Jeep 1979 CJ-5 Technical & Service Manual page 126

ENGINES 1B-65
Main Bearing Fitting Chart
Crankshaft Main Bearing Journal
Color Code and Diameter in
Inches (Journal Size)
Bearing Color Code
Upper Insert Size
Lower I nsert Size
Yellow - 2 . 7 4 8 9 t o 2.7484 (Standard)
Orange - 2 . 7 4 8 4 t o 2.7479 (0.0005 Undersize)
Black - 2 . 7 4 7 9 t o 2.7474 (0.001 Undersize)
Green - 2 . 7 4 7 4 t o 2.7469 (0.0015 Undersize)
Red - 2 . 7 3 8 9 t o 2.7384 (0.010 Undersize)
Yellow — Standard
Yellow — Standard
Black — .001-inch Undersize
Black — .001-inch Undersize
Red — .010-inch Undersize
Yellow — Standard
Black - .001-inch Un<
Black - .001-inch Urn
Green - .002-inch Un<
Red - .010-inch Un<
Service replacement bearing inserts are available as
pairs in the following sizes: standard, 0.001-inch under-
size, 0.002-inch undersize, 0.010-inch undersize, and
0.012-inch undersize. The bearing size is stamped on the
back of service replacement inserts.
NOTE: The 0.012-inch undersize insert is not used in
production.
Removal
This procedure may be used with engine in vehicle.
(1) Drain engine oil and remove pan.
(2) Remove main bearing cap and insert.
(3) Remove lower insert from bearing cap.
(4) Remove upper insert by loosening all other bear-
ing caps and inserting cotter pin about 1/2-inch (14 mm)
long in crankshaft oil hole. Bend cotter pin as shown in
figure 1B-105.
(5) With pin in place, rotate shaft so that upper
bearing insert is rotated in direction of its locking tab.
(6) Remove and inspect remaining bearings in same
manner.
BEND H E A D T O FOLLOW
CONTOUR OF JOURNAL
6 0 7 6 3
Fig. 1 B-1 OS Upper Main Bearing Removal Tool
Inspection
(1) Wipe lower insert clean and inspect for abnor-
mal wear pattern and for dirt or metal imbedded in
iize
;IZE *
IIZE
ize
6 0 2 7 3
lining. A normal main bearing wear pattern is shown in
figure 1B-106.
NOTE: If the crankshaft journal is scored, remove the
engine for crankshaft repair.
UPPER
P A T T E R N ON
LOWER B E A R I N G
6Q7S2
Fig. 1 B-106 Normal Main Bearing Wear Pattern
(2) Inspect back of insert for fractures, scrapings or
irregular wear pattern.
(3) Inspect locking tab for damage.
' (4) Replace damaged or worn bearing inserts.
Measuring Main Bearing Clearance with Plastigage (Crankshaft Installed)
(1) Support weight of crankshaft with jack placed
under counterweight adjacent to main bearing being
checked.
NOTE: Check clearance of one bearing at a time. ALL
other bearings must remain tightened.
(2) Remove main bearing cap and insert.
(3) Wipe insert and exposed portion of crankshaft
journal clean.
(4) Place strip of Plastigage across full width of
bearing insert.