Jeep Cherokee 2000 Service Manual - page 998
(11) FOR EXAMPLE: If the initial clearance was
0.0762 mm (0.003 inch), 0.025 mm (0.001 inch)
undersize inserts would reduce the clearance by
0.025 mm (0.001 inch). The clearance would be 0.002
inch and within specification. A 0.051 mm (0.002
inch) undersize insert would reduce the initial clear-
ance an additional 0.013 mm (0.0005 inch). The
clearance would then be 0.038 mm (0.0015 inch).
(12) Repeat the Plastigage measurement to verify
your bearing selection prior to final assembly.
(13) Once you have selected the proper insert,
install the insert and cap. Tighten the connecting rod
bolts to 45 N·m (33 ft. lbs.) torque.
Slide snug-fitting feeler gauge between the con-
necting rod and crankshaft journal flange (Fig. 33).
Refer to Engine Specifications for the proper clear-
ance. Replace the connecting rod if the side clearance
is not within specification.
FITTING CRANKSHAFT MAIN BEARINGS
INSPECTION
Wipe the inserts clean and inspect for abnormal
wear patterns and for metal or other foreign material
imbedded in the lining. Normal main bearing insert
wear patterns are illustrated (Fig. 34). In general the
lower bearing half will a heaver wear pattern.
NOTE: If any of the crankshaft journals are scored,
remove the engine for crankshaft repair.
Inspect the back of the inserts for fractures, scrap-
ings or irregular wear patterns.
Inspect the upper insert locking tabs for damage.
Replace all damaged or worn bearing inserts.
FITTING BEARINGS (CRANKSHAFT INSTALLED)
The main bearing caps, numbered (front to rear)
from 1 through 5 have an arrow to indicate the for-
ward position. The upper main bearing inserts are
grooved to provide oil channels while the lower
inserts are smooth.
Each bearing insert pair is selectively fitted to its
respective journal to obtain the specified operating
clearance. In production, the select fit is obtained by
using various-sized color-coded bearing insert pairs
as listed in the Main Bearing Fitting Chart. The
bearing color code appears on the edge of the insert.
The size is not stamped on bearing inserts used
for engine production.
The main bearing journal size (diameter) is identi-
fied by a color-coded paint mark on the adjacent
cheek. The rear main journal, is identified by a color-
coded paint mark on the crankshaft rear flange.
When required, upper and lower bearing inserts of
different sizes may be used as a pair. A standard size
insert is sometimes used in combination with a 0.025
mm (0.001 inch) undersize insert to reduce the clear-
ance by 0.013 mm (0.0005 inch). Never use a pair
of bearing inserts with greater than a 0.025 mm
(0.001 inch) difference in size. Refer to the
Bearing Insert Pair Chart.
Fig. 33 Checking Connecting Rod Side Clearace—
Typical
Fig. 34 Main Bearing Wear Patterns
1 – UPPER INSERT
2 – NO WEAR IN THIS AREA
3 – LOW AREA IN BEARING LINING
4 – LOWER INSERT
BEARING INSERT PAIR CHART
INSERT
CORRECT
INCORRECT
UPPER
STANDARD
STANDARD
LOWER
0.025 mm
(0.001 in.)
UNDERSIZE
0.051 mm
(0.002 in.)
UNDERSIZE
XJ
2.5L ENGINE
9 - 23
SERVICE PROCEDURES (Continued)