Crankshaft End Play Measurement; Crankshaft Main Bearings; Measuring Crankshaft End Play - Jeep J-10 Series 1982 Technical & Service Manual

An oil slinger is located at the rear main journal,
inboard of the rear oil seal. The component parts and
crankshaft are first individually balanced and then the
complete assembly is balanced as a unit.
Service replacement vibration dampers, crankshafts,
flywheels, drive plates, torque converters and clutch
components are balanced individually and may be re
placed as required without balancing the complete
assembly.
Removal or Replacement
If the crankshaft is damaged to the extent that re
conditioning is not feasible, it must be replaced. Re
moval and installation procedures are outlined under
Cylinder Block.
Crankshaft End Play Measurement
The crankshaft end play is controlled by the No. 3
main bearing inserts, which are flanged for this
purpose.
(1) Attach dial indicator to cylinder block adjacent
to No. 3 main bearing (fig. 1B-91).
NUMBER
THREE
MAIN
BEARING
CAP
I i
60123
Hg. 1B-91 Measuring Crankshaft End Play
(2) Pry shaft forward with flat-bladed screwdriver
and with dial indicator stem on face of crankshaft
counterweight, set to zero.
(3) Pry shaft fore and aft and observe dial in
dicator. The end play is the difference between the high
and low measurements. The correct crankshaft end play
is 0.0015 to 0.0065 inch (0.0020 to 0.0025 desired) [0.038 to
0.165 mm (0.051 to 0.064 mm desired)].
ENGINES 1B-57
(4) If end play is not within specifications, inspect
crankshaft bearing thrust faces for wear. If wear is
apparent, replace thrust bearing and measure end play.
If end play is still not within specifications, replace
crankshaft.
NOTE: When replacing the thrust bearings, pry the
crankshaft fore and aft to align the faces of the thrust
bearings before the final tightening.
Crankshaft Main Bearings
The main bearings are a steel-backed, micro-babbitt,
precision type. The main bearing caps are numbered
(front to rear) from 1 through 7, and an arrow indicates
the forward position. The upper main bearing inserts
are grooved while the lower inserts are smooth.
Each bearing is selectively fitted to its respective jour
nal to obtain the desired operating clearance. In produc
tion, the select fit is obtained by using various sized
color coded bearing inserts as described in the Main
Bearing Fitting Chart. The bearing color code appears
on the edge of the insert.
NOTE: Bearing size is not stamped on inserts installed
during production assembly.
The main bearingjournal size is identified in produc
tion by a color-coded paint mark on the adjacent cheek
toward the flanged (rear) end of the crankshaft, except
for the rear main journal, where the paint mark is 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 0.001-
inch (0.025 mm) undersize insert to reduce clearance by
0.0005 inch (0.013 mm).
Example:
Bearing Insert Pairs
Insert
Correct Incorrect
Upper
Standard Standard
Lower
0.001-inch <0.025mm)
undersize
0.002-inch (0.051 mm)
undersize
70242
CAUTION: Never use a pair of bearing inserts with
greater than O.OOl-inch (0.025 mm) difference in size.
CAUTION: When replacing bearinginserts, all the odd
size inserts must be either all on the top (in blockt or nil
on the bottom (in main bearing caps).
Service replacement bearing inserts are available as
pairs in the following sizes: standard, 0.001-, 0.002-,
0.010- and 0.012-inch undersize. The size is stamped on
the back of service replacement inserts.