Jeep UNIVERSAL CJ-2A - Page 37

D
L4-134 ENGINE
10444
FIG. 42-PISTON RING INSTALLATION
The letters T or TOP on the upper edge indicate
how the ring is to be installed.
D-34. Piston Ring Application Chart
Cylinder Bore
Correct
Ring Gap End Gap
Oversize
Ring Size Fitting
Std. to .009 •
Std.
None .007' to .045'
[a 0.483 mm.)
[0,1778 a 1,1430 mm.J
.010'10 .019' -.020'
File fit
.007' to .017'
[0,254 a p,4826 mm.J
[0,1778 a 0,4318 mm.J
.020' to .024'
-.020'
None .007' to .029 •
[0,508
a 0,6096 mm.J
[0,1778 a 0,7366 mm.)
.025' to .029' -.030' File fit .007' to .017'
[0,635 a 0,7366 mm.J
.030 • to .034 •
-.030'
None .007 • to .029'
[0,762 a 0,8636 mm.J
----
.035 • to .039 •
-.040'
File fit .oo1· to.o17'
[0,8890 a 0,9906 mm.J
.040' [1,016 mm.J -.040' None .007' to .017"
D-35. Crankshaft
The crankshaft is machined from a heat-treated
carbon steel forging and is carefully balanced both
dynamically and statically. The crankshaft is
supported by three replaceable main bearings. The
front main bearing is flanged to take the end
thrust of the crankshaft. A flanged section on the
rear of the crankshaft acts as an oil slinger. While
the crankshaft is out of the engine, handle it care-
fully to prevent damage to the connecting rod
crankpins and the main bearing journals. See Fig.
43.
D-36. Crankshaft Inspection and Repair
Clean out the drilled oil passages in the crankshaft
journals with a small rifle brush making sure to
get rid of all sludge or gum deposits. Blow out
the passages with compressed air after cleaning.
Clean the crankshaft thoroughly with a suitable
cleaning solvent. Inspect the crankshaft for cracks,
alignment, and condition of the crankpins and the
main bearing journals. Use magnaflux equipment,
if available, to check for cracks or structural flaws.
Cracks, misalignment, and scored or worn journals
and crankpins necessitate crankshaft repair or
replacement.
36
Check crankshaft counterweights to be sure they
are not loose.
D-37. Checking Crankshaft Alignment
To check alignment, mount the crankshaft in the
cylinder block with the front and rear bearings in
place but with the intermediate bearing removed.
With a dial indicator mounted on the crankcase
and the indicator button resting on the inter-
mediate bearing journal, slowly rotate the crank-
shaft and note the reading on the indicator dial.
Install the intermediate bearing and remove first
the front and then the rear bearings to repeat the
0peration with the dial indicator, checking the
front and rear bearing journals. The maximum
allowable run-out is .002
11
[0,0508 mm.].
,
\I
FIG. 43-CRANKSHAFT AND BEARINGS
!-Bearing Dowel
2-Front Bearing
3-Center Bearing
4-Rear Bearing
5-Flywheel Bolt
6-Crankshaft
7-Flywheel Dowel-Bolt
8-Crankshaft Shim
9-Thrust Washer
10-Woodruff Key No. 9
11-Crankshaft Gear
12-Gear Spacer
13-0il Slinger
D-38. Checking Main Bearing Journals
An ordinary 3
11
[7,62 em.] micrometer may be used.
The standard journal diameter is 2.3341
11
to
2.3331
11
[5,9286 a 5,9261 em.] for all main bearings.
Allowable taper or out-of-round of the journals is
.001
11
[0,025 mm.].
.
D-39. Checking Connecting Rod Crankpins
Check the crankpin diameters with a micrometer
to ensure that they are not out-of-round or tapered
more than .001
11
[0,025 mm.] The standard crank-
pin diameter is 1.9383
11
to 1.9375
11
[4,9233 a 4,9213
em.].
D-40. Crankshaft Pilot Bushing
Inspect the crankshaft pilot bushing in the flywheel
end of the crankshaft. To remove the bushing use
a clutch shaft pilot bushing remover. Fig. 183 and
184. The pilot bushing is installed with a driver and
then burnished with a clutch shaft pilot bushing
burnisher.