Jeep UNIVERSAL CJ-2A - Page 72

'Jeep' UNIVERSAL and 'Jeep' DISPATCHER
E
FIG. 87--CONNECTING ROD OFFSET
The .001" and .002" undersize bearings are for use
with standard size crankshafts having slightly
worn crankpins that do not require grinding. The
.012" undersize bearings are for use with slightly
worn crankshafts that have been previously ground
for .010" undersize bearings.
Should it be necessary to replace the bearings due
to wear, replacement of piston rings and piston
pins is also recommended.
NOTE: Should it be necessary to replace a scored
or burned No. 1 connecting rod bearing, see Par.
E-93 regarding timing gear oil jet.
E-49. Connecting Rod Bearing Inspection
The bearing fits may be roughly checked by shaking
the connecting rod by hand, prior to removal of
the bearing cap, to determine if it is loose on the
crankshaft. The crankpins must be carefully in-
spected as detailed previously in Par. E-41. Worn
crankpins will require undersize bearings. Scored,
flaked, or worn bearings must be replaced.
E-50. Installing Connecting Rod Bearings
New bearings must be installed so that the oil
spray hole in the upper bearing half aligns with
the oil spray hole in the connecting rod. Each
bearing cap must be installed to seat evenly on the
connecting rod from which it was removed, and in
the same position. After wiping and carefully in-
specting the bearing bore in the connecting rod,
install the proper bearing. Never file either the
bearing cap or the bearing to compensate for too
much clearance. Do not use shims under a bearing
cap or behind .a bearing shell. Do not run a new
bearing half with a worn half.
The desired running fit (difference between the
diameter of the crankpin and the inside diameter
of the fitted bearing) for a connecting rod bearing
is .003" to .0025" [0,0076 a 0,0635 mm.]. With a
dimension in excess of this standard running fit, a
satisfactory bearing replacement cannot be made
and it will be necessary to regrind the crankshaft.
Install the bearing lower half and the connecting
rod cap and draw the cap bolt nuts down equally
and only slightly tight. Move the connecting rod
endwise, one way or the other, on the crankshaft
to be sure the bearing is not tight. Pull the nuts
tighter, first one then the other, a little at a time,
and keep trying the fit of the rod on the crankshaft
by hand until the recommended torque of 35
to 45 lb-ft. [4,8 a 6,2 kg-m.] is reached. If the
bearings are of the correct size, and have been
properly lubricated with light engine oil before in-
stallation, the connecting rod should be easy to
slide back and forth parallel to the crankpin.
If the connecting rod is tight on the crankshaft, a
larger bearing is required. If there is no binding
or tightness, it is still necessary to check clearance
to guard against too loose a fit. The use of "Plasti-
gage" or shim stock of the proper size to measure
.001" [0,0254 mm.] clearance is recommended for
checking connecting rod bearing clearances. This
is the same material recommended for checking
crankshaft main bearings and the method of check-
ing is similar. Referto Par. E-46 or E-47. C~nnect
ing rod bearings are fitted to the same clearance as
the main bearings but the torque specified for con-
necting rod cap bolts is different.
E-51. Connecting Rod Side Play
Check the connecting rod side play with a feeler
gauge as showr. in Fig. 88. The side clearance is
.004" to .010" [0.1016 a 0,254 mm.].
FIG. 88-CONNECTING ROD SIDE PLAY
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