general)
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the crankshaft and watch for leakage. If a leak is detected between the crankshaft and seal while slowly turning the crankshaft, it is possible the crankshaft seal surface is damaged. The seal area on the crankshaft could have minor nicks or scratches that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft polishing is necessary to remove minor nicks or scratches. The crankshaft seal flange is specially machined to complement the function of the rear oil seal.
(6) For bubbles that remain steady with shaft rotation, no further inspection can be done until dis- assembled. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING), under the Oil Leak row, for components inspections on possible causes and corrections.
(7) After the oil leak root cause and appropriate corrective action have been identified, (Refer to 9 - ENGINE/ENGINE OIL SEAL - REAR - REMOVAL).
BLOCK/CRANKSHAFT
DR
OIL PAN DESCRIPTION
The engine oil pan is made of laminated steel and has a single plane sealing surface. The sandwich style oil pan gasket has an integrated windage tray and steel carrier (Fig. 73). The sealing area of the gasket is molded with rubber and is designed to be reused as long as the gasket is not cut, torn or ripped.
Fig.73OilPanAndGasket
1 - OIL PAN 2 - WINDAGE TRAY AND INTEGRATED OIL PAN GASKET
REMOVAL
(1) Disconnect the negative battery cable. (2) Install engine support fixture special tool #
8534. Do not raise engine at this time.
(3) Loosen both left and right side engine mount
through bolts. Do not remove bolts.
(4) Remove the structural dust cover, if equipped. (5) Drain engine oil. (6) Remove the front crossmember(Refer to 13 - FRAME & BUMPERS/FRAME/FRONT CROSS- MEMBER - REMOVAL).
CAUTION: Only raise the engine enough to provide clearance for oil pan removal. Check for proper
ENGINE - 3.7L
9 - 65
clearance at fan shroud to fan and cowl to intake manifold.
(7) Raise engine using special tool # 8534 to pro-
vide clearance to remove oil pan.
NOTE: Do not pry on oil pan or oil pan gasket. Gas- ket is integral to engine windage tray and does not come out with oil pan.
(8) Remove the oil pan mounting bolts and oil pan. (9) Unbolt oil pump pickup tube and remove tube. (10) Inspect the integral windage tray (Fig. 74)
and gasket and replace as needed.
Fig.74OilPanAndGasket
1 - OIL PAN 2 - WINDAGE TRAY AND INTEGRATED OIL PAN GASKET
CLEANING
(1) Clean oil pan in solvent and wipe dry with a
clean cloth.
(2) Clean the oil pan gasket surface. DO NOT use a grinder wheel or other abrasive tool to clean seal- ing surface.
(3) Clean oil screen and tube thoroughly in clean
solvent.
9 - 66
ENGINE - 3.7L OIL PAN (Continued) INSPECTIONDR
(1) Inspect oil drain plug and plug hole for
stripped or damaged threads. Repair as necessary.
(2) Inspect the oil pan mounting flange for bends
or distortion. Straighten flange, if necessary.
INSTALLATION
(1) Clean the oil pan gasket mating surface of the
bedplate and oil pan.
(2) Inspect integrated oil pan gasket, and replace
(3) Position the integrated oil pan gasket/windage
as necessary.
tray assembly.
(4) Install the oil pickup tube (5) Install the mounting bolt and nuts. Tighten
nuts to 28 N·m (20 ft. lbs.).
(6) Position the oil pan and install the mounting bolts. Tighten the mounting bolts to 15 N·m (11 ft. lbs.) in the sequence shown (Fig. 75).
(7) Lower the engine into mounts using special
tool # 8534.
(8) Install both the left and right side engine mount through bolts. Tighten the nuts to 68 N·m (50
ft. lbs.).(9) Remove special tool # 8534. (10) Install structural dust cover, if equipped. (11) Install the front crossmember(Refer to 13 - FRAME & BUMPERS/FRAME/FRONT CROSS- MEMBER - INSTALLATION).
(12) Fill engine oil. (13) Reconnect the negative battery cable. (14) Start engine and check for leaks.
OIL PRESSURE SENSOR/ SWITCH DESCRIPTION
The 3–wire, solid-state engine oil pressure sensor (sending unit) is located in an engine oil pressure gallery.
OPERATION
The oil pressure sensor uses three circuits. They
are:
Fig.75OilPanMountingBoltSequence
† A 5–volt power supply from the Powertrain Con- trol Module (PCM) † A sensor ground through the PCM’s sensor return† A signal to the PCM relating to engine oil pres- sure The oil pressure sensor has a 3–wire electrical function very much like the Manifold Absolute Pres- sure (MAP) sensor. Meaning different pressures relate to different output voltages.
A 5–volt supply is sent to the sensor from the PCM to power up the sensor. The sensor returns a voltage signal back to the PCM relating to engine oil pres- sure. This signal is then transferred (bussed) to the instrument panel on either a CCD or PCI bus circuit (depending on vehicle line) to operate the oil pressure gauge and the check gauges lamp. Ground for the sensor is provided by the PCM through a low-noise sensor return.
DR OIL PRESSURE SENSOR/SWITCH (Continued) REMOVAL
DISASSEMBLY
ENGINE - 3.7L
9 - 67
(1) Disconnect the negative cable from the battery. (2) Raise vehicle on hoist. (3) Remove front splash shield. (4) Disconnect oil pressure sender wire (Fig. 76). (5) Remove the pressure sender (Fig. 76).
Fig.76OILPRESSURESENDINGUNIT
1 - BELT 2 - OIL PRESSURE SENSOR 3 - OIL FILTER 4 - ELEC. CONNECTOR
INSTALLATION
(1) Install oil pressure sender. (2) Connect oil pressure sender wire. (3) Install front splash shield. (4) Lower vehicle. (5) Connect the negative battery cable.
OIL PUMP REMOVAL
(1) Remove the oil pan and pick-up tube (Refer to 9 - ENGINE/LUBRICATION/OIL PAN - REMOVAL). (2) Remove the timing chain cover (Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT / CHAIN COVER(S) - REMOVAL).
(3) Remove the timing chains and tensioners (Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT/CHAIN AND SPROCKETS - REMOVAL).
(4) Remove the four bolts, primary timing chain
tensioner and the oil pump.
(1) Remove oil pump cover screws and lift off cover
plate.
(2) Remove pump inner and outer rotors.
NOTE: Once the oil pressure relief valve, cup plug, and pin are removed, the pump assembly must be replaced.
(3) If it is necessary to remove the pressure relief valve, drive the roll pin from pump housing and remove cup plug, spring and valve.
INSPECTION
CAUTION: Oil pump pressure relief valve and spring should not be removed from the oil pump. If these are disassembled and or removed from the pump the entire oil pump assem- bly must be replaced.
components
(1) Clean all parts thoroughly. Mating surface of the oil pump housing should be smooth. If the pump cover is scratched or grooved the oil pump assembly should be replaced.
(2) Lay a straight edge across the pump cover sur- face (Fig. 77). If a 0.025 mm (0.001 in.) feeler gauge can be inserted between the cover and the straight edge the oil pump assembly should be replaced.
(3) Measure the thickness of the outer rotor (Fig. 78). If the outer rotor thickness measures at 12.005
mm (0.472 in.) or less the oil pump assembly must be replaced.(4) Measure the diameter of the outer rotor. If the outer rotor diameter measures at 85.925 mm (3.382
in.) or less the oil pump assembly must be replaced. (5) Measure the thickness of the inner rotor (Fig. 79). If the inner rotor thickness measures at 12.005
mm (0.472 in.) or less then the oil pump assembly must be replaced.(6) Slide outer rotor into the body of the oil pump. Press the outer rotor to one side of the oil pump body and measure clearance between the outer rotor and the body (Fig. 80). If the measurement is 0.235mm (0.009 in.) or more the oil pump assembly must be replaced.
(7) Install the inner rotor in the into the oil pump body. Measure the clearance between the inner and outer rotors (Fig. 81). If the clearance between the rotors is .150 mm (0.006 in.) or more the oil pump assembly must be replaced.
(8) Place a straight edge across the body of the oil pump (between the bolt holes), if a feeler gauge of .095 mm (0.0038 in.) or greater can be inserted between the straightedge and the rotors, the pump must be replaced (Fig. 82).
ENGINE - 3.7L
9 - 68
OIL PUMP (Continued)NOTE: The 3.7 Oil pump is released as an assem- bly. There are no DaimlerChrysler part numbers for Sub-Assembly components. the oil pump is not functioning or out of specification it must be replaced as an assembly.
In the event
DR
Fig.79MeasuringInnerRotorThickness
Fig.77CheckingOilPumpCoverFlatness
1 - STRAIGHT EDGE 2 - FEELER GAUGE 3 - OIL PUMP COVER
Fig.80MeasuringOuterRotorClearance
1 - FEELER GAUGE 2 - OUTER ROTOR
INSTALLATION
Fig.78MeasuringOuterRotorThickness
ASSEMBLY
(1) Wash all parts in a suitable solvent and inspect
carefully for damage or wear.
(2) Install inner and outer rotors (3) Install oil pump cover plate and install cover
bolts and tighten them to 12 N·m (105 in. lbs.).
(4) Prime oil pump before installation by filling
rotor cavity with engine oil.
(5) If oil pressure is low and pump is within spec- ifications, inspect for worn engine bearings or other causes for oil pressure loss.
(1) Position the oil pump onto the crankshaft and
install one oil pump retaining bolts.
(2) Position the primary timing chain tensioner
and install three retaining bolts.
(3) Tighten the oil pump and primary timing chain tensioner retaining bolts to 28 N·m (250 in. lbs.) in the sequence shown (Fig. 83).
(4) Install the secondary timing chain tensioners and timing chains (Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT/CHAIN AND SPROCKETS - INSTALLATION).
(5) Install the timing chain cover (Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT / CHAIN COVER(S) - INSTALLATION).
DR OIL PUMP (Continued)
ENGINE - 3.7L
9 - 69
Fig.81MeasuringClearanceBetweenRotors
1 - OUTER ROTOR 2 - FEELER GAUGE 3 - INNER ROTOR
Fig.83OilPumpAndPrimaryTimingChain
TensionerTighteningSequence
(2) Using a suitable oil filter wrench loosen filter. (3) Rotate the oil filter counterclockwise (Fig. 84)
to remove it from the cylinder block oil filter boss.
Fig.82MeasuringClearanceOverRotors
1 - STRAIGHT EDGE 2 - FEELER GAUGE
(6) Install the pick-up tube and oil pan (Refer to 9
- ENGINE/LUBRICATION/OIL PAN - INSTALLA- TION).OIL FILTER REMOVAL
All engines are equipped with a high quality full- flow, disposable type oil filter. DaimlerChrysler Cor- poration recommends a Mopart or equivalent oil filter be used.
(1) Position a drain pan under the oil filter.
Fig.84OILFILTER
1 - ENGINE OIL FILTER
(4) When filter separates from cylinder block oil filter boss, tip gasket end upward to minimize oil spill. Remove filter from vehicle.
ENGINE - 3.7L
9 - 70
OIL FILTER (Continued)NOTE: Make sure filter gasket was removed with fil- ter.
(5) With a wiping cloth, clean the gasket sealing
surface of oil and grime.
INSTALLATION
(1) Lightly lubricate oil filter gasket with engine
oil.
(2) Thread filter onto adapter nipple. When gasket makes contact with sealing surface, (Fig. 85) hand tighten filter one full turn, do not over tighten.
(3) Add oil, verify crankcase oil
level and start
engine. Inspect for oil leaks.
DR
API SERVICE GRADE CERTIFIED
Use an engine oil that is API Service Grade Certi- fied. MOPARt provides engine oils that conform to this service grade.
SAE VISCOSITY
An SAE viscosity grade is used to specify the vis- cosity of engine oil. Use only engine oils with multi- ple viscosities such as 5W-30 or 10W-30 in the 4.7L engines. These are specified with a dual SAE viscos- ity grade which indicates the cold-to-hot temperature viscosity range. Select an engine oil that is best suited to your particular temperature range and vari- ation (Fig. 86).
Fig.85OilFilterSealingSurface-Typical
1 - SEALING SURFACE 2 - RUBBER GASKET 3 - OIL FILTER
OIL STANDARD PROCEDURE - ENGINE OIL SERVICE
WARNING: NEW OR USED ENGINE OIL CAN BE IRRITATING TO THE SKIN. AVOID PROLONGED OR REPEATED SKIN CONTACT WITH ENGINE OIL. CONTAMINANTS IN USED ENGINE OIL, CAUSED BY INTERNAL COMBUSTION, CAN BE HAZARDOUS TO YOUR HEALTH. THOROUGHLY WASH EXPOSED SKIN WITH SOAP AND WATER. DO NOT WASH SKIN WITH GASOLINE, DIESEL FUEL, THINNER, OR SOLVENTS, HEALTH PROBLEMS CAN RESULT. DO NOT POLLUTE, DISPOSE OF USED ENGINE OIL PROPERLY.
ENGINE OIL SPECIFICATION
CAUTION: Do not use non-detergent or straight mineral oil when adding or changing crankcase lubricant. Engine failure can result.
Fig.86TEMPERATURE/ENGINEOILVISCOSITY-
4.7LENGINE
ENERGY CONSERVING OIL
An Energy Conserving type oil is recommended for gasoline engines. The designation of ENERGY CON- SERVING is located on the label of an engine oil con- tainer.
CONTAINER IDENTIFICATION
Standard engine oil identification notations have been adopted to aid in the proper selection of engine oil. The identifying notations are located on the label of engine oil plastic bottles and the top of engine oil cans (Fig. 87).
Fig.87EngineoilContainerStandardNotations
DR OIL (Continued) OIL LEVEL INDICATOR (DIPSTICK)
The engine oil level indicator is located at the right
rear of the engine on the 4.7L engines. (Fig. 88).
Fig.88ENGINEOILDIPSTICK4.7LENGINE
1 - TRANSMISSION DIPSTICK 2 - ENGINE OIL DIPSTICK 3 - ENGINE OIL FILL CAP
CRANKCASE OIL LEVEL INSPECTION
CAUTION: Do not overfill crankcase with engine oil, pressure loss or oil foaming can result.
Inspect engine oil level approximately every 800
kilometers (500 miles). Unless the engine has exhib- ited loss of oil pressure, run the engine for about five minutes before checking oil level. Checking engine oil level on a cold engine is not accurate.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
(5) Remove dipstick, with handle held above the
tip, take oil level reading.
(6) Add oil only if level is below the ADD mark on
tube.
dipstick.
ENGINE - 3.7L
9 - 71
ENGINE OIL CHANGE
Change engine oil at mileage and time intervals
described in Maintenance Schedules.
Run engine until achieving normal operating tem-
perature.
engine off.
drain.
(1) Position the vehicle on a level surface and turn
(2) Hoist and support vehicle on safety stands. (3) Remove oil fill cap. (4) Place a suitable drain pan under crankcase
(5) Remove drain plug from crankcase and allow oil to drain into pan. Inspect drain plug threads for stretching or other damage. Replace drain plug if damaged.
(6) Install drain plug in crankcase. (7) Lower vehicle and fill crankcase with specified type and amount of engine oil described in this sec- tion.
(8) Install oil fill cap. (9) Start engine and inspect for leaks. (10) Stop engine and inspect oil level.
USED ENGINE OIL DISPOSAL
Care should be exercised when disposing used engine oil after it has been drained from a vehicle engine. Refer to the WARNING at beginning of this section.
INTAKE MANIFOLD DESCRIPTION
The intake manifold (Fig. 89) is made of a compos- ite material and features 300 mm (11.811 in.) long runners which maximizes low end torque. The intake manifold uses single plane sealing which consist of six individual press in place port gaskets to prevent leaks. The throttle body attaches directly to the intake manifold. Eight studs and two bolts are used to fasten the intake to the head.
DIAGNOSIS AND TESTING - INTAKE MANIFOLD LEAKS
An intake manifold air leak is characterized by lower than normal manifold vacuum. Also, one or more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE ENGINE IS OPERATING. DO NOT STAND IN A DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE PULLEYS, BELTS OR THE FAN. DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
ENGINE - 3.7L
9 - 72
INTAKE MANIFOLD (Continued)DR
(8) Disconnect left and right radio suppressor straps. (9) Disconnect and remove ignition coil towers. (10) Remove top oil dipstick tube retaining bolt
and ground strap.
(11) Bleed fuel system. Refer to FUEL SYSTEM. (12) Remove fuel rail. (13) Remove throttle body assembly and mounting
bracket.
(14) Drain cooling system below coolant tempera-
ture level. Refer to COOLING SYSTEM.
(15) Remove the heater hoses from the engine
front cover and the heater core.
(16) Unclip and remove heater hoses and tubes
from intake manifold.
FUEL SYSTEM.
(17) Remove coolant temperature sensor. Refer to
(18) Remove intake manifold retaining fasteners in
reverse order of tightening sequence.
(19) Remove intake manifold.
INSTALLATION
(1) Install intake manifold gaskets. (2) Install intake manifold. (3) Install
intake manifold retaining bolts and tighten in sequence shown in to 12 N·m (105 in. lbs.) (Fig. 90).
Fig.89IntakeManifold
1 - THROTTLE BODY 2 - INTAKE MANIFOLD 3 - INTAKE PORT GASKETS
(2) Spray a small stream of water (spray bottle) at
the suspected leak area.
(3) If engine RPM’S change, the area of the sus-
pected leak has been found.
(4) Repair as required.
REMOVAL
(1) Disconnect negative cable from battery. (2) Remove resonator assembly and air inlet hose. (3) Disconnect throttle and speed control cables. (4) Disconnect electrical connectors for the follow- ing components: Refer to FUEL SYSTEM for compo- nent locations.
† Manifold Absolute Pressure (MAP) Sensor † Intake Air Temperature (IAT) Sensor † Throttle Position (TPS) Sensor † Coolant Temperature (CTS) Sensor † Idle Air Control (IAC) Motor (5) Disconnect vapor purge hose, brake booster hose, speed control servo hose, positive crankcase ventilation (PCV) hose.
(6) Disconnect generator electrical connections. (7) Disconnect air conditioning compressor electri-
cal connections.
Fig.90IntakeManifoldTighteningSequence
(4) Install left and right radio suppressor straps. (5) Install throttle body assembly. (6) Connect throttle cable and speed control cable
to throttle body.
(7) Install fuel rail. (8) Install ignition coil towers.
DR INTAKE MANIFOLD (Continued)
(9) Position and install heater hoses and tubes
onto intake manifold.
engine front cover.
(10) Install the heater hoses to the heater core and
(11) Connect electrical connectors for the following components: † Manifold Absolute Pressure (MAP) Sensor † Intake Air Temperature (IAT) Sensor † Throttle Position (TPS) Sensor † Coolant Temperature (CTS) Sensor † Idle Air Control (IAC) Motor † Ignition coil towers † Fuel injectors (12) Install top oil dipstick tube retaining bolt and
ground strap.
(13) Connect generator electrical connections. (14) Connect Vapor purge hose, Brake booster hose, Speed control servo hose, Positive crankcase ventilation (PCV) hose.
(15) Fill cooling system. (16) Install resonator assembly and air inlet hose. (17) Connect negative cable to battery.
EXHAUST MANIFOLD DESCRIPTION
The exhaust manifolds (Fig. 91) are log style with a patented flow enhancing design to maximize perfor- mance. The exhaust manifolds are made of high sili- con molybdenum cast iron. A perforated core graphite
Fig.91EXHAUSTMANIFOLDS
1 - LEFT SIDE EXHAUST MANIFOLD 2 - RIGHT SIDE EXHAUST MANIFOLD
ENGINE - 3.7L
9 - 73
exhaust manifold gasket is used to improve sealing to the cylinder head. The exhaust manifolds are cov- ered by a three layer laminated heat shield for ther- mal protection and noise reduction. The heat shields (Fig. 92) are fastened with a torque prevailing nut that is backed off slightly to allow for the thermal expansion of the exhaust manifold.
Fig.92ExhaustManifoldHeatShields
1 - RIGHT SIDE EXHAUST MANIFOLD HEAT SHIELD 2 - RIGHT SIDE EXHAUST MANIFOLD FLANGE 3 - LEFT SIDE EXHAUST MANIFOLD HEAT SHIELD 4 - LEFT SIDE EXHAUST MANIFOLD FLANGE
REMOVAL
RIGHT EXHAUST MANIFOLD
(1) Disconnect the negative cable from the battery. (2) Raise and support the vehicle. (3) Remove the bolts and nuts attaching the
exhaust pipe to the engine exhaust manifold.
(4) Lower the vehicle. (5) Remove the exhaust heat shield (Fig. 93). (6) Remove bolts, nuts and washers attaching
manifold to cylinder head.
(7) Remove manifold and gasket from the cylinder
head.
ENGINE - 3.7L
9 - 74
EXHAUST MANIFOLD (Continued)DR
Fig.93ExhaustManifoldRight
Fig.94ExhaustManifoldleft
1 - HEAT SHIELD 2 - NUTS 3 - MANIFOLD FLANGE
LEFT EXHAUST MANIFOLD
(1) Disconnect the negative cable from the battery. (2) Raise and support the vehicle. (3) Remove the bolts and nuts attaching the
exhaust pipe to the engine exhaust manifold.
(4) Lower the vehicle. (5) Remove the exhaust heat shields (Fig. 94). (6) Remove bolts, nuts and washers attaching
manifold to cylinder head.
(7) Remove manifold and gasket from the cylinder
head.
INSTALLATION
RIGHT EXHAUST MANIFOLD
CAUTION: If the studs came out with the nuts when removing the engine exhaust manifold, install new studs. Apply sealer on the coarse thread ends. Water leaks may develop at the studs if this precau- tion is not taken.
(1) Position the engine exhaust manifold and gas- ket on the two studs located on the cylinder head. Install conical washers and nuts on these studs.
(2) Install remaining conical washers. Starting at the center arm and working outward, tighten the bolts and nuts to 25 N·m (18 ft. lbs.) torque.
(3) Install the exhaust heat shields. (4) Raise and support the vehicle.
1 - HEAT SHIELD 2 - NUTS 3 - MANIFOLD FLANGE
CAUTION: Over tightening heat shield fasteners, may cause shield to distort and/or crack.
(5) Assemble exhaust pipe to manifold and secure with bolts, nuts and retainers. Tighten the bolts and nuts to 34 N·m (25 ft. lbs.) torque.
LEFT EXHAUST MANIFOLD
CAUTION: If the studs came out with the nuts when removing the engine exhaust manifold, install new studs. Apply sealer on the coarse thread ends. Water leaks may develop at the studs if this precau- tion is not taken.
(1) Position the engine exhaust manifold and gas- ket on the two studs located on the cylinder head. Install conical washers and nuts on these studs.
(2) Install remaining conical washers. Starting at the center arm and working outward, tighten the bolts and nuts to 25 N·m (18 ft. lbs.) torque.
(3) Install the exhaust heat shields. (4) Raise and support the vehicle.
CAUTION: Over tightening heat shield fasteners, may cause shield to distort and/or crack.
(5) Assemble exhaust pipe to manifold and secure with bolts, nuts and retainers. Tighten the bolts and nuts to 34 N·m (25 ft. lbs.) torque.
DR
VALVE TIMING DESCRIPTION
The timing drive system has been designed to pro- vide quiet performance and reliability to support a non-free wheeling engine. Specifically the intake valves are non-free wheeling and can be easily dam- aged with forceful engine rotation if camshaft-to- crankshaft timing is incorrect. The timing drive system consists of a primary chain, two secondary timing chain drives (Fig. 95) and a counterbalance shaft drive.
OPERATION
The primary timing chain is a single inverted tooth chain type. The primary chain drives the large 50
ENGINE - 3.7L
9 - 75
tooth idler sprocket directly from a 25 tooth crank- shaft sprocket. Primary chain motion is controlled by a pivoting leaf spring tensioner arm and a fixed guide. The arm and the guide both use nylon plastic wear faces for low friction and long wear. The pri- mary chain receives oil splash lubrication from the secondary chain drive and designed oil pump leak- age. The idler sprocket assembly connects the pri- mary chain drive, secondary chain drives, and the counterbalance shaft. The idler sprocket assembly consists of two integral 26 tooth sprockets a 50 tooth sprocket and a helical gear that is press-fit to the assembly. The spline joint for the 50 tooth sprocket is a non – serviceable press fit anti rattle type. A spiral ring is installed on the outboard side of the 50 tooth sprocket to prevent spline disengagement. The idler sprocket assembly spins on a stationary idler shaft.
Fig.95TimingDriveSystem
1 - RIGHT CAMSHAFT SPROCKET AND SECONDARY CHAIN 2 - SECONDARY TIMING CHAIN TENSIONER (LEFT AND RIGHT SIDE NOT INTERCHANGEABLE) 3 - SECONDARY TENSIONER ARM 4 - LEFT CAMSHAFT SPROCKET AND SECONDARY CHAIN 5 - CHAIN GUIDE (LEFT AND RIGHT SIDE ARE NOT INTERCHANGEABLE)
6 - PRIMARY CHAIN 7 - IDLER SPROCKET 8 - CRANKSHAFT SPROCKET 9 - PRIMARY CHAIN TENSIONER
ENGINE - 3.7L
9 - 76
VALVE TIMING (Continued)The idler shaft is a light press-fit into the cylinder block. A large washer on the idler shaft bolt and the rear flange of the idler shaft are used to control sprocket thrust movement. Pressurized oil is routed through the center of the idler shaft to provide lubri- cation for the two bushings used in the idler sprocket assembly.
There are two secondary drive chains, both are roller type, one to drive the camshaft in each SOHC cylinder head. There are no shaft speed changes in the secondary chain drive system. Each secondary chain drives a 26 tooth cam sprocket directly from the 26 tooth sprocket on the idler sprocket assembly. A fixed chain guide and a hydraulic oil damped ten- sioner are used to maintain tension in each second- ary chain system. The hydraulic tensioners for the secondary chain systems are fed pressurized oil from oil reservoir pockets in the block. Each tensioner incorporates a controlled leak path through a device known as a vent disc located in the nose of the piston to manage chain loads. Each tensioner also has a mechanical ratchet system that limits chain slack if the tensioner piston bleeds down after engine shut down. The tensioner arms and guides also utilize nylon wear faces for low friction and long wear. The secondary timing chains receive lubrication from a small orifice in the tensioners. This orifice is pro- tected from clogging by a fine mesh screen which is located on the back of the hydraulic tensioners.
STANDARD PROCEDURE
MEASURING TIMING CHAIN WEAR
NOTE: This procedure must be performed with the timing chain cover removed.
(1) Remove the timing chain cover. Refer to Timing
Chain Cover in this section for procedure.
(2) To determine if the secondary timing chains are worn, rotate the engine clockwise until maximum tensioner piston extension is obtained. Measure the distance between the secondary timing chain ten- sioner housing and the step ledge on the piston. The measurement at point (A) must be less than 15mm (.5906 inches).
(3) If the measurement exceeds the specification the secondary timing chains are worn and require replacement. Refer to Timing Chain and Sprockets in this section for procedure.
SERVICE PROCEDURE - TIMING VERIFICATION
CAUTION: The 3.7L is a non free-wheeling design engine. Therefore, correct engine timing is critical.
DR
NOTE: Components referred to as left hand or right hand are as viewed from the drivers position inside the vehicle.
NOTE: The blue link plates on the chains and the dots on the camshaft drive sprockets may not line up during the timing verification procedure. The blue link plates are lined up with the sprocket dots only when re-timing the complete timing drive. Once the timing drive is rotated blue link-to-dot alignment is no longer valid.
Engine base timing can be verified by the following
procedure:
(1) Remove the cylinder head covers. Refer to the
procedure in this section.
(2) Using a mirror, locate the TDC arrow on the front cover (Fig. 96). Rotate the crankshaft until the mark on the crankshaft damper is aligned with the TDC arrow on the front cover. The engine is now at TDC.
Fig.96EngineTopDeadCenter(TDC)Indicator
Mark
1 - TIMING CHAIN COVER 2 - CRANKSHAFT TIMING MARKS
(3) Note the location of the V6 mark stamped into the camshaft drive gears. If the V6 mark on each camshaft drive gear is at the twelve o’clock position, the engine is at TDC on the exhaust stroke. If the V6
mark on each gear is at the six o’clock position, the engine is at TDC on the compression stroke. (Fig. 100)DR VALVE TIMING (Continued)
(4) If both of the camshaft drive gears are off in the same or opposite directions, the primary chain or both secondary chains are at fault. Refer to Timing Chain and Sprockets procedure in this section.
(5) If only one of the camshaft drive gears is off and the other is correct, the problem is confined to one secondary chain. Refer to Single camshaft tim- ing, in this procedure.
(6) If both camshaft drive gear V6 marks are at the twelve o’clock or the six o’clock position the engine base timing is correct. Reinstall the cylinder head covers.
ENGINE - 3.7L
9 - 77
TIMING - SINGLE CAMSHAFT
NOTE: to adjust the timing on one camshaft, pre- form the following procedure.
(1) Using Chain Tensioner Wedge (Fig. 99), Special Tool 8379, stabilize the secondary chain drive. For reference purposes, mark the chain-to-sprocket posi- tion. (Fig. 98)
(2) Remove the camshaft drive gear retaining bolt.
COUNTER BALANCE SHAFT TIMING
(1) Ensure that the engine is at TDC with both camshaft sprocket V6 marks in the 12 o’clock posi- tion. (Fig. 100)
(2) Look down the left cylinder head chain cavity. The timing dot on the counter balance shaft drive gear should be in the 6 o’clock position (Fig. 97).
Fig.98SECURINGTIMINGCHAINTENSIONER
USINGTIMINGCHAINWEDGE
1 - CYLINDER HEAD 2 -SPECIAL TOOL 8379
3 - TIMING CHAINFig.97COUNTERBALANCESHAFTALIGNMENT
MARKS 1 - COUNTERBALANCE SHAFT GEAR 2 - TIMING MARK 3 - IDLER SPROCKET GEAR
ENGINE - 3.7L
9 - 78
VALVE TIMING (Continued)DR
(5) Using Special Tool 8428 Camshaft Wrench, rotate the camshaft until the alignment dowel on the camshaft is aligned with the slot in the camshaft drive gear.
CAUTION: Remove excess oil from camshaft sprocket retaining bolt before reinstalling bolt. Fail- ure to do so may cause over-torqueing of bolt resulting in bolt failure.
(6) Position the camshaft drive gear onto the cam- shaft, remove oil from bolt then install the retaining bolt. Using Special Tools, Spanner Wrench 6958 with Adapter Pins 8346 and a suitable torque wrench, Tighten retaining bolt to 122 N·m (90 ft. Lbs.).
(7) Remove Special Tool 8379. (8) Rotate the crankshaft two full revolutions, then verify that the camshaft drive gear V6 marks are in fact aligned.
(9) Install the cylinder head covers. Refer to Cylin-
der Head Cover in this section.
Fig.99CAMSHAFTDRIVEGEARREMOVAL/
INSTALLATION
1 - SPECIAL TOOL 8279 TIMING CHAIN WEDGE 2 - CAMSHAFT DRIVE GEAR 3 - RETAINING BOLT 4 - CYLINDER HEAD
(3) Carefully remove the camshaft drive gear from
the camshaft.
(4) Re-index the camshaft drive gear in the chain until the V6 mark is at the same position as the V6
mark on the opposite camshaft drive gear.1 - LEFT CYLINDER HEAD
2 - RIGHT CYLINDER HEAD
Fig.100CAMSHAFTSPROCKETV6MARKS(#1TDC,Exhauststroke)
DR
ENGINE - 3.7L
9 - 79
BALANCE SHAFT REMOVAL
(1) Remove the primary and secondary timing
chains. Refer to TIMING CHAIN and SPROCKET.
NOTE: The balance shaft and gear are serviced as an assembly. Do not attempt to remove the gear from the balance shaft.Remove the retaining bolt from the counterbalance shaft thrust plate (Fig. 101).
Fig.102CounterbalanceShaftRemoval/Installation
Tool
1 - COUNTERBALANCE SHAFT REMOVAL AND INSTALLATION TOOL 2 - COUNTERBALANCE SHAFT THRUST PLATE
Fig.101CounterbalanceShaftRetainingPlate
1 - IDLER SHAFT 2 - COUNTERBALANCE SHAFT THRUST PLATE 3 - COUNTERBALANCE SHAFT DRIVE GEAR 4 - RETAINING BOLT
(2) Using Special Tool 8641 Counterbalance shaft remover/installer tool, remove the counterbalance shaft from the engine (Fig. 102).
INSTALLATION
NOTE: The balance shaft and gear are serviced as an assembly. Do not attempt to remove the gear from the balance shaft.
(1) Coat
counterbalance shaft bearing journals
with clean engine oil.
NOTE: The balance shaft is heavy, and care should be used when installing shaft, so bearings are not damaged.
(2) Using Special Tool 8641 Counterbalance shaft remover/installer tool, carefully install counterbal- ance shaft into engine.
(3) Install Counterbalance
thrust plate retaining bolt finger tight.Do not tighten bolt at this time.
shaft
(4) Position the right side of the thrust plate with
the right chain guide bolt, install bolt finger tight.
(5) Torque the thrust plate retaining bolt to 28
N·m (250 in. lbs.).
be installed.
(6) Remove the chain guide bolt so that guide can
IDLER SHAFT REMOVAL
(1) Remove the primary and secondary timing chains and sprockets. Refer to procedure in this sec- tion.
NOTE: To remove the idler shaft, it is necessary to tap threads into the shaft, to install the removal tool.
(2) Using a 12 mm X 1.75 tap, cut threads in the
idler shaft center bore.
(3) Cover the radiator core with a suitable cover.
DR
ENGINE - 3.7L
9 - 80
IDLER SHAFT (Continued)CAUTION: Use care when removing the idler shaft, Do not strike the radiator cooling fins with the slide hammer.
(4) Using Special Tool 8517 Slide Hammer, remove
the idler shaft.
INSTALLATION
(1) Thoroughly clean the idler shaft bore. (2) Position the idler shaft in the bore.
NOTE: The two lubrication holes in the idler shaft do not require any special alignment.
NOTE: Before using the retaining bolt to install the idler shaft, coat the threads and the pilot on the idler shaft, with clean engine oil.
(3) Using the primary idler sprocket retaining bolt and washer, carefully draw the idler shaft into the bore until fully seated.
(4) Coat the idler shaft with clean engine oil. (5) Install the timing chains and sprockets. Refer
to procedure in this section.
TIMING BELT / CHAIN COVER(S) REMOVAL
(1) Disconnect the battery negative cable. (2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Remove electric cooling fan and fan shroud
assembly.
