shells (7 and 9, fig. 103). Mark the bearing caps so they can be installed in their original positions. Push the
exposed upper bearing shells (7 and 9) counterclockwise (facing the front of the engine) until they can be
removed. Keep each pair of bearing shells together and tag them so they can be installed in their original
positions.
(3) Support the crankshaft (8) to prevent it from dropping. Remove four cap screws (9, fig. 106) and the front
and rear bearing caps (8 and 11) together with the front and rear bearing shells (7, fig. 103).
(4) Remove the crankshaft and place it on a clean surface. Do not use chains to support the crankshaft or the
bearing surfaces will be marred. Remove the cap screw (2), lockwasher (3) and washer (4). Remove the
crankshaft pulley (5) and gear (6) with a gear and bearing puller (par. 179). Do not lose the woodruff keys
(11 and 12).
b. Inspection.
(1) Inspect the crankshaft gear for broken or chipped teeth. Replace the gear if it is damaged in any way.
Examine the crankshaft pulley for cracks and replace it if damaged.
(2) Inspect the crankshaft bearing surfaces for cuts, scoring and cracks. Check the crankshaft journals with an
0to 4-inch outside micrometer caliper (par. 179) for wear, concentricity and taper. The journals should be
3.748 to 3.749 inches in diameter. Set the crankshaft on center blocks and check for straightness using a
dial indicator (par. 179) or a suitable stand and setup.
(3) Inspect the bearings for scoring and wear. Measure the thickness of the bearing shells. The bearing
thickness should be 0.1250 to 0.1255 inches. If any bearing shell is worn beyond the minimum, replace all
the bearings. This will eliminate the danger of a shutdown when another bearing fails.
c. Repair. Remove small defects in the crankshaft journals with strips of emery cloth well oiled. Wrap the strip
around the journal to prevent lapping the journal to a oval shape. If the crankshaft is worn excessively or bent, it must be
ground in a crankshaft grinder (par. 179) or replaced with an undersize crankshaft which is: available in two sizes:
0.010and 0.030 inch undersize. By installing an undersize crankshaft, the engine compressor can be put in operating
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