Jeep Cherokee 2000 Service Manual - page 775
If the clearance exceeds specification using a pair
of 0.051 mm (0.002 inch) undersize bearing inserts,
measure
crankshaft
journal
diameter
with
a
micrometer. If the journal diameter is correct, the
crankshaft bore in the cylinder block may be mis-
aligned, which requires cylinder block replacement or
machining to true bore.
Replace the crankshaft or grind to accept the
appropriate undersize bearing inserts if:
• Journal diameters 1 through 6 are less than
63.4517 mm (2.4981 inches)
• Journal 7 diameter is less than 63.4365 mm
(2.4975 inches).
Once the proper clearances have been obtained,
proceed to Crankshaft Main Bearing—Installation.
MAIN BEARING JOURNAL DIAMETER
(CRANKSHAFT REMOVED)
Remove the crankshaft from the cylinder block
(refer to Cylinder Block - Disassemble).
Clean the oil off the main bearing journal.
Determine the maximum diameter of the journal
with a micrometer. Measure at two locations 90°
apart at each end of the journal.
The maximum allowable taper and out of round is
0.013 mm (0.0005 inch). Compare the measured
diameter with the journal diameter specification
(Main Bearing Fitting Chart). Select inserts required
to obtain the specified bearing-to-journal clearance.
Install the crankshaft into the cylinder block (refer
to Cylinder Block - Assemble and Crankshaft Main
Bearings - Installation).
MAIN BEARING FITTING CHART
Crankshaft Journals #1-6
Corresponding Crankshaft Bearing Insert
Color Code
Diameter
Upper Insert Size
Lower Insert Size
Yellow
63.5025 -63.4898 mm
Yellow - Standard
Yellow - Standard
(2.5001 - 2.4996 in.)
Orange
63.4898 - 63.4771 mm
Yellow - Standard
Blue - Undersize
0.025 mm (0.001 in.)
(2.4996 - 2.4991 in.)
0.0127 mm (0.0005 in.)
Undersize
Blue
63.4771 - 63.4644 mm
Blue - Undersize
0.025 mm (0.001 in.)
Blue - Undersize
0.025 mm (0.001 in.)
(2.4991 - 2.4986 in.)
0.0254 mm (0.001 in.)
Undersize
Green
63.4644 - 63.4517 mm
Blue - Undersize
0.025 mm (0.001 in.)
Green - Undersize
0.051 mm (0.002 in.)
(2.4986 - 2.4981 in.)
0.0381 mm (0.0015 in.)
Undersize
Red
63.2485 - 63.2358 mm
Red - Undersize
0.254 mm (0.010 in.)
Red - Undersize
0.254 mm (0.010 in.)
(2.4901 - 2.4896 in.)
0.254 mm (0.010 in.)
Undersize
XJ
4.0L ENGINE
9 - 85
SERVICE PROCEDURES (Continued)