Page 1649 of 2438
cylinder bore. Check gap with feeler gauge (Fig. 7).
Refer to (Fig. 8) for specification.(2) Check piston ring to groove clearance; Refer to
Piston Ring Specification Chart (Fig. 8).
Fig. 4 Remove Piston Rings
Fig. 5 Checking Cylinder Bore Size
Fig. 6 Piston Clearance and Wear
Fig. 7 Check Gap on Piston Rings
Fig. 8 Piston Ring Specification Chart
Fig. 9 Piston Ring Clearance
Ä 3.0L ENGINE 9 - 83
Page 1650 of 2438

PISTON RINGSÐINSTALLATION
(1) The No. 1 and No. 2 piston rings have a differ-
ent cross section. Install rings with manufacturers
mark and size mark facing up, to the top of the pis-
ton (Fig. 10).
CAUTION: Install piston rings in the following or-
der:
(a) Oil ring expander.
(b) Upper oil ring side rail.
(c) Lower oil ring side rail.
(d) No. 2 Intermediate piston ring.
(e) No. 1 Upper piston ring.
(2) Install the side rail by placing one end between
the piston ring groove and the expander. Hold end
firmly and press down the portion to be installed un-
til side rail is in position. Do Not use a piston ring
expander (Fig. 11).
(3) Install upper side rail first and then the lower
side rail. (4) Install No. 2 piston ring and then No. 1 piston
ring (Fig. 12). (5) Position piston ring end gaps as shown in (Fig.
13). (6) Position oil ring expander gap at least 45É from
the side rail gaps but noton the piston pin center or
on the thrust direction. (7) Connecting rod front mark 72 must always face
forward, toward timing belt end. (Fig. 14) (8) Install the piston and connecting rod assembly
into there respective bore from the cylinder block
top.
CAUTION: Piston assemblies are not to be inter-
changed from bank to bank.
(9) Check alignment marks made during disassem-
bly and that bearing position notches new or used
are on the same side as shown in (Fig. 15).
CONNECTING ROD CLEARANCE
(1) Following procedures specified in the Standard
Service Procedures Section for Measuring Main Bear-
ing Clearance and Connecting Rod Bearing Clear-
ance. (Fig. 16). Refer to (Fig. 18) for specifications.
Fig. 10 Piston Ring Installation
Fig. 11 Installing Side Rail
Fig. 12 Installing Upper and Intermediate Rings
Fig. 13 Piston Ring End Gap Position
9 - 84 3.0L ENGINE Ä
Page 1651 of 2438
(2) Tighten nuts to 52 N Im (38 ft. lbs.).
(3) Remove connecting rod cap and measure Plas-
tigage (Fig. 16).
CAUTION: Do not rotate crankshaft or the Plasti-
gage may be smeared.
CONNECTING ROD SIDE CLEARANCE
Using a feeler gauge, check connecting rod side
clearance (Fig. 17). Refer to (Fig. 18) for specifica-
tion.
Fig. 14 Identify Piston/Rod Assembly for Cylinder Installation
Fig. 15 Connecting Rod and Cap
Fig. 16 Connecting Rod Checking BearingClearance
Fig. 17 Checking Connecting Rod Side Clearance
Fig. 18 Connecting Rod Clearance Specifications
Ä 3.0L ENGINE 9 - 85
Page 1652 of 2438

CRANKSHAFT AND CYLINDER BLOCK, ASSEMBLY SERVICE
CRANKSHAFT SERVICE
The crankshaft is supported in four main bearings.
All upper bearing shells in the crankcase have oil
grooves. All lower bearing shells in stalled in the
monoblock main bearing cap are plain. Crankshaft
end play is controlled by thrust washers on the num-
ber three main bearing journal.
CRANKSHAFTÐREMOVAL
(1) Remove front mounted oil pump assembly and
gasket (Figs. 1 and 2). (2) Remove rear oil seal retainer and seal as as-
sembly (Fig. 3). (3) Release monoblock main bearing cap bolts
evenly. Remove lower bearing shells and identify for
reassembly. (4) Lift out crankshaft and remove upper thrust
washers from each side of number three main bear-
ing in the crankcase (Fig. 1).
INSPECTION
Visually check the main and connecting rod bear-
ing journals for wear, scuffs or scoring and replace if
necessary.
CRANKSHAFT OIL CLEARANCE
MECHANICAL MEASUREMENT
Measure the journal outside diameter and the main
bearing inside diameter (Figs. 4 and 5). If the clear-
ance exceeds the specifications limit (Fig. 6). Replace
the main bearing(s) and if necessary replace the
crankshaft.
Fig. 1 Crankshaft and Cylinder Block
Fig. 2 Oil Pump Assembly
9 - 86 3.0L ENGINE Ä
Page 1653 of 2438

PLASTIGAGE MEASUREMENT
(1) Remove oil from journal and bearing shell.
(2) Install crankshaft.
(3) Cut plastigage to same length as width of the
bearing and place it in parallel with the journal axis.
(Fig. 7). (4) Install the main bearing cap carefully and
tighten the bolts to specified torque.
CAUTION: Do not rotate crankshaft or the plasti-
gage will be smeared.
(5) Carefully remove the bearing cap and measure
the width of the plastigage at the widest part using
the scale on the plastigage package (Fig. 8). Refer to
specification (Fig. 6) for proper clearances. Also see
Measuring Main and Connecting Rod Bearing Clear-
ance in Standard Service Procedures.
CRANKSHAFT BEARINGS
INSTALLATION
(1) Install upper main bearing shells making cer-
tain oil holes are in alignment, and bearing tabs seat
in block tabs. All upper bearings have oil grooves
(Fig. 9). THRUST BEARINGS. Crankshaft thrust bear-
ings (washers) are installed at journal #3 separately
from the radial bearings. Thrust bearings shown in
Fig. 3 Rear Seal Assembly
Fig. 4 Measure Crankshaft Journal O.D.
Fig. 5 Measure Main Bearing I.D.
Fig. 6 Crankshaft Clearance Specification
Fig. 7 Measure Oil Clearance with Plastigage
Ä 3.0L ENGINE 9 - 87
Page 1654 of 2438

(Fig. 9) are different, one has end positioning tabs,
while the other is plain. One pairof each thrust
washers are installed into the block and one pair
into the main bearing cap (Fig. 9). (2) Apply a thin film of grease to plain side of
thrust washers and position them on each side of
number three main bearing. Grooved surface towards
crankshaft. (3) Oil the bearings and journals and install crank-
shaft. (4) Install lower main bearing shells without oil
grooves in monoblock cap. (5) Install one pair of thrust washers in cap. Refer
to Thrust Bearings (Fig. 9). (6) Carefully install bearing cap with arrows (Fig.
10) toward timing belt end. (7) Oil the bearing cap bolt threads, install and
tighten bolts progressively in sequence shown in
(Fig. 9) to 80 N Im (60 ft. lbs.) torque.
CHECKING CRANKSHAFT END PLAY
(1) Mount a dial indicator to front of engine, locat-
ing probe on nose of crankshaft (Fig. 11). (2) Move crankshaft all the way to the rear of its
travel. (3) Zero the dial indicator.
(4) Move crankshaft all the way to the front and
read the dial indicator. Refer to (Fig. 6) for specifica-
tion.
CRANKSHAFT OIL SEALS SERVICE
REAR CRANKSHAFT SEAL RETAINER
(1) Install rear crankshaft oil seal in housing with
Special Tool MD998718 (Fig. 12). (2) Apply (Mopar Silicone Rubber Adhesive Seal-
ant or equivalent) to oil seal housing (Fig. 13) per
procedure detailed in form-in-place gasket section in
Standard Service Procedures.
Fig. 9 Install Main Bearings
Fig. 8 Measuring Clearance
9 - 88 3.0L ENGINE Ä
Page 1655 of 2438
(3) Apply light coating of engine oil to the entire
circumference of oil seal lip. (4) Install seal assembly on cylinder block and
tighten bolts to 12 N Im (104 in. lbs.)
FRONT CRANKSHAFT OIL PUMP AND OIL
SEAL
(1) Install oil pump gasket and oil pump case
(Figs. 1 and 14). CAUTION: Install bolts, depending on length in lo-
cations shown in (Fig. 14).
(2) Using front crankshaft oil seal installer Special
Tool MB998306 install oil seal in oil pump (Fig. 15).
CYLINDER BLOCK
Inspect cylinder block for scratches, cracks and rust
or corrosion, and repair or replace as required.
Fig. 10 Crankshaft Main Bearing Cap
Fig. 11 Checking Crankshaft End PlayFig. 12 Install Crankshaft Rear Oil Seal
Ä 3.0L ENGINE 9 - 89
Page 1656 of 2438

(1) Clean cylinder block and check top surface for
distortion with a straight edge and thickness gauge
(Fig. 16). (2) Top surface must be flat within: ²
Standard Value: 0.05 mm (.002 inch)
² Service Limit 0.1 mm (.003 inch)
CAUTION: Maximum of 0.2mm (.008 inch) is permit-
ted. This is a combined total dimension of stock re-
moval from cylinder head (if any) and block top
surface.
BORING CYLINDER
Examine cylinder walls for scuffs, scoring and mea-
sure cylinder bore for out-of-round or taper. If defec-
tive, bore cylinder to oversize. Measure at points
shown in (Fig. 17). Four oversize pistons are available (0.25mm (.010
inch) 0.50mm (.020 inch) 0.75mm (.030 inch) and
1.0mm (.039 inch). Determine oversize piston on ba-
sis of largest cylinder bore.
(1) Bore to specified clearance between the piston
O.D. and cylinder. The measuring point of the piston
O.D. is shown in (Fig. 18). (2) Based on measured piston O.D., calculate bor-
ing finish dimension. Boring finish dimension equals
piston O.D. plus 0.03 to 0.05 mm (.0012 to .002 inch)
Fig. 13 Apply Sealant to Oil Seal Housing
Fig. 14 Oil Pump
Fig. 15 Crankshaft Front Oil Seal
Fig. 16 Distortion Check
Fig. 17 Measure Cylinder Bore
9 - 90 3.0L ENGINE Ä